Wednesday 17 July 2013

Italians, a mixed race after the Roman Empire

RACE MIXTURE IN THE ROMAN EMPIRE
by TENNEY FRANK

The following article by Tenney Frank originally appeared in the American
Historical Review (July 1916, vol. 21, no. 4: 689–708). Frank (1876–1939),
an American historian, was professor at Johns Hopkins University, Baltimore,
Maryland, and the author of several books, including A History of Rome
(1923), Economic History of Rome (1920), Catullus and Horace (1928),
and Roman Imperialism (1914).

There is one surprise that the historian usually experiences upon his ﬁrst
visit to Rome. It may be at the Galleria Lapidaria of the Vatican or at the
Lateran Museum, but, if not elsewhere, it can hardly escape him upon
his ﬁrst walk up the Appian Way. As he stops to decipher the names upon the
old tombs that line the road, hoping to chance upon one familiar to him from
his Cicero or Livy, he ﬁnds praenomen and nomen promising enough, but
the cognomina all seem awry. L. Lucretius Pamphilus, A. Aemilius Alexa, M.
Clodius Philostorgus do not smack of freshman Latin. And he will not readily
ﬁnd in the Roman writers now extant an answer to the questions that these
inscriptions invariably raise. Do these names imply that the Roman stock was
completely changed after Cicero’s day, and was the satirist recording a fact
when he wailed that the Tiber had captured the waters of the Syrian Orontes?
If so, are these foreigners ordinary immigrants, or did Rome become a nation
of ex-slaves and their offspring? Or does the abundance of Greek cognomina
mean that, to a certain extent, a foreign nomenclature has gained respect, so that
a Roman dignitary might, so to speak, sign a name like C. Julius Abascantus
on the hotel register without any misgivings about the accommodations?
Unfortunately, most of the sociological and political data of the empire are
provided by satirists. When Tacitus informs us that in Nero’s day a great many
of Rome’s senators and knights were descendants of slaves and the native stock
had dwindled to surprisingly small proportions, we are not sure whether we
are not to take it as an exaggerated thrust by an indignant Roman of the old
stock. At any rate, this, like similar remarks equally indirect, receives totally
different evaluation in the discussion of those who have treated of Rome’s
society, like Friedländer, Dill, Mommsen, Wallon, and Marquardt. To discover
some new light upon these fundamental questions of Roman history, I have
tried to gather such fragmentary data as the corpus of inscriptions might
afford. This evidence is never decisive in its purport, and it is always, by the
very nature of the material, partial in its scope, but at any rate it may help us 52 Vol. 5, No. 4

The Occidental Quarterly to interpret our literary sources to some extent. It has at least convinced me
that Juvenal and Tacitus were not exaggerating. It is probable that when these
men wrote a very small percentage of the free plebeians on the streets of Rome
could prove unmixed Italian descent. By far the larger part, perhaps ninety
percent, had Oriental blood in their veins.

My ﬁrst quest was for information about the stock of the ordinary citizen
of Rome during the empire. In the Corpus of Latin Inscriptions the editors, after
publishing the honorary and sepulchral inscriptions of the nobles and military
classes, followed by those of the slaves and humble classes which occur in the
columbaria, gave the rest of the city’s sepulchral inscriptions (19,260) in alphabetical order.

Of these I read the 13,900 contained in volume VI., parts 2 and
3, which, despite the occurrence of some slaves as well as of some persons of
wealth, represent on the whole the ordinary type of urban plebeians. A mere
classiﬁcation of all these names into lists of natives on the one hand and slaves
and foreigners on the other would be of little service, since, obviously, transient
foreigners are of little importance in estimating the stock of the permanent
population of Rome, and we must face the question at once whether or not
the slave and freedman stock permanently merged into the civil population.
Furthermore, such lists will be at everyone’s hand as soon as the index of the
sixth volume of CIL is published. In reckoning up the foreign stock, therefore,
I have counted only those who, according to the inscriptions, were presumably born at Rome.

A somewhat arbitrary deﬁnition of limits was necessary
since we are seldom given deﬁnite information about the place of birth, but
as I have used the same classiﬁcation for the free-born as for the slave-born
the results are valid for our purposes. For instance, in getting statistics of
birth, I have included all children under ten years of age, assuming that slave
children under that age would rarely be brought in from abroad; and if slaves
of this class are counted, the free-born of the same class must also be reckoned
with. I have also included slave and free-born children who appear to be with
father, mother, brother, or sister at Rome, since presumably they would have
been sundered from their family if they had been brought in from the foreign
market; and again, in order to reach fair results, the corresponding persons of
free birth are counted.

For reasons which will presently appear I have accepted
the Greek cognomen as a true indication of recent foreign extraction, and,
since citizens of native stock did not as a rule unite in marriage with liberty, a
Greek cognomen in a child or one parent is sufﬁcient evidence of status. As is
well known, certain Latin cognomina, e.g., Salvius, Hilarus, Fortunatus, were
so frequently borne by slaves and freedmen that they were apt to be avoided
by the better classes. Nevertheless, since no deﬁnite rule is attainable in the
matter, I have credited the bearers of all Latin names to the native stock in all
cases of doubt.

Classifying in this way the names of the aforesaid 13,900 inscriptions of
volume VI., parts 2 and 3, we ﬁnd that of the 4,485 persons apparently born at Rome, 3,723 (eighty-three percent) fall into the list which by our criteria
represents foreign extraction. This ﬁgure is probably not far from correct, but
I think it would be raised somewhat if it were possible to decide what proportion of Latin cognomina conceals slaves and liberti. For instance, a name like Q.
Manlius Restitutus (VI. 22,015) would usually pass with little suspicion. But the
inscription also names his father, mother, wife, and two sons, all of whom have
Greek cognomina. Because of his parentage I have classed him as of foreign
stock, but there are scores of brief inscriptions in which the necessary facts are
not provided. In these the subject had to be classed, however erroneously, as
Latin.
In order to reckon if possible the margin of error in cases like this, I have
attempted to test the respectability of Latin cognomina, but with rather unsatisfactory results. I counted all the names of slaves and freedmen in the indexes
of volumes V., IX., XIV., and over a thousand in volume VI., in order to get
a group of ﬁ ve thousand bearing the prevalent slave-names. More than half
(2,874) have Greek names, the most popular of these being Eros (58 times),
Pamphilus (36), Antiochus (34), Hermes (30), Alexander (28), Philomusus (26),
Onesimus (22), Philargyrus (21), names, most of which were also very popular
among free Greeks and Asiatics. Two thousand one hundred and twenty-six
have Latin names, some of which occur with remarkable frequency, e.g., Felix
(97), Hilarus –a (64-53), Faustus –a (58-33), Salvius –a (38-18), Fortunatus –a
(29-15), Primus –a (51-47), Secundus –a (25-34), Tertius –a (18-18), Auctus –a
(24-25), Vitalis (36), Januarius –a (22-6). Now, if we compare these Latin names
with those borne by better-class Roman plebeians, by the pretorian guards,
for instance (though many descendants of slaves served even in the pretorian
guards), we ﬁnd, despite a certain overlapping, quite a striking difference.
Apparently some names had acquired such sordid associations that they were
in general avoided by ordinary plebeians. The favorite names on the pretorian
lists are Maximus, Proculus, Severus, Verus, Capito, Justus, Celer, Marcellus,
Clemens, Victor, and the like. We may not say that any Latin name was conﬁ ned
wholly to slaves, nor would it be possible to give any usable list of relative
percentages, but we may at least say that the Romans recognized such names
as Salvius, Hilarus, Fortunatus, Optatus, Auctus, Vitalis, Januarius, as being
peculiarly appropriate to slaves; and Felix, Faustus, Primus, Primitivus, and
a few others must have cast some suspicion upon the bearer. After reviewing
in this light the seventeen percent of possible claimants of Latin origin in the
alphabetical list of inscriptions in volume VI., parts 2 and 3, I have little doubt
that a third of these would, with fuller evidence, be shifted into the class of
non-Latins.
On the other hand, the question has been raised whether a man with Greek
cognomen must invariably be of foreign stock. Could it not be that Greek
names became so popular that, like Biblical and classical names today, they
were accepted by Romans of native stock? In the last days of the empire this may have been the case;4 but the inscriptions prove that the Greek cognomen
was not in good repute. I have tested this matter by classifying all the instances
in the 13,900 inscriptions (there are 1,347) where the names of both the father
and son appear.5 From this it appears that fathers with Greek names are very
prone to give Latin names to their children, whereas the reverse is not true.
The statistics are as follows:
Greek cognomen Latin cognomen
Father 859 488
Son Greek Latin Greek Latin
460 399 53 435
This means that in one generation Greek names diminish from sixty-four
percent to thirty-eight percent, or that forty-six percent of the fathers with
Greek names give their sons Latin names, while only eleven percent of the
Latin fathers give their sons Greek names. And this eleven percent dwindles
upon examination into a negligible quantity. For instance, in seventeen of the
ﬁ fty-three cases the mother’s name is Greek, which betrays the true status of
the family; and in ten other instances the son’s gentile name differs from that of
the “father,” who is, therefore, probably a stepfather. In almost all of the other
twenty-six instances, the inscription is too brief to furnish a fair criterion for
judging. Clearly the Greek name was considered as a sign of dubious origin
among the Roman plebeians, and the freedman family that rose to any social
ambitions made short shrift of it. For these reasons, therefore, I consider that
the presence of a Greek name in the immediate family is good evidence that
the subject of the inscription is of servile or foreign stock. The conclusion of
our pros and cons must be that nearly ninety percent of the Roman-born folk
represented in the above-mentioned sepulchral inscriptions of CIL, volume
VI., parts 2 and 3, are of foreign extraction.
Who are these Romans of the new type and whence do they come? How
many are immigrants and how many are of servile extraction? Of what race
are they? Seneca happens to make a remark which is often quoted as proof
of extensive immigration to Rome. He writes to his mother in derision of
Rome:
Of this crowd the greater part have no country; from their own free towns
and colonies, in a word, from the whole globe, they are congregated.
Some are brought by ambition, some by the call of public duty, or by
reason of some mission, others by luxury which seeks a harbor rich and
commodious for vices, others by the eager pursuit of liberal studies,
others by shows, etc.6
Seneca apparently refers in large part to visitors, but also to immigrants.
In so far as he has transients in mind we are not concerned with the passage, for such people did little to affect the permanent racial complexion of Rome’s
civil population. A passage in Juvenal’s third satire is perhaps more to the
point, for he seems to imply that the Oriental has come to stay.
While every land…daily pours
Its starving myriads forth. Hither they come
To batten on the genial soil of Rome,
Minions, then lords of every princely dome,
Grammarian, painter, augur, rhetorician,
Rope-dancer, conjurer, ﬁ ddler, and physician.
This passage clearly suggests that foreigners of their own free will have
drifted to Rome in great numbers to make it their place of livelihood and their
permanent abode. I cannot here treat the whole problem, but, while agreeing
that the implication of this passage is true to a certain degree, I would question
whether the generalities in it are not too sweeping. It may well be that many
of the ex-slave rabble who spoke the languages of the East imposed upon the
uncritical by passing as free-born immigrants. Even freedmen were not beyond
pretending7
that they had voluntarily chosen slavery as a means of attaining to
Roman citizenship by way of the vindicta.At any rate, the Roman inscriptions
have very few records of free-born foreigners. Such men, unless they attained
to citizenship,8
ought to bear names like that in no. 17,171, Dis man. Epaeneti,
Epaeneti F. Ephesio, but there are not a dozen names of this sort to be found
among the inscriptions of volume VI., parts 2 and 3. Nor need we assume that
many persons of this kind are concealed among the inscriptions that bear the
tria nomina, for immigrants of this class did not often perform the services for
which the state granted citizenship. There could hardly have been an inﬂ ux
of foreign free-born laborers at Rome, for Rome was not an industrial city and
was more than well provided with poor citizens who could not compete with
slaves and had to live upon the state’s bounty. Indeed, an examination of the
laborious article by Kuhn9
fails to reveal any free-born foreigners among the
skilled laborers of the city. In regard to shop-keepers, merchants, and traders
we may refer to a careful discussion by Parvan.10 He has convincingly shown
that the retail trade was carried on at Rome, not by foreigners but by Romans
of the lower classes, mostly slaves and freedmen, and that while the provincials of Asia and Egypt continued throughout the empire to carry most of the
imports of the East to Rome, the Roman houses had charge of the wholesale
trade in the city. The free-born foreigner did not make any inroad upon this
ﬁ eld. However, in various arts and crafts, such as those mentioned by Juvenal,
the free immigrant could gain a livelihood at Rome. Some of the teachers of
rhetoric, philosophy, and mathematics, some of the doctors, sculptors, architects, painters, and the like, were citizens of the provincial cities who went to
Rome for greater remuneration. But even most of these professions were in
the hands of slaves and freedmen who had been given a specialized education
by their masters. In volume VI., part 2, which contains the sepulchral inscriptions classiﬁ ed according to arts and crafts, there is very little trace of the
free-born foreigner. Among the ﬁ fty inscriptions of medici, for instance, only
two, 9563, 9597, contain sure instances of such foreigners. Among the grammatici, rhetores, argentarii, structores, andpictores, where they might well be
expected, I ﬁ nd no clear case. It is evident then that the sweeping statements
of men like Juvenal and Seneca should not be made the basis for assuming a
considerable free-born immigration that permanently altered the citizen-body
of Rome. These writers apparently did not attempt to discriminate between
the various classes that were speaking foreign jargons on the streets of Rome.
As a matter of fact, this foreign-speaking population had, for the most part, it
seems, learned the languages they used within the city itself from slaves and
freedman parents of foreign birth.
If now this great crowd of the city was not of immigrant stock, but rather of
servile extraction, the family life of the slaves must have been far more conducive
to the propagation of that stock than is usually assumed, and, furthermore,
manumission must have been practiced so liberally that the slave-stock could
readily merge into the citizen-body. On the latter question our sources are
satisfactory; on the former, they have little to say. From Varro (II. i. 26 and x. 6)
and Columella (I. 8, 9) it has been well known that slaves on farms and pasturelands were expected to marry and have offspring. The Romans considered this
good economy, both because the stock of slaves increased thereby and because
the slaves themselves remained better satisﬁ ed with their condition. However,
partly because there exists no corresponding statement regarding slaves in the
city, partly because of a reckless remark made by Plutarch that Cato restricted
the cohabitation of his slaves, partly, too, because service in the city household
is supposed to have been very exacting, the prevalent opinion seems to be that
the marriage of slaves in the urban familia was unusual. Hence the statement is
frequently made that slavery died perforce when the pax Romana of the empire
put an end to capture by warfare.
Fortunately the columbaria of several Roman households provide a fairly
reliable record regarding the prevalence of marriage among city slaves. In CIL,
VI. 2, some 4,500 brief inscriptions are given, main1y from the rude funeral
urns of slaves and poor freedmen of the ﬁ rst century of the empire. About
one-third of these are from the columbaria of the Livii, Drusi, Marcelli, Statilii,
and Volusii, aristocratic households where, presumably, service would be as
exacting as anywhere, discipline as strict, and concern for proﬁ ts from the birth
of vernae as inconsiderable as anywhere. Furthermore, these inscriptions date
from a time when slaves were plentiful and the dearth of captives generally
assumed for a later day cannot be posited. Nevertheless, I believe that anyone
who will studiously compare the record of offspring in this group of inscriptions with that in ordinary plebeian inscriptions will reach the conclusion that
even in these households the slave doorkeepers and cooks and hairdressers
and scullery-maids customarily married and had children. The volume is full of interesting instances: Livia’s sarcinatrix married her mensor (VI. 3,988),
Octavia’s ornatrix was the wife of her keeper of the plate (5,539), Statilius’s
courier courted the spinning-maid of the household (6,342). In the lists of
husbands and wives one ﬁ nds a chef (7,458), a vestiarius (9,963), a vestiﬁ ca (5,206),
an unctor (6,381), a slave-maid serving as secretary a manu (9,540), the keeper
of my lady’s mirrors (7,297), of her handbag (7,368), of her wardrobe (4,043),
of her jewels (7,296), and what not. Now, these inscriptions are all extremely
brief. There are a great many like 4,478, Domitia Sex, l.Artemisia, Tertius, Viator,
where the word coniunx or contubernalis is probably, though not necessarily,
understood. Furthermore, the record of children is not as complete as it would
be in inscriptions of the better classes. A slave-child is, of course, not always
honored with a record of its brief existence. Moreover, slave families, not being
recognized in formal law, were sometimes broken up, so that some of the
names fail to appear with the rest of the family. Nevertheless, the proportion
of marriages and of offspring recorded by these very inscriptions, brief and
incomplete as they are, is remarkably large. In the thousands of inscriptions
of the columbaria of the Livii, Drusi, Marcelli, and the ﬁ rst eighty of the Volusii
(to make the even 1,000) I ﬁ nd,
151 inscriptions recording offspring.
99 additional inscriptions recording marriage.
152 additional inscriptions (like 4,478 quoted above) probably
recording marriage.
___
402
Now this is not, of course, as large a proportion as is found in the main
body of normal inscriptions. For comparison I give the proportions of 14,000
of volume VI., parts 2 and 3, reduced to the ratio of 1,000:
Per 1,000 Total
280 3,923 inscriptions recording offspring.
184 2,577 additional inscriptions recording marriage.
39 548 additional inscriptions probably recording
marriage.
____
503
Here, as we should expect, the proportion of children is larger, and the long
list of inscriptions bearing names of a man and a woman whose relationship
is not deﬁ ned yields in favor of a record of conjuges. But, as has been said, the
slave inscriptions are far briefer and less complete than the others.
To discover whether the lower proportion in the ﬁ rst list might be due to
the brevity of the inscriptions, I compared it with the list of 460 inscriptions of greater length, edited in volume VI., part 2, 8,639ff., as being ex familia Augusta.
These inscriptions are longer, to be sure, because the persons designated had
reached some degree of prosperity and could afford a few feet of sod with a
separate stone. But even these slaves and freedmen were generally required
to furnish close and persistent attention to their service. I have again given
the numbers in the proportion of 1,000 for the sake of comparison.
Per 1,000 Total
290 133 inscriptions recording offspring.
220 101 additional inscriptions recording marriage.
78 36 additional inscriptions probably recording
marriage.
____
588
From this list, if we may draw any conclusions from such small numbers,
it would appear that the imperial slaves and freedmen were more productive
than the ordinary citizens of Rome. And I see no reason for doubting that
the proportions in the households of the Livii, Drusi, etc., would be nearly as
large if the inscriptions were full lapidary ones, instead of the short notices
that were painted or cut upon the small space of an urn.
Finally, for the sake of getting a fuller record regarding the poorer classes,
I read 3,000 inscriptions of the miscellaneous columbaria that follow those of
the aristocratic households. These are nos. 4,881–7,881 of volume VI., part 2.
A very few of these inscriptions contain names of poor free-born citizens who
associated with—in fact were probably related to—slaves and ex-slaves, but
the proportion is so small that we may safely use this group for our present
purpose. Three thousand inscriptions from miscellaneous columbaria:
Per 1,000 Total
154 462 inscriptions recording offspring.
111 332 additional inscriptions recording marriage.
73 220 additional inscriptions probably
recording marriage.
____
338
This group, consisting of the very briefest inscriptions, set up by the poorest
of Rome’s menial slaves, shows, as we might expect, the smallest birth and
marriage rate. But when we compare it with that of the corresponding class
engaged in the aristocratic and imperial households, the ratios fall only in
proportion to the brevity and inadequacy of the record.

To sum up, then, it would seem that not only were the slaves of the
familia rustica permitted and encouraged to marry, as Varro and Columella
indicate, but—what the literary sources fail to tell—that slaves and freedmen
in the familia urbana did not differ from country slaves in this respect. And,
considering the poverty of those who raised these humble memorials, the
brevity of the records, and the ease with which members of such families
were separated, the ratio of offspring is strikingly large. We cannot be far
from wrong if we infer that the slaves and freedmen11 of the city were nearly
as proliﬁ c as the free-born population.
But however numerous the offspring of the servile class, unless the Romans
had been liberal in the practice of manumission, these people would not have
merged with the civil population. Now, literary and legal records present
abundant evidence of an unusual liberality in this practice at Rome, and the
facts need not be repeated after the full discussions of Wallon, Buckland,
Friedländer, Dill, Lemonnier, and Cicotti. If there were any doubt that the
laws passed in the early empire for the partial restriction of manumission did
not seriously check the practice, the statistics given at the beginning of the
paper would allay it. When from eighty to ninety percent of the urban-born
population proves to have been of servile extraction, we can only conclude
that manumission was not seriously restricted. I may add that a count of all the
slaves and freedmen in the familiae of the aristocratic households mentioned
above showed that almost a half were liberti. It is difﬁ cult to believe that this
proportion represents the usual practice, however, and, in fact, the ﬁ gures
must be used with caution. On the one hand, they may be too high, for many
who served as slaves all their lives were manumitted only in old age, and it
must also be recognized that slaves were less apt to be recorded than liberti.
On the other hand, the ﬁ gures may in some respects be too low, since there
can be little doubt that the designation liberti was at times omitted on the
simple urns, even though the subject had won his freedom. However, as far
as the inscriptions furnish deﬁ nite evidence, they tell the same tale as the
writers of Rome, namely, that slaves were at all times emancipated in great
numbers.
When we consider whence these slaves came and of what stock they
actually were, we may derive some aid from an essay by Bang, Die Herkunft der
Römischen, Sklaven. Bang has collected all the inscriptions like Damas, natione
Syrus, and C. Ducenius C. lib. natus in Syria, which reveal the provenance
of slaves. Of course, the number of inscriptions giving such information is
relatively small, a few hundred in all. It should also be noticed that when a
slave gives his nationality he shows a certain pride in it, which, in some cases
at least, implies that he is not a normal slave of the mart, born in servitude,
but rather a man of free birth who may have come into the trade by capture,
abduction, or some other special way. However, with this word of caution we
may use Bang’s statistics for what they are worth.

A very large proportion in his list (seven-eighths of those dating in our era)
came from within the boundaries of the empire. From this we may possibly infer
that war-captives were comparatively rare during the empire, and that, though
abduction and kidnapping supplied some of the trade, the large bulk of the
slaves were actually reared from slave-parents. Doubtless slaves were reared
with a view to proﬁ t in Greece and the Orient, as well as in Italy, and I see no
reason for supposing that the situation there differed much from that of our
Southern States where—for obvious economic reasons—the birth-rate of slaves
was higher between 1800 and 1860 than the birth-rate of their free descendants
has been since then. An examination of the names in Bang’s list with reference
to the provenance of the bearer will do something toward giving a criterion for
judging the source of Italian slaves not otherwise speciﬁ ed. In a very few cases
a name appears which is not Greek or Latin but Semitic, Celtic, etc., according
to the birthplace of the slave, as, for instance, Malchio, Zizas, Belatusa. Such
names are rare and never cause any difﬁ culty. Somewhat more numerous, and
equally clear of interpretation, are the generic names that explicitly give the race
of the bearer, like Syrus, Cappadox, Gallus, etc. In general, however, slaves have
Greek or Latin names, and here difﬁ culties arise, for it has by no means been
certain whether or not these names had so distinctively servile a connotation that
they might be applied indiscriminately to captives from the North and West,
as well as to the slaves of Italy and the East. Nevertheless, there seems to be a
fairly uniform practice which differentiated between Greek and Latin names
during the empire. Slaves from Greece, from Syria, from Asia Minor, including
the province of Asia, Phrygia, Caria, Lycia, Pamphylia, Cappadocia, Bithynia,
Paphlagonia, Galatia—that is, from regions where Greek was the language of
commerce—regularly bore Greek, rather than Latin, names. Slaves from the
North—from Germany to Dacia—as a rule bore Latin names. Presumably their
own barbaric names were difﬁ cult to pronounce and Greek ones seemed inappropriate. Slaves from Spain and Gaul bore Latin and Greek names in about
equal numbers. But here we must apparently discriminate. These provinces
were old and commerce had brought into them many Oriental slaves from the
market. It may be that the Greek names were applied mostly to slaves of Eastern
extraction. This I should judge to be the case at least with the following: Ephesia
(Bang, p. 239), Corinthus, Hyginus, Phoebus (his father’s name is Greek), Eros
(a Sevir Aug.), and Philocyrius (p. 240, Hübner reads Philo, Cyprius). In general
we may apply these criteria in trying in some measure to decide the provenance
of slaves in Italy whose nativity is not speciﬁ ed: bearers of Greek names are in
general from the East or descendants of Eastern slaves who have been in the
West; bearers of Latin names are partly captives of the North and West, partly,
as we have seen from our Roman lists, Easterners and descendants of Easterners
who have received Latin names from their masters.
Therefore, when the urban inscriptions show that seventy percent of the
city slaves and freedmen bear Greek names and that a large proportion of the children who have Latin names have parents of Greek names, this at once
implies that the East was the source of most of them, and with that inference
Bang’s conclusions entirely agree. In his list of slaves that specify their origin
as being outside of Italy (during the empire), by far the larger portion came
from the Orient, especially from Syria and the provinces of Asia Minor, with
some from Egypt and Africa (which for racial classiﬁ cation may be taken with
the Orient). Some are from Spain and Gaul, but a considerable proportion of
these came originally from the East. Very few slaves are recorded from the
Alpine and Danube provinces, while Germans rarely appear, except among the
imperial bodyguard. Bang remarks that Europeans were of greater service to
the empire as soldiers than as servants. This is largely true, but, as Strack has
commented,12 the more robust European war-captives were apt to be chosen
for the grueling work in the mines and in industry, and consequently they
have largely vanished from the records. Such slaves were probably also the
least productive of the class; and this, in turn, helps to explain the strikingly
Oriental aspect of the new population.
Up to this point we have dealt mainly with the inscriptions of the city.
But they, of course, do not represent the state of affairs in the empire at large.
Unfortunately, it is difﬁ cult to secure large enough groups of sepulchral inscriptions for other cities and districts to yield reliable average on the points just
discussed. However, since the urban inscriptions have presented a general
point of view regarding the proliﬁ cness of slaves and the signiﬁ cance of the
Greek cognomen, it will sufﬁ ce to record the proportion of servile and Oriental
names found in some typical district outside of the city. The proportion of Greek
names to Latin among the slaves and liberti of the city was, in the inscriptions
I recorded, seventy percent versus thirty percent. This is of course very high.
In CIL, volume XIV. (Latium outside of Rome), the index of cognomina gives
571 to 315, that is, about sixty-four percent to thirty-six percent; volume IX.
(Calabria to Picenum), 810 to 714, i.e.,ﬁ fty-three to forty-seven percent; volume
V. (Cisalpine Gaul), 701 to 831, i.e.,forty-six to ﬁ fty-four percent. This, in fact,
is the only part of Italy where the majority of slaves and freedmen recorded
did not bear Greek names. As is to be expected, northern slaves, who generally
received Latin names, were probably found in larger numbers here; but again
it should not be forgotten that a great many of the Latin-named slaves were of
Eastern extraction.
In order to get more speciﬁ c evidence regarding the nature of the population
in the West, free as well as servile, we may read the sepulchral inscriptions of
some typical towns13 and districts. I have listed them in four groups: (1) slaves
and freedmen bearing Latin names; (2) slaves and freedmen bearing Greek
names; (3) free-born citizens with Latin cognomen; (4) free-born citizens
with Greek cognomen. Under 3 and 4, I have, except when explicit evidence
proved the contrary, credited the tria nomina as indication of free birth; but
wish again to call attention to the caution contained in note 3. In cases of doubt the absence of the gentile name has been taken as an indication of
servile station if the name given is Greek or Latin and not Barbarian.
1 2 3 4 Sum
Marsi and Vestini, Italy.............. 201 119 234 58 612
Beneventum, Italy..................... 141 129 297 57 624
Milan and Patavium, North Italy.182 135 400 93 810
Narbo, Gaul...........................257 160 332 95 844
Gades, Corduba,
Hispalis, Emerita, Spain......... 129 101 305 90 625
______________________________________
910 644 1,568 393 3,515
When the indexes of CIL are nearer completionsuch details will be more
readily available and the tedious work of getting full statistics may be
undertaken with the hope of reaching some degree of ﬁ nality. However,
the trend is evident in what we have given, and the ﬁ gures are, I think,
fairly representative of the whole. In these towns, as at Rome, the proportion of non-Latin folk is strikingly large. Slaves, freedmen, and citizens of
Greek name make up more than half the population, despite the fact that
in the nature of the case these are presumably the people leastlikely to be
adequately represented in inscriptions. Furthermore, if the Latin names
of freedmen in half the instances conceal persons of Oriental parentage,
as they do in the city, the Easterner would be represented by classes 2
and 4, half of class 1, and a part of class 3. How strikingly un-Latin these
places must have appeared to those who saw the great crowd of humble
slaves, who were buried without ceremony or record in nameless trenches!
Yet here are the Marsi, proverbially the hardiest native stock of the Italian
mountains; Beneventum, one of Rome’s old frontier colonies; Milan and
Padua, that drew Latins and Romanized Celts from the richest agricultural
districts of the Po valley; the old colony of Narbo, the home of Caesar’s
famous Tenth Legion—the city that Cicero called specula populi Romani; and
four cities at the western end of the empire. If we may, as I think fair, infer
for these towns what we found to be true at Rome, namely, that slaves
were quite as proliﬁ c as the civil population, that they merged into the
latter, and that Greek names betokened Oriental stock, it is evident that
the wholeempire was a melting-pot and that the Oriental was always and
everywhere a very large part of the ore.
There are other questions that enter into the problem of change of race at
Rome, for the solution of which it is even more difﬁ cult to obtain statistics. For
instance, one asks, without hope of a sufﬁ cient answer, why the native stock
did not better hold its own. Yet there are at hand not a few reasons. We know for instance that when Italy had been devastated by Hannibal and a large part
of its population put to the sword, immense bodies of slaves were bought
up in the East to ﬁ ll the void; and that during the second century, when the
plantation system with its slave service was coming into vogue, the natives
were pushed out of the small farms and many disappeared to the provinces
of the ever-expanding empire. Thus, during the thirty years before Tiberius
Gracchus, the census statistics show no increase. During the ﬁ rst century B.C.,
the importation of captives and slaves continued, while the free-born citizens
were being wasted in the social, Sullan, and civil wars. Augustus afﬁ rms that he
had had half a million citizens under arms, one-eighth of Rome’s citizens, and
that the most vigorous part. During the early empire, twenty to thirty legions,
drawn of course from the best free stock, spent their twenty years of vigor in
garrison duty, while the slaves, exempt from such services, lived at home and
increased in number. In other words, the native stock was supported by less
than a normal birth-rate, whereas the stock of foreign extraction had not only
a fairly normal birth-rate but a liberal quota of manumissions to its advantage.
Various other factors, more difﬁ cult to estimate, enter into the problem of the
gradual attrition of the native stock. It seems clear, for instance, that the old
Indo-Germanic custom of “exposing” children never quite disappeared from
Rome. Law early restrained the practice and in the empire it was not permitted
to expose normal males, and at least the ﬁ rst female must be reared. It is impossible, however, to form any clear judgment from the literary sources as to the
extent of this practice during the empire. I thought that a count of the offspring
in a large number of inscriptions might throw light upon the question, and
found that of the 5,063 children noted in the 19,000 inscriptions read, 3,155, or
about 62.3 percent, were males. Perhaps this reﬂ ects the operation of the law
in question, and shows that the expositio of females was actually practiced to
some extent. But here too we must remember that the evidence is, by its very
nature, of little worth. Boys naturally had a better chance than girls to gain
some little distinction and were therefore more apt to leave a sepulchral record.
At any rate, if expositio was practiced, the inscriptions show little difference in
this respect between the children of slaves and freedmen and the children of
the ordinary city populace.14
But the existence of other forms of “race suicide,” so freely gossiped about
by writers of the empire, also enters into this question; and here the inscriptions
quite fail us. The importance of this consideration must, nevertheless, be kept
in mind. Doubtless, as Fustel de Coulanges (La Cité Antique) Antique) has remarked, it
could have been of little importance in the society of the republic so long as
the old orthodox faith in ancestral spirits survived, for the happiness of the
manes depended upon the survival of the family, and this religious incentive
probably played the same role in the propagation of the race as the Mosaic
injunctions among the Hebrews, which so impressed Tacitus in a more degenerate day of Rome. But religious considerations and customs—which in this matter emanate from the fundamental instincts that continue the race—were
questioned as all else was questioned before Augustus’s day. Then the process
of diminution began. The signiﬁ cance of this whole question lies in the fact that
“race suicide” then, as now, curtailed the stock of the more sophisticated, that
is, of the aristocracy and the rich, who were, to a large extent, the native stock.
Juvenal, satirist though he is, may be giving a fact of some social importance
when he writes that the poor bore all the burdens of family life, while the rich
remained childless:
jacet aurato vix ulla puerpera lecto;
Tantum artes hujus, tantum medicamina possunt,
Quae steriles facit.15
There may lie here—rare phenomenon—an historic parallel of some
meaning. The race of the human animal survives by means of instincts
that shaped themselves for that purpose long before rational control came
into play. Before our day it has only been at Greece and Rome that these
impulses have had to face the obstacle of sophistication. There at least the
instinct was beaten, and the race went under. The legislation of Augustus
and his successors, while aimed at preserving the native stock, was of the
myopic kind so usual in social law-making, and, failing to reckon with
the real nature of the problem involved, it utterly missed the mark. By
combining epigraphical and literary references, a fairly full history of
the noble families can be procured, and this reveals a startling inability
of such families to perpetuate themselves. We know, for instance, in
Caesar’s day of forty-ﬁ ve patricians, only one of whom is represented
by posterity when Hadrian came to power.16 The Aemilii, Fabii, Claudii,
Manlii, Valerii, and all the rest, with the exception of the Cornelii, have
disappeared. Augustus and Claudius raised twenty-ﬁ ve families to the
patriciate, and all but six of them disappear before Nerva’s reign. Of
the families of nearly four hundred senators recorded in 65 A.D. under
Nero, all trace of a half is lost by Nerva’s day, a generation later. And
the records are so full that these statistics may be assumed to represent
with a fair degree of accuracy the disappearance of the male stock of
the families in question. Of course members of the aristocracy were the
chief sufferers from the tyranny of the century, but this havoc was not
all wrought by delatores and assassins. The voluntary choice of childlessness accounts largely for the unparalleled condition. This is as far as the
records help upon this problem, which, despite the silence, is probably
the most important phase of the whole question of the change of race.
Be the causes what they may, the rapid decrease of the old aristocracy
and the native stock was clearly concomitant with a twofold increase
from below: by a more normal birth-rate of the poor, and the constant
manumission of slaves.

This Orientalizing of Rome’s populace has a more important bearing
than is usually accorded it upon the larger question of why the spirit and
acts of imperial Rome are totally different from those of the republic, if
indeed racial characteristics are not wholly a myth. There is today a healthy
activity in the study of the economic factors—unscientiﬁ c ﬁ nance, ﬁ scal
agriculture, inadequate support of industry and commerce, etc.—that
contributed to Rome’s decline. But what lay behind and constantly reacted
upon all such causes of Rome’s disintegration was, after all, to a considerable extent, the fact that the people who built Rome had given way to a
different race. The lack of energy and enterprise, the failure of foresight
and commonsense, the weakening of moral and political stamina, all were
concomitant with the gradual diminution of the stock which, during the
earlier days, had displayed these qualities. It would be wholly unfair to
pass judgment upon the native qualities of the Orientals without a further
study, or to accept the self-complacent slurs of the Romans, who, ignoring
certain imaginative and artistic qualities, chose only to see in them unprincipled and servile egoists. We may even admit that had the new races had
time to amalgamate and attain a political consciousness, a more brilliant
and versatile civilization might have come to birth. That, however, is not
the question. It is apparent that at least the political and moral qualities which
counted most in the building of the Italian federation, the army organization,
the provincial administrative system of the republic, were the qualities most
needed in holding the empire together. And however brilliant the endowment
of the new citizens, these qualities they lacked. The Trimalchios of the empire
were often shrewd and daring businessmen, but their ﬁ rst and obvious task
apparently was to climb by the ladder of quick proﬁ ts to a social position in
which their children with Romanized names could comfortably proceed to
forget their forebears. The possession of wealth did not, as in the republic,
suggest certain duties toward the commonwealth. Narcissus and Pallas might
besagacious politicians, but they were not expected to be statesmen concerned
with the continuity of the mos majorum. And when, on reading Tacitus, we are
amazed at the new servility of Scipios and Messalas, we must recall that these
scattered inheritors of the old aristocratic ideals had at their back only an alien
rabble of ex-slaves, to whom they would have appealed in vain for a return to
ancestral ideas of law and order. They had little choice between servility and
suicide, and not a few chose the latter.
It would be illuminating by way of illustration of this change to study the
spread of the mystery religions. Cumont seems to think that these cults won
many converts among all classes in the West. Toutain, skeptical on this point,
assigns not a little of the new religious activity to the rather formal inﬂ uence of
the court at Rome. Dobschütz, a more orthodox churchman, seems to see in the
spread of these cults the pervasion of a new and deeper religious spirit, which,
in some mystical way, was preparing the old world for Christianity. But is not the success of the cults in great measure an expression of the religious feelings
of the new people themselves? And if it is, may it not be that Occidentals who
are actually of Oriental extraction, men of more emotional nature, are simply
ﬁ nding in these cults the satisfaction that, after long deprivation, their temperaments naturally required? When a senator, digniﬁ ed by the name of M. Aurelius
Victor, is found among the votaries of Mithras in the later empire, it may well
be that he is the great-grandson of some child kidnapped in Parthia and sold
on the block at Rome. Toutain has proved, I think, that in the northern and
western provinces the only Oriental cult that took root at all among the real
natives was that of Magna Mater, and this goddess, whose cult was directed
by the urban priestly board, had had the advantage of centuries of a rather
accidental recognition by the Roman state. In the western provinces, the Syrian
and Egyptian gods were worshipped chieﬂ y by people who seem not to be
native to the soil. The Mithraic worshippers in these provinces were, for the
most part, soldiers recruited or formerly stationed in the East, and Orientals
who, by way of commerce or the slave-market, had come to live in the West.
From the centers where such people lived the cult spread but very slowly.
It would hardly be worth while to attempt any conclusion for the city
of Rome, since, as we have seen, the whole stock there had so changed that
fair comparisons would be well-nigh unattainable; but the Po valley,
that is Cisalpine Gaul, which preserved its Occidental aspect better than
any other part of Italy, might yield usable data. For this region nearly
one hundred devotees of Oriental gods are recorded in the ﬁ fth volume
of CIL, and, as soldiers and Roman ofﬁ cers are not numerous there,
the worshippers may be assumed to represent a normal average for the
community. Among them I ﬁ nd only twelve who are actually recorded
as slaves or freedmen, but upon examination of the names, more than
four-ﬁ fths seem, after all, to belong to foreign stock. Nearly half have
Greek names. Several are seviri Augustales, and, therefore, probably liberti;
and names like Publicius, Verna, Veronius (at Verona), tell the same tale.
Finally, there are several imperial gentile names—Claudius, Flavius,
Ulpius, Actius, etc.—which, when found among such people, suggest that the
Roman nomenclature is a recent acquisition. There is a residue of only some
twelve names the antecedents of which remain undeﬁ ned. This seems to me
to be a fairly typical situation, and not without signiﬁ cance. In short, the
mystery cults permeated the city, Italy, and the western provinces only to
such an extent as the city and Italy and the provinces were permeated by
the stock that had created those religions.
At Rome, Magna Mater was introduced for political reasons during
the Punic War, when the city was still Italian. The rites proved to be
shocking to the unemotional westerner, who worshipped the staid patrician
called Jupiter Optimus Maximus, and were locked in behind a wall. As
the urban populace began to change, however, new rites clamored for admittance, for, as a senator in Nero’s days says,17 “Nationes in familiis
habemus, quibus diversi ritus, externa sacra.” And as the populace enforced
their demands upon the emperor for panem et circenses, so they also secured
recognition for their externa sacra. One after another of the emperors gained
popularity with the rabble by erecting a shrine to some foreign Baal, or a
statue to Isis in his chapel, in much the same way that our cities are lining
their park drives with tributes to Garibaldi, Pulaski, and who knows what
-vitch. Finally, in the third and fourth centuries, when even the aristocracy at
Rome was almost completely foreign, these Eastern cults, rather than those
of old Rome, became the centers of “patrician” opposition to Christianity. In
other words, the western invasion of the mystery cults is hardly a miraculous
conversion of the even-tempered, practical-minded Indo-European to an
orgiastic emotionalism, foreign to his nature. These religions came with
their peoples, and in so far as they gained new converts, they attracted for
the most part people of Oriental extraction who had temporarily fallen
away from native ways in the western world. Christianity, which contained
enough Oriental mysticism to appeal to the vast herd of Easterners in the
West, and enough Hellenic sanity to captivate the rationalistic Westerner,
found, even if one reckons only with social forces, the most congenial soil
for growth in the conglomeration of Europeans, Asiatics, and Africans that
ﬁ lled the western Roman Empire in the second century.
This is but one illustration. But it is offered in the hope that a more
thorough study of the race question may be made in conjunction with
economic and political questions before any attempt is made ﬁ nally to
estimate the factors at work in the change of temper of imperial Rome.
ENDNOTES
1. CIL, vol. VI., parts 2, 3, 4.
2. Vol. VI., part 4, published in 1902, contains 2,512 additional inscriptions of this
class.
3. In epigraphical discussions one constantly meets with the statement that freedmen
were compelled to indicate their status by the designation lib. or l. and that therefore
the occurrence of the tria nomina without such designation is proof of free birth.
Unfortunate1y, this rule, if indeed it was one, was so fre quently broken, that it must be
employed with caution. There are hundreds of obvious exceptions where tria nomina
of respectable appearance impose upon the reader until at the end of the inscription
the dedicant’s designation of patronus or contubernalis or conlibertus betrays the real
status, e. g.,VI. 7,849, 14,550, 16,203, 17,562, 20,675, 20,682, 22,299, 22,606, 23,927, 23,989.
Again, numerous bearers of faultless tria nomina fall under strong presumption of being
freedmen because of some ofﬁ cial title like sevir or because their sons prove to being
to one of the city tribes; cf. X. 690, 4,620, 6,677; VI. 12,431, 14,045, 20,079. Finally, there
are many instances like 14,018. Here a man gives the name of a large family (all with
tria nomina) including children and a grandchild, but only the youngest, Caesonia M.
F. Prima, a child of seven months, bears the F which deﬁ nitely indicates free birth.
Apparently the other members of the family were not entitled to the designation.
Compare also 20,123, 20,339, 23,813. Since in cases of doubt I have been compelled to
credit bearers of Latin tria nomina to the native stock, it will appear that this group has
more than received full credit in the accompanying lists.
4. There are not enough datable inscriptions available to show whether the Greek
cognomen gained or lost respectability with time. Obviously it may in general be
assumed that most of the freedmen who bore the gentile name of Aelius and Aurelius
belong to a later date than the general group of those named Julius and Claudius.
If we may use this fact as a criterion we may decide that there was little difference
between the ﬁ rst and the second century in this matter, since the proportion of Greek
cognomina is about the same in the two groups.
5. It is difﬁ cult to secure usable statistics in the case of women, since their cognomina
may come from almost any relative or near friend. However, an examination of the
indexes of names will show that the Greek cognomen was relatively no more popular
among the women than among the men.
6. Ad Helviam, 6.
7. Petronius, 57.
8. This criterion fails of course after citizenship was given to the provincials in the
third century, but when Rome’s population was decreasing there probably was not
a heavy immigration.
9. De Opiﬁ cum Romanorum Condicione (1910).
10. Die Nationalität der Kauﬂ eute im Römischen Kaiserreich (1909).
11. We cannot suppose that most of the children belong to the period subsequent to
the liberation of the parents. Very many of the liberati recorded were emancipated in
old age, and throughout the empire manumission of slaves under 30 years of age was
discouraged (Buckland, Roman Law of Slavery, p. 542). In a large number of instances
the form and contents of the inscriptions show that slave-fathers after emancipation
paid the price for children and wife.
12. Historische Zeitschrift, CXII. 9.
13. In this list I have omitted imperial ofﬁ cials and soldiers, since they are not likely
to be natives of the place.
14. I have compared the respective ratios of the girls and boys of the Julii and
the Claudii with those of the Aelii and the Aurelii (who would in general date about a
century later) but found no appreciable difference in the percentage. A chronological
test seems to be unattainable.
15. VI. 594–596.
16. Stech, in Klio, Beiheft X., Am. Hist. Rev., vol. XXI.: 46.
17. Tacitus, Annales, XIV. 44.

Monday 29 April 2013

African Ancestry of the Italians

Uniparental Markers of Contemporary Italian Population Reveals Details on Its Pre-Roman Heritage

Francesca Brisighelli equal contributor,
Vanesa Álvarez-Iglesias,
Manuel Fondevila,
Alejandro Blanco-Verea,
Ángel Carracedo,
Vincenzo L. Pascali,
Cristian Capelli,
Antonio Salas

Abstract

Background

According to archaeological records and historical documentation, Italy has been a melting point for populations of different geographical and ethnic matrices. Although Italy has been a favorite subject for numerous population genetic studies, genetic patterns have never been analyzed comprehensively, including uniparental and autosomal markers throughout the country.

Methods/Principal Findings

A total of 583 individuals were sampled from across the Italian Peninsula, from ten distant (if homogeneous by language) ethnic communities — and from two linguistic isolates (Ladins, Grecani Salentini). All samples were first typed for the mitochondrial DNA (mtDNA) control region and selected coding region SNPs (mtSNPs). This data was pooled for analysis with 3,778 mtDNA control-region profiles collected from the literature. Secondly, a set of Y-chromosome SNPs and STRs were also analyzed in 479 individuals together with a panel of autosomal ancestry informative markers (AIMs) from 441 samples. The resulting genetic record reveals clines of genetic frequencies laid according to the latitude slant along continental Italy – probably generated by demographical events dating back to the Neolithic. The Ladins showed distinctive, if more recent structure. The Neolithic contribution was estimated for the Y-chromosome as 14.5% and for mtDNA as 10.5%. Y-chromosome data showed larger differentiation between North, Center and South than mtDNA. AIMs detected a minor sub-Saharan component; this is however higher than for other European non-Mediterranean populations. The same signal of sub-Saharan heritage was also evident in uniparental markers.

Conclusions/Significance

Italy shows patterns of molecular variation mirroring other European countries, although some heterogeneity exists based on different analysis and molecular markers. From North to South, Italy shows clinal patterns that were most likely modulated during Neolithic times.

Citation: Brisighelli F, Álvarez-Iglesias V, Fondevila M, Blanco-Verea A, Carracedo Á, et al. (2012) Uniparental Markers of Contemporary Italian Population Reveals Details on Its Pre-Roman Heritage. PLoS ONE 7(12): e50794. doi:10.1371/journal.pone.0050794

Editor: David Caramelli, University of Florence, Italy

Received: June 15, 2012; Accepted: October 24, 2012; Published: December 10, 2012

Copyright: © 2012 Brisighelli et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: The research leading to these results has received funding from the People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007–2013/under REA grant agreement number 290344, and the Ministerio de Ciencia e Innovación (SAF2008-02971 and SAF2011-26983)(AS). CC and FB were partially funded by the British Academy for the project “The Greeks in the West: the genetic legacy of the colonisation in South Italy and Sicily”. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Introduction

Italy has historically been a convenient destination for human populations migrating from Africa, the Middle East and European locations, in part due to the geomorphological characteristics of the Italian Peninsula [1]. These groups settled preferentially on the islands and coastal territories [1] 500,000 years ago (ya), that is, along the Lower Paleolithic, the longest period of human prehistory, which was dominated by the notable diffusion of tools made from flaked stone [2]. Although rich in tools and animal bones, only some of these sites have provided a small quantity of human skeletal remains resembling those from the more recent sites of the Middle Paleolithic, dating to the Riss-Würm interglacial period and part of the succeeding Würm glaciation (circa 120,000 to 36,000 ya). These bones belong to a species named Homo sapiens neanderthalensis. [2] In this long Paleolithic period, navigation across the Mediterranean was probably rare and some present-day islands were accessible across land bridges later covered by the rising sea [3]. During the Upper Paleolithic, from 36,000 to 10,000 ya, the icecap expansion of the Late Glacial Maximum (LGM) pushed southward groups of hunters living in Central European areas [1], and the Neanderthals gave way to the present species of man Homo sapiens sapiens during the final phases of the Würm glaciation. The numerous traces from this period are particularly rich in burials, animal bones and tools, the latter having been worked with increased precision [2]. In the few thousand years of the following Mesolithic period (circa 10,000 to 6,000 ya) the climate continued to grow milder and sites from this period have been found throughout the entire Italian peninsula, being along the coasts in the plains and on the mountains. With the Neolithic period, from circa 6,000 BC to 2,800 BC, the traditional hunting and gathering economy was replaced by the introduction of agriculture, stock rearing, weaving and pottery. This new cultural influence came particularly from the Eastern Mediterranean and the Near East. Using the pottery production above all, it has been possible to reconstruct fairly accurately the various phases of this complex period [2]. During the Copper, Bronze and Iron ages, numerous population movements occurred between the Mediterranean basin and the Middle East [4]. Exchange of metals would determine the transformation of the first social organizations in ancient civilizations [4]. Sardinia, Sicily and Tuscany were among the first Italian territories to be occupied by humans due to their strategic location and the presence in their territories of important metal resources [5].

Different cultures, recognized on the basis of different archeological findings, settlements and burial traditions, arose in the period between the Mesolithic and Iron Age. Before the Roman conquest, ancient Italy was characterized only by the presence of Indo-European populations[6] living in the Italian Peninsula since the second millennium BC, corresponding to the period between the Iron Age and Romanization [2]. During all this period there were also increasing contacts with the Phoenician and Greek colonists: the former being largely present on the coasts of Sardinia and western Sicily and the latter in Southern Italy. These colonies had a considerable influence on the development of local cultures (from the Picenian to Campano-Samnite and the Apulian to Bruttio-Lucanian) [5].

The record of all the populations that inhabited the Italian territory during (pre)-history is incomplete; many records were of uncertain location and/or ambiguous denomination [6]. At the beginning of the first millennium BC the following native tribes could be distinguished on the Italian territory: the Ligures, on the coast that bears their name, in the northern Apennine valleys, part of the pre-alpine valleys and the western Po Valley; the Sicani, in the interior of Sicily; and the Itali, in present-day Calabria (from whom comes the name ‘Italy’, which was to be extended to all the territory of the peninsula). Besides the already mentioned Terramare tribe, on the southern edge of the Po Valley, and the Villanovans, probably from Eastern Europe who settled throughout Central Italy, there were also the Umbrians to the east of the upper basin of the Tiber. The Veneti, who occupied the territory that still bears their name, originally came from Illyria as did the Messapii (now modern Salento or South Apulia) and Iapyges, who settled in present-day Puglia (Apulia) [5]. Many other populations of Central-Southern Italy were created by the mixing of local and foreign elements dating back to the previous millennium; it is the case of the Sabines and Latini who settled in Lazio together with Falisci, Aequi, Volsci, Hernici and Ausones. The interior of Abruzzo was dominated by the Vestini, Paeligni and Marsi, while the central Adriatic coast was populated by Picentes, Marrucini and Frentani. The Apennine area of Molise and Basilicata was peopled by the Samnites and Lucanians. In Calabria and Sicily there were also the Bruttii and Siculi.

The Phoenician colonization of the coasts of the Western Mediterranean were mainly limited in Italy to Sardinia and western Sicily and preceded that of the Greeks. It was followed by Punic settlements (Trapani, Palermo, Cagliari) linked to the ancient Phoenician colony of Carthage.

At the time of the Roman Empire, at least two non-Indo-European populations still inhabited Italy, namely, the Ligures, in the northwestern area, and the Etruscans with settlements located in areas far from the Etruria (Tuscany and High Latium), such as the Po Plain and the coast of Campania. At the same time, Sardinia experienced the flourishing of a non-Indo-European Nuragic civilization and, then, the Phoenician colonization.

Genetics alone cannot disentangle the extremely complex demography of Italy through history. Some demographic movements have however left signals on uniparental and nuclear markers. Most of the genetic studies targeted local, e.g. [7], or regional, e.g. [8]–[11], Italian populations.

For the Y-chromosome, some attempts have been undertaken to analyze Italian variation to a more general scale [12]–[14]. Many studies have analyzed specific haplogroups in the Y-chromosomes, e.g. [15], [16], or the mtDNA, e.g. [8], [9]. In general, the different studies indicate that the genetic structure of the present Italian population seems to reflect, at least in part, the ethnic stratification of pre-Roman times [14]. Studies carried out in the past appear to show a major North–South cline consistent with archaeological estimates of two distinct processes: the first colonization of the area during the Paleolithic period and the subsequent Neolithic expansion from the Middle East after the last glacial [14]. There is some correspondence between patterns of variation at the Y-chromosome and geography. Thus, northern Italy shows similar frequencies as the haplogroups of Central Europe, with prevalence of the western R1-M173 haplogroup compare to the eastern I-M170. In the North, E3b1-M35 and J2-M172 show low frequencies but are more prevalent in the South, which has been interpreted to be a signal of the gene flow coming from Central European Neolithic farmers [17]. R1a1-M17 is rather rare, both in the North, where it probably originates from eastern Europe, and in the South, of possible Greek provenience [17]. Occurrence of J2-M172 Y-chromosomes in Tuscany has been related to the Etruscan heritage of the region (see [17]). The two Italian major islands, Sicily and Sardinia, show a different demographic history. The Y-chromosome variability of Sicily shares a common history with that of southern Italy, enriched by an additional Arab contribution, but also North African and Greek influences [18]. On the other hand, Sardinia has been considered to be a genetic outlier within Europe showing clear signals of founder effects; some scholars suggest that its peoples could be of ancient Iberian origin[19]; recent genetic studies point to genetic contribution coming from southern France [20].

On the other hand, mitochondrial DNA studies show that Italy does not differ too much from other European populations; however, some populations have the same peculiarities and preserve signals of the ancient past demographic event, such as the Tuscans [8], [9], or the Ladins [7], [21], [22]. Recently, patterns of variation observed in haplogroup U5b3 demonstrated for the first time the existence of a North Italian pre-historical human refuge from the hostile Central European regions covered by the ice of the Last Glacial Maximum period [20]; this area, as was also the Franco-Cantabrian region [23]–[26], served as a region of European repopulation during the beginning of the Holocene.

The main aim of the present study was comprehensively to analyze the patterns of mtDNA and Y-chromosome variation in Italy. This study differs from previous ones in that: (1) it provides mtDNA data from 12 new sample populations from Italy; (2) we analyzed two linguistic isolates, Ladin and Grecani Salentini, the latter sampled for the first time in this study; (3) we analyzed a sample population from Lucera (Southern Italy) for the first time, a population that according to documentation received an important input of North African immigrants during the thirteenth century; (4) we analyzed the patterns of mtDNA variation in Italy globally, that is, by combining more than 3,700 control region profiles from the literature (41 population samples in total) coupled with the more than 580 new profiles provided here; (5) Y-chromosome haplotype and haplogroup patterns are analyzed in parallel with the mtDNA data in order to determine the possible differences that occurred historically in the male versus female demographic movements; and (6) the influx of migrants from Africa (North and sub-Saharan) and other regions is also analyzed using phylogeographic inferences, and also a model of admixture based on haplotypic data and a panel of ancestry informative markers (AIMs).

Materials and Methods

Ethics statement

Written informed consent was obtained from all sample donors. Analysis of mtDNA sequences was approved by the institutional review boards of the Università Cattolica del Sacro Cuore (Roma). Moreover, the study conforms to the Spanish Law for Biomedical Research (Law 14/2007- 3 of July).

Samples

A total of 583 individuals were sampled from along the Italian Peninsula, representing 12 different populations (Figure 1), two of them (Ladin and Grecani Salentini) being linguistic isolates, and the Lucera being a historical enclave of Arabs coming from North Africa. A brief description of these latter three populations is given below.

Figure 1. Map showing the location of the samples analyzed in the present study and those collected from the literature (see Table 1).

Pie charts on the left display the distribution of mtDNA haplogroup frequencies, and those on the right the Y-chromosome haplogroup frequencies.

doi:10.1371/journal.pone.0050794.g001

In the Italian territory, the Alpine arc represents one of the main areas of presence of alloglot populations, some of them biologically isolated for historical and geographic reasons [27]. At the end of the medieval period (~1200 AD) and especially in the valley zone, a first colonization of native peasants began, starting with the use of lands previously exploited only for pasture and the lumber. Successively, with different modalities and under the control of laic and ecclesiastical owners, the colonization process involved migrant nuclei from the Tyrol, Carinthian area and other zones [28]. Currently, the Alpine arc populations are differentiated with a remarkable cultural diversity that is well represented by linguistic elements. Thus, besides the official main languages, numerous minority languages or dialects are also the cultural patrimony of linguistic minorities [27], [29]. Ladin is often attributed to be a relic of vulgar Latin dialects associated with Rhaeto-Romance languages. In the vast multi-ethnic Holy Roman Empire, and then after 1804 the Austrian empire, the Ladins were left in relative peace and were allowed to continue the use of their language and culture.

Grecani Salentini is a Hellenic-speaking linguistic island of Salento, situated in southern Puglia, and consisting of nine municipalities in which a neo-Greek dialect, also known as Grecanic or Griko, is spoken. The origins of this linguistic island in Salentine Greece are uncertain. The German linguist G. Rohlfs proposed its origin in the Magna Graecia region; while O. Parlangeli suggests a Byzantine derivation of the Griki of Salento. Greek researchers (e.g. A. Karanastasis) claim the input of Byzantine elements in the pre-existing Magna Graeciamatrix. The Greek arrival in the Salentine Peninsula occurred both in the Magna Graecia, and posterior Byzantine dominations. The numerous villages of Grecani Salentini had a Greek culture and language and practiced the Greek-orthodox religion. In the beginning of the Norman conquest (eleventh century), and more intensively with the arrival of different casati (clans) (Svevian, Angioin, Aragones, etc), the catholic clergy supplanted those of the orthodox faith[30].

The Lucera population has received an important influx from North African Arab peoples (see[31]). Thus, after the collapse of the Roman Empire in Europe, the Arab domination spread into the Mediterranean Basin. Referred to either as Moors in Iberia or Saracens in Southern Italy and Sicily, Arabs arrived in Europe in 711 AD, and in 831 AD Iberia and Sicily were almost completely subjected to Arab domination [31]. In the thirteenth century, Frederick II moved the Sicilian Arabs to the city of Lucera (North Apulia) [32]. This sample was genotyped for STRs and Y-chromosome SNPs in Capelli et al. [31]

To the best of our knowledge, all individuals collected in the present study were not maternally and paternally closely related; they had different surnames and all the donors referred back at least two generations in the region where the samples were collected.

All the samples were analyzed for the control region and selected mtSNPs (see below). A subset of the samples comprised unrelated males (n = 292) representing seven different populations. These samples were genotyped for a panel of 17 Y-chromosome SNPs (see below), and were previously genotyped for the Yfiler [33]. In addition, autosomal ancestry informative markers (AIMs) were genotyped in 441 individuals (see below).

DNA extraction

Blood extraction was performed with a salting-out method [34], modified and re-adapted to buccal cells. Swabs were incubated in 500 µl of 0.2 sodium acetate, 35 µl of 10% SDS and 20 µl of 20 mg/ml Proteinase K for 16 hours at 56°C. They were then removed and 500 µl of 3 M NaCl solution was added. Proteins were removed by centrifugation, and the DNA precipitated by adding 1 ml of ethanol 100% at −20°C for a few hours. After centrifugation, the DNA pellet was twice washed with ethanol 70%, dried and re-suspended in water. For the blood samples, aliquots of 500 µl each were thawed and red cells selectively lysed by a 1× lysis buffer. After three washes with the lysis buffer, white cells were pelleted and the DNA extracted using the salting-out protocol. All the samples were quantified by direct comparison with standard on agarose 1% minigels (1 g of agarose in 100 ml of TBE 1X- from the 1:10 diluition of TBE 10X).

PCR and mtDNA control region sequencing

MtDNA has been sequenced for the complete control region, from position 16024 (in HVS-I) to 569 (in HVS-II). The first and second hypervariable regions (HVS-I/II) were amplified via the polymerase chain reaction (PCR) and using primers reported by Álvarez-Iglesias et al. [35].

PCR was carried out in a 25 µl reaction mix with 1× reaction buffer (20 mM Tris-HCl, ph 8.0, 0.1 mM EDTA, 1 mM DDT, 50% (v/v) glycerol), 1.5 mM MgCl₂, 200 mM each dNTP, 0.4 µM each primer, 2.5 U (Units). Taq polymerase and 0.1–1 ng DNA template was added to the reaction mixture (Taq DNA Polymerase, recombinant. INVITROGEN® Corporation). Amplification was carried out in a GENE AMP® PCR SYSTEM 9700 (Applied Biosystems, Foster City, California,U.S.A.) using a hot start at 95°C for 1 min, followed by 36 cycles at 95°C for 30 sec, 55°C for 60 sec, and 72°C for 30 sec and a final extension at 72°C for 15 min. Before the sequencing reaction, PCR products were checked by electrophoresis in polyacrylamide non-denaturing gel (T9, C5), and subsequently the gel was stained with silver nitrate. PCR products were then purified with a MultiScreen® PCR_μ96 Plate (Millipore, Bedford, Ma 01730, U.S.A), 96-well device.The vacuum-based, size exclusion separation effectively and quickly removed the containing salts, unincorporated dNTPs and primers from PCR reactions. Cycle sequencing was performed on both strands in a GENE AMP® PCR SYSTEM 9700 (AB) thermal cycler using the ABI Prism® dRhodamine Terminator Cycle Sequencing Ready Reaction Kit (AB). This kit consists of a reaction mix composed of: DNA-modified and termostable polymerase, Buffer Tris-HCl (pH 9.0), MgCl₂, dNTPs, dichlororhodamine-marked ddNTPs. An aliquote of 30 ng amplicon and 3.2 ρM primers were added to a 2 µl reaction mix. Sequencing was carried out using a hot start at 96°C for 4 min, followed by 36 cycles at 96°C for 15 sec, 50°C for 10 sec, 60°C for 2 sec and a final extension at 60°C for 10 min. The removal of excess dideoxy terminators, primers and buffer was accomplished with an alcoholic purification.

The sequence products were denatured with deionized formamide and analyzed by capillary electrophoresis on an ABI PRISM 3130® Genetic Analyzer (AB).The resulting data were analyzed with PE/ABD software Sequencing Analysis 5.2 and sequences were aligned and compared with the Cambridge sequence [36] from position 16024 to16569 for HVS-I and from position 1 to 600 for HVS-II by the SeqScape v.2.0 (AB).

Analysis of mtDNA coding region SNPs

Biallelic markers were genotyped using a multiplex approach [37]. The selected SNPs were combined into two multiplex reactions. Multiplex 1 included a selection of SNPs defining common European haplogroups [38]. Multiplex 2 included exclusively polymorphisms defining sub-lineages inside haplogroup H. Primers were designed in order to adjust the annealing temperatures and amplicon lengths to allow analysis in multiplex reactions [37]. The sizes of the PCR products ranged from 80 to 224 bp.

Both multiplexes were performed using 10 ng of DNA template in a 25 µl reaction volume comprising 1× Taq Gold Buffer (AB), 200 µM of each dNTP, 2 mM MgCl₂ and 0.5 U of AmpliTaq Gold Polymerase (AB). For the primer concentrations, see [37].

Amplification was carried out using a GENE AMP® PCR SYSTEM 9700 (AB) thermocycler. After a 95°C pre-incubation step for 11 min, PCR was performed for a total of 32 cycles using the following conditions: 94°C denaturation for 30 sec, annealing at 60°C for 30 sec and extension at 72°C for 1 min, followed by a 15 min final extension at 72°C. PCR products were checked by polyacrylamide gel electrophoresis (T9, C5) visualized by silver staining.

After amplification, PCR products required purification to remove primers and unincorporated dNTPs. Post-PCR purification was performed with ExoSapIT (Amershan Pharmacia Biotech): 1 µl of PCR product was incubated with 0.5 µl of ExoSapIT for 15 min at 37°C followed by 15 min at 80°C for enzyme inactivation. The minisequencing reaction was performed in a GENE AMP® PCR SYSTEM 9700 (AB) thermocycler following the recommendations of the manufacturer: 2 µl of SNaPshot ready reaction mix, 0.2 µM of extension primer for each SNP (see [37]) and 1 µl of both purified PCR products in a total volume of 7 µl. The reaction mixture was subjected to 25 single base extension cycles of denaturation at 96°C for 10 sec, annealing at 50°C for 5 sec and with an extension at 60°C during 30 sec. After minisequencing reactions, a post-extension treatment to remove the 5′-phosphoryl group of ddNTPs aided the prevention of co-migration of unincorporated ddNTPs with extended primers and production of a high background signal. The final volume (7 µl) was treated with 0.7 µl of SAP (Amersham Biosciences) for 60 min at 37°C, followed by 15 min at 80°C for enzyme inactivation.

The minisequencing products (1.5 µl) were mixed with 10 µl of HiDi™ formamide and 0.2 µl of GeneScan-120 LIZ size standard (AB) and electroforesis was performed on an ABI PRISM 3130® Genetic Analyser (AB). The resulting data was analyzed with Gene Mapper ID.

Minisequencing of SNPs characterizing additional typical European haplogroups

Samples that were determined (using the SNP panel above) as being derived from J/T (T14766C; C7028T; T4216C), U (T14766C; C7028T; A12308G) and the U-subclade K (T14766C; C7028T; A12308G; A10398G), were further genotyped using an additional set of 14 haplogroup-specific SNP markers that identify the following sub-branches: J1 (G3010A), J1b (G3010A; C13879T), J1c (G3010A; C114798T), J2 (G15257A), T2a (A14687G), T2b (G5147A), U5a (A14793G), U5a1 (A14793G; A15218G), U5b (A7768G), U5b1 (A7768G; A5656G), U5b2 (A7768G; C1721T), K1 (T14798C; T1189C), K1a (T14798C; T1189C; C0497T) and K2 (T14798C; T1189C; T9716C). PCR and minisequencing reactions were performed as described above. For PCR and minisequencing primer concentrations, see Table S1.

Genotyping of Y-SNPs

Biallelic markers were genotyped using a multiplex approach [39]. A set of 30 SNPs was tested, allowing assignation of the analyzed Y-chromosome to haplogroups (Hg), following the nomenclature and the phylogenetic relationships defined from the Y Chromosome Consortium[40]. The selected method for allele discrimination was a single base extension reaction using the SNaPshot multiplex kit (AB). We added the M269 marker to the first of the four multiplexes, in order better to dissect the sub-haplogroup R1b (R1b3). The primers of this marker were M269-F 5′-TCA TGC CTA GCC TCA TTC CT-3′ and M269-R 5′-TCT TTT GTG TGC CTT CTG AGG-3′, and the minisequencing primer 5′-GGA ATG ATC AGG GTT TGG TTA AT-3′.

Genotyping of AIMs

A panel of 52 AIMs were genotyped according to Sánchez et al. [41] in a subset of 441 individuals. Several other population datasets were used for inter-population comparisons. This data corresponded to the CEPH panel (http://www.cephb.fr/en/cephdb/) as reported in HapMap (http://hapmap.ncbi.nlm.nih.gov/) and was collected using the data-mining tool SPSmart [42],[43]; it includes population samples from all over the world (Africa, Europe, Asia, etc.); see legend of Figure 2 for more information.

Figure 2. Analysis of AIMs in Italian populations versus other continental population groups.

(A) PCA of Italian populations divided into the main regions North, Center and South (as analyzed in the present study) and other European populations; (B) the same Italian populations plus sub-Saharan African, and Asian populations; (C) triangle plot as obtained using STRUCTURE analysis of Italian, European, sub-Saharan, and Asian populations; (D) bar plot of ancestral membership values as obtained using STRUCTURE analysis of the same populations used in (C). Population codes: 1: Angola; 2: Kenya-Bantu NE; 3: Mozambique; 4: Namibia-San; 5: Nigeria-Yoruba; 6: Senegal-Mandenka; 7: South Africa-Bantu; 8: Uganda; 9: Britain; 10: Denmark; 11: French; 12: Germany; 13: Ireland; 14*: NW Spain; 15*: Portugal; 16: Slovenia; 17: China-Dai; 18: China-Daru; 19: China-Han; 20: China-Hezhen; 21: Japanese; 22: Mongolia; 23: Taiwan; 24: Thailand. Genotypes were downloaded using the method in[43], [83] and belong to the CEPH panel. An asterisk indicates Mediterranean populations.

doi:10.1371/journal.pone.0050794.g002

Statistical analysis

A total of 42 Italian population samples were analyzed for mtDNA in the present study. Comparative inter-population analyses were also carried out for the HVS-I segment ranging from 16024 to 16365, since this is the analyzed segment common to all of them. Haplotype (H) and nucleotide diversity (π) and other diversity indices [44]–[46] were computed using DnaSP 4.10.3 software [47]. Problematic variation located around 16189, usually associated to length heteroplasmy e.g. 16182C or 16183C, was ignored. Analysis of molecular variance (AMOVA) was carried out using Arlequin 3.5. [48]. Nomenclature of mtDNA lineages followed previous studies e.g. [23], [25], [38], [49], [50]; see Phylotree for a compilation of the worldwide phylogeny and an update of the nomenclature based on entire mtDNA genomes [51]. Genotyping and documentation errors were monitored following the phylpogenetic principles previously applied e.g. [52]–[59].

Mitochondrial DNA and Y-chromosome data was collected from the literature. The mtDNA data generated in the present study was analyzed together with 3,834 mtDNA HVS-I Italian profiles collected from the literature (Table S2; 76 sample populations). The Y-SNPs were analyzed together with 1,251 Italian profiles reported in the literature (16 population samples). A full list of references for all the data used in the present study is given in Table S2.

Haplogroup frequencies were estimated by chromosome counting. Statistical differences in haplogroup frequencies were evaluated using a Pearson's chi- square test and by setting up the nominal significant value α as 0.05.

Finally, classification of mtDNA sequences into haplogroups was performed following phylogenetic criteria (Phylotree Build 14, http://www.phylotree.org/) and using both the control region sequence profile and mtSNPs.

Results

Molecular diversity of mtDNA and Y-chromosome Italian profiles

Diversity indices were computed for all the populations analyzed in the present study and also in those Italian populations samples reported in the literature (Tables 1 and 2). Population samples were also grouped in main regions (North, Central, South, West, and East) in order to investigate the role of geography in the distribution of mtDNA variation.

Table 1. Diversity indices computed for different Italian regions based on HVS-I data (sequence segment 16090–16365).

doi:10.1371/journal.pone.0050794.t001

Table 2. Diversity indices computed for different Italian regions based on Y-SNPs.

doi:10.1371/journal.pone.0050794.t002

Mitochondrial DNA haplotypes for the samples analyzed in the present study are reported inTable S3. Table 1 shows the molecular diversity values based on mtDNA data for 41 Italian population samples. The values indicate that the Isle of Elba is, by far, the Italian population sample that shows the lowest diversity for all the indices computed, probably as a consequence of its relative isolation from the country. It has been reported that this was a well-known enclave of Etruscan influence, and some mtDNA particularities have been described before [8], [9]. Alternatively, low molecular diversity could be due to low sample sizes, although this fact is mirrored in the standard deviation of the different estimates. Excluding the Isle of Elba, haplotype diversity in Italy ranges from 0.834 to 1, nucleotide diversity from 0.01003 to 0.02409, and the average value of nucleotide differences from 3.4 to 8.19 (a value that is correlated with the nucleotide diversity). In general, Italy shows some level of heterogeneity when examined for diversity values.

When grouping populations by main geographical regions, it can be observed that Central Italy has slightly lower values than North and South Italy for all the indices computed (Table 1). The higher diversity values were found in South Italy. Diversity values are however very similar when examining populations located in West Italy versus those in the East. The inclusion of Sicily (as part of South Italy) in the computation does not substantially change these estimates (Table 1).

Y-SNP data were obtained for all the samples analyzed in the present study (Table S4). Table 2 shows the diversity indices for the Y-SNPs in different Italian populations. The Y-STR diversity values for the samples analyzed in the present study and other Italian and European samples have already been reported in Brisighelli et al. [33]. As expected, diversity values of Y-SNP haplogroup patterns are lower than those obtained for the mtDNA haplotypes given that the indices are based on haplogroup and not on Y-STR haplotypes. In fact, values based on Y-STR profiles (minimum or extended Yfiler profiles) [33] are higher than those observed for the HVS-I profiles. Ladins are among the populations with the lowest Y-SNP diversity values, while the Grecani Salentini show diversity values that are comparable to other Italian samples. Modena shows remarkable low haplotype diversity values.

Phylogeography

The mtDNA haplogroup make-up of Italy as observed in our samples fits well with expectations in a typical European population. Thus, most of the Italian mtDNAs (~89%) could be attributed to European haplogroups H (~40%), I (~3%), J (~9%), T (~11%), U (~20%; U minus U6), V (~3%), X (~2%) and W (~1%); Figure 1. There are however important differences in haplogroup frequencies when examining them by main geographical regions. Thus, for instance, haplogroup H is 59% in the North, 46% in the Center, and decays to ~33% in the South; moreover, these regional differences are statistically significant: North vs South (Pearson's chi-square, unadjusted-P value<0.00003), and Center vs South (Pearson's chi-square, unadjusted-P value<0.03724).

Mitochondrial DNA haplotypes of African origin are mainly represented by haplogroups M1 (0.3%), U6 (0.8%) and L (1.2%); from here onwards, L will be used to refer to all mtDNA lineages, excluding the non-African branches N and M [60], [61].

A total of 282 Y-chromosomes were analyzed for a set of Y-SNPs and were classified into 22 different haplogroups (Figure 3). Two haplogroups were not found, even though markers defining these clades were tested: N3 and R1a1. Five haplogroups represented 76.71% of the total chromosomes: R1b3, J2, I(xI1b2), E3b1 and G. The frequencies averaged across populations were 26%, 21.2%, 10.2%, 9.9% and 9.2%, respectively. The remaining haplogroups sum to 23.2% in the total sample, and never above 4% in single population samples.

Figure 3. Phylogeny of Y-chromosome SNPs and haplogroup frequencies in different Italian populations.

doi:10.1371/journal.pone.0050794.g003

R1b3 frequency was found to be higher in the northern part of the country, while the Y-chromosome haplogroups G and E3b1, J2 and I(xI1b2)frequencies were higher in the south and in the central part of the country, respectively (Figure 1).

Regional differences are substantially higher in the Y-chromosome than in the mtDNA. Thus, for instance, haplogroup R in the Y-chromosome was 54% in the North, 18% in the Center, and 31% in the South. Frequency differences were statistically significant between North vs Center (Pearson's chi-square, unadjusted-P value = 0.0014), and North vs South (Pearson's chi-square, unadjusted-P value<0.00004). Haplogroup J2 also revealed important regional differences; it added to 9% in the North, 37% in the Center, and 22% in the South, with statistically significant differences between the North vs Center (Pearson's chi-square, unadjusted-P value<0.00002), North vs South (Pearson's chi-square, unadjusted-Pvalue<0.00148), and in the limit of significance Center vs South (Pearson's chi-square, unadjusted-P value<0.049).

Autosomal ancestry in Italy

A panel of 52 AIMs was genotyped in 435 Italian individuals in order to estimate the proportion of ancestry from a three-way differentiation: sub-Saharan Africa, Europe and Asia. Structure analyses allowed us to infer membership proportions in population samples, and these proportions can be graphically displayed, as in Figure 2. This analysis indicated that Italians have a basal proportion of sub-Saharan ancestry that is higher (9.2%, on average) than other central or northern European populations (1.5%, on average). The amount of African ancestry in Italians is however more comparable to (but slightly higher than) the average in other Mediterranean countries (7.1%). Figure 2 shows in a triangle plot the relationships of Italians compared to other European, African and Asian populations.

PCA observations confirmed the results from Structure analysis, clustering Italian profiles tightly with other European ones. Thus, PCA indicated that North, Central and South Italy do not show differences between them, nor from other European populations (Figure 2). PCA also indicated clear-cut differences between Italians, Africans and Asians (Figure 2).

AMOVA

AMOVA analyses were carried out following different grouping schemes. The samples were pooled into a single population, but also by considering main Italian regions. Analyses were carried out over haplogroups and haplotypes of the Y-chromosome and the mtDNA (Table 3).

Table 3. AMOVA analysis of main Italian regions (Permutations: 20000; P-value<0.0000) for the mtDNA control region data and the Y-chromosome STRs and SNPs.

doi:10.1371/journal.pone.0050794.t003

AMOVA indicated that, among populations, variance was more strongly stratified for the Y-chromosome than for the mtDNA; the difference was much more marked for the analysis based on haplogroups (14.39% vs 1.17%) than for the analysis based on haplotypes (2.34% vs0.79%). Among population variance was very low when analyzing main geographical regions; however, it was the latitude (North vs Center vs South) that appeared to account for higher values of among-population variance rather than longitude (West vs East), with the exception of the Y-chromosome haplogroups (although the values are below 1%); Table 3. Again, the Y-chromosome showed slightly higher values of among-population variance than did the mtDNA. For the Y-chromosome, a significant proportion of the within-population variance moved to among-population within-groups variance, probably due to the fact that all population samples had a very high proportion of singleton Yfiler haplotypes, elevating the maximum values of haplogroup diversity for all of them [33].

Linguistic isolates: Ladin and Grecani Salentini

Two linguistic isolates are represented in the samples analyzed in the present study: the Ladin and the Grecani Salentini.

Other population samples of the Ladin have already been analyzed in the literature [22], [62],[63]. We here sampled 41 new individuals from the locality of Val Badia. As reported in Table 4for the mtDNA, Val Badia Ladins showed relatively high nucleotide diversity patterns compared to other Ladin populations, but intermediate haplotype diversity values. Compared to other Italian populations, diversity in Ladin populations is generally lower (Table 1). For Y-chromosome haplogroups, the differences between Ladin and the rest of Italy were more evident, with the Ladin showing much lower values than average Italians.

Table 4. Mitochondrial DNA molecular diversity values of different Ladin populations.

doi:10.1371/journal.pone.0050794.t004

The differences between Ladin and other populations were more evident when examining haplogroup frequency patterns (Figure 4). The frequency of haplogroup H (58%) was above the frequency of H in North Italy (55%), and was extremely high (58%) compared to the average for Italy (38%) (Pearson's Chi-square test, P-value = 0.0005). While haplogroup U was found to have approximately the same frequency as other Italian populations, haplogroup T was 5% compared to 12% in Italy generally (7% in the North). Other differences were apparent, but sample sizes were relatively low to yield significant statistical differences.

Figure 4. Haplogroup frequencies of Ladins, Grecani Salentini and Lucera compared to the rest of the Italian populations analyzed in the present study.

doi:10.1371/journal.pone.0050794.g004

Differences are more important when examining Y-chromosome haplogroup frequencies. R1b3 reached 52% in Ladin populations but only 31% in the general population, and also in the North (Pearson's Chi-square test, P-value = 0.0087); Figure 4. More remarkable are the differences when considering the remaining R1b lineages, that is, R1b(xR1b3), which account for 15% of the lineages in Ladins, but only for 1% in the general population (Pearson's Chi-square test, P-value = 0.0001). Other haplogroups showed substantial haplogroup differences (e.g. J2) but the sample size was again too small.

Due to the availability of data for mtDNA in several Ladin communities, we were able to carry out an AMOVA analysis in order to investigate the level of population stratification in these communities. The data indicated that among-population variance is 1.09%, a value that is therefore higher than the average for the Italian Peninsula (0.79%; Table 4).

Some interesting features were also found for Ladin populations when examined at the haplotype level. For instance, the HVS-I profile G16129A C16192T A16270G T16304C was found in four Ladins from Val Badía; this profile belongs to haplogroup U5b3f [20]. In a large in-house database of worldwide profiles (>130,000 HVS-I segments), this sequence was only found sporadically in other Italian regions and in Spain (Catalonia, Galicia, and Ibiza in the Balearic Islands). U5b3f is a minor clade of U5b3, the only haplogroup reported to date that has been found to represent the glacial refuge zone in Northern Italy and a source population for human re-colonization of the continent at the beginning of the Holocene. The study of Pala et al. [20] indicates that this lineage mainly expanded along the Mediterranean coast towards the Iberian Peninsula; one sub-clade also reached Sardinia 7000–9000 years ago. The branch observed in the Ladins is younger and could also have participated in the Mediterranean spread of U5b3f towards Iberia, given its presence in modern-day Spain. The data suggest that the U5b3f members observed in the Ladins probably predate the Ladin ethnogenesis and, given that this population has somehow become isolated from other neighboring populations, could reach a substantial frequency in some other Ladin communities, as is the case for the Val Badia. Another example is the U3 profile A16233G C16256T T16311C A16343G, which was only found in five Ladins from Alto Adige (Val Badia and Val Gardena), while T16352C C16354T was found in six individuals from Val Badia in South Tyrol.

Diversity values in the Grecani Salentini samples were similar to those observed in other Italian regions. Moreover, they also show haplogroup frequency patters in the Y-chromosome and the mtDNA that matches well with other Italian samples. The haplogroups are typically European (Figure 4); given the southern location of the Grecani Salentini in the Italian Peninsula, it is noticeable that there is no evidence of North African lineages. Note however, that at higher level of phylogenetic resolution, there are signals on the Y-chromosome of North African enrichment in South Italy [31].

The North African historical legacy in South Italy

We sampled 60 individuals from Lucera. This population sample showed diversity values that fell within the average of a typical Italian population, regarding the mtDNA (Table 1) and the Y-chromosome (Table 2). Additionally, at the level of haplogroup frequencies, Lucera matched well with other Italian populations (Figure 4).

There are two mtDNA haplogroups, namely U6 and M1 that can be considered to be of North African origin and could therefore be used to signal the documented historical input of this African region into Lucera. In our full set of samples, we observed five U6 haplotypes belonging to sub-haplogroups U6a, U6a2, and U6a4. Only one of these haplotypes was observed in Lucera. However, the other three U6 haplotypes were observed in the vicinity of the population of South Apulia, and another at the tip of the Peninsula (Calabria). Regarding M1 haplotypes, we observed only two carriers in our samples sharing the same HVS-I haplotype; both were found in Trapani (West Sicily).

Therefore, while South Italy shows evidence of having female introgression from North Africa, this African influence seems not to be particularly centered in the Lucera. In the Y-chromosome, we did not observe any signal of North African introgression; at least, no more than for other regions of Italy (perhaps with the exception of Sicily [31]). This again contrasts with the results of previous studies based on the Y-chromosome (but at higher or different level of phylogenetic resolution involving the genotyping of African minor sub-lineages) where signals of North African influence were observed at this latitude of the Peninsula [31].

Discussion

A meta-analysis of Y-chromosome and mtDNA sequence data was undertaken in order to investigate patterns of genetic variation throughout Italy. Molecular indices indicated that most of the Italian samples show diversity values that are comparable to other European populations. However, some differences were shown to exist, especially in isolated Ladin populations. Regional differences were much more evident when examining haplogroup frequencies in both uniparental markers. The differences were again more remarkable for the two linguistic isolates, the Ladins and Grecani Salentini. AMOVA also indicated the existence of significant population stratification along the length of the country, which appeared more remarkable for the Y-chromosome and for haplogroups than for haplotypes. These figures have however to be considered with caution given the different mutability of the markers being analyzed [64]; see also a discussion in [65].

Over the last few years, the interest in genetically isolated populations has increased, especially in biomedical studies, where there exists a growing interest in revealing genetic variants associated to disease. Genetic isolates generally originate as a result of group “foundation” by a small number of individuals presenting initially low variability. We have here analyzed a new sample of the Ladins, a well-known linguistic and genetic isolate from the Italian Alps. Some investigations were focused on the Ladin Romance speaking populations, distributed between Trentino, the Veneto regions and South Tyrol area [22], [62], [63], [66]. As also observed in the present study, Ladin communities show marked genetic differentiation with neighboring (non-Ladin) populations. Differences were also observed between the different Ladin groups; for instance, AMOVA analysis also indicated that the different Ladin communities show a level of population stratification that is higher than the average in the rest of Italy. These results are also consistent with the recent study by Coia et al. [67], derived from micro-geographical analysis of nine sample populations from Trentino (Eastern Italian Alps). Genetic differences between Ladin samples are most likely to be due to the limited historical gene flow existing between these communities [22]. In this regard, it is also noticeable that, while the South Tyrol populations show clear signatures of isolation, the Veneto groups presented a high degree of genetic variability [68].

The Grecani Salentini also showed signatures of genetic isolation when compared to other Italian populations, but the differences are not as marked as observed for the Ladins. The differences with respect to neighboring Italian populations were not evident when observing individual haplotypes (as occurs with the Ladins), but were clearer when considering haplogroup frequencies (Figure 4). Larger sample sizes are needed in order to gather more signatures about the demographic past of this population. Thus, the Ladins show a more distinctive pattern than the Grecani Salentini, which is to be expected given that not only is the Ladin population a linguistic isolate, but also that these communities are confined to isolated geographical areas of the Alps.

Apart from the regional and local genetic differences observed in Italy, it is also worth examining global genetic patterns along the length of continental Italy.

Geographical clines of Y-chromosome haplogroups in Europe have been previously reported in the literature [13]; these patterns have found support in archaeological and linguistic evidence. In the Italian peninsula, the Y-chromosome variation also shows a clinal pattern along the North–South axis; the Mesolithic haplogroup R1*(xR1a1) shows higher frequency in the North while the Neolithic haplogroup J2-M172 is superposed to this Mesolithic strata with frequency patterns running in the opposite direction [14], [69]. The results of the present study agreed with these earlier findings. Thus, for instance, R1b3 reached 31% in the North, 16% in the Center, and 14% in the South. Frequency of Y-chromosome haplogroup J2 was found to be 9% in the North, 37% in the Center, and 22% in the South (average in Italy: 14.5%). Haplogroup J2 is widely believed to be associated with the spread of agriculture from Mesopotamia. The main spread of J2 into the Mediterranean area is thought to have coincided with the expansion of agricultural populations during the Neolithic period. As reported by Di Giacomo et al. [12], haplogroup J “…constitutes not only the signature of a single wave-of-advance from the Levant but, to a greater extent, also of the expansion of the Greek world, with an accompanying novel quota of genetic variation produced during its demographic growth…”; also that “…in the central and west Mediterranean, the entry of J chromosomes may have occurred mainly by sea, i.e., in the south–east of both Spain and Italy…”. J2-M12 is almost totally represented by its sublineage J2-M102, which shows frequency peaks in both the southern Balkans and north-central Italy (14%; [13]). J2-M67 is most frequent in the Caucasus, and J2-M92 indicates affinity between Anatolia and southern Italy (21.6%; [13]). For the J1-M170 clade, the peaks of J1-M267 are in the Levant and in northern Africa, and it is closely associated to the diffusion of the Arab people, dropping abruptly outside of this area (including Anatolia and the Iberian peninsula), even if it shows an appreciable percentage in Sicily [70]. In a recent study, Pala et al. [71] confirmed that mtDNA haplogroups J and T and their major sub-clades (J1 and J2, T1 and T2) most likely arose in the Near East at the time of the first settlement by modern humans and the LGM. These haplogroups started to spread from the Near East into Europe immediately after the peak of the last glaciation, about 19 kya ago, with a major expansions in Europe in the Late Glacial period, about 16–12 kya ago, thus indicating that many of the Neolithic expansions from southern Europe into Central Europe and the Mediterranean might have been indigenous dispersal of these lineages.

Latitudinal clinal frequency patterns are also observed for the mtDNA haplogroups mirroring those of the Y-chromosome. As reported by Richards et al. [38], haplogroups H, K, T*, T2, W, and X are the major contributors to the Late Upper Paleolithic, and the central-Mediterranean region has the greatest Middle Upper Paleolithic component outside the Caucasus. In agreement with the Y-chromosome, we observed that all these Paleolithic haplogroups together add to approximately 70.3% in the North, 60.8% in the Center, and 54% in the South of Italy. The opposite pattern was observed for the main mtDNA Neolithic component, represented by haplogroups J and T1, which accounted for 5.8% in the North, 10.3% in the Center, and 14.1% in the South (Italian average: 10.5%).

As early as 1934, [72], Vere Gordon Childe suggested that the indigenous communities of hunters and gatherers of the Mesolithic European cultures were replaced by communities of farmers migrating to the North from the Middle East, a process that lasted for several generations. The first stream of emigration followed the route along the continental Balkan Peninsula and the Danube, while another, slightly later, emigration spread along the coasts of the Mediterranean Sea from East to West. The latter path would fit well with the distribution of other Neolithic cultural features, such as the so-called Cardium Pottery (or Cardial Ware) [73], the ceramic decorative style that better defines the Neolithic culture. This culture entered from Greece towards the South-Center of Italy through the Adriatic Sea, carried by the same farmers that introduced, for instance, Y-chromosome haplogroup J2 at about the same frequency in Central and South Italy, but with lower introgression into the North; from here followed further Mediterranean expansions towards Iberia.

The sub-clade E3b1 (probably originating in eastern Africa) has a wide distribution in sub-Saharan Africa, Middle East and Europe. This haplogroup reaches a frequency of 8% in the North and Center and slightly higher in the South of Italy, 11% (Figure 1). It has also been argued that the European distribution of E3b1 is compatible with the Neolithic demic diffusion of agriculture [15]; thus, two sub-clades, E3b1a- M78 and E3b1c-M123 present a higher occurrence in Anatolia, the Balkans and the Italian peninsula. Another sub-clade, E3b1b-M81 is associated with the Berber populations and is commonly found in regions that have had historical gene flow with Northern Africa, such as the Iberian peninsula [74], [75]–[76]–[78], including the Canary Islands [75], and Sicily [70], [79]; the absence of microsatellite variation suggests a very recent arrival from North Africa [80]. If we assume that all E3b1 represents the only Y-chromosome continental African contribution to Italy and L and U6 lineages the continental African mtDNA component, the African component in Italy is higher for the Y-chromosome (8–11%) than for mtDNA (1–2%). The origin of sub-Saharan African mtDNAs in Europe (including Italian samples) has been recently investigated by Cerezo et al. [81]; the results indicate that a significant proportion of these lineages could have arrived in Italy more than 10,000 years ago; therefore, their presence in Europe does not necessarily date to the time of the Roman Empire, the Atlantic slave trade or to modern migration.

In addition, the Northern African influence in the Italian Peninsula is evidenced by the presence of Northern African Y chromosome haplogroups (E1-M78) in three geographically close samples across the southern Apennine mountains: East Campania, Northwest Apulia and Lucera [31]. The Lucera sample analyzed in the present study did not however show a higher impact from North Africa than for other areas from southern Italy [31].

Finally, in agreement with uniparental markers, analysis of AIMs as carried out in the present study indicated that Italy shows a very minor sub-Saharan African component that is, however, slightly higher than non-Mediterranean Europe. This agrees with the recent findings of Cerezo et al. [82] based on the analysis of entire mtDNA genomes pointing to the arrival in ancient and historical times of sub-Saharan African people to the Mediterranean Europe, followed by admixture.

The present study represents the largest meta-analysis carried out to date for the Italian peninsula. We observed that the Y-chromosome and the mtDNA retain the imprint of the major ancestral events occurring in Italy; however, the Y-chromosome shows more marker regional differences than does the mtDNA. It is difficult to infer what proportion of these differences can be attributed not only exclusively to gender demographic differences, but also to the fact that both markers were analyzed to different levels of molecular resolution. Italy shows clines of variation attributable to the demographic movements of the first Paleolithic settlements, posteriorly modeled by the Mesolithic and, to a lesser extent, Neolithic farmers. Regional differences arose with time, which are more notable in linguistic isolates, such as the Ladin populations, and to a minor extent, the Grecani Salentini. Lot of effort has been dedicated during the last two decades to the study of Italian populations. Further studies are needed in order to dig into some of the many demographic movements occurring in the Italian peninsula along history. Entire genome sequencing of particular lineages (in the line of e.g. [20]) and nuclear DNA genomic studies are needed in order to explore hypothesis beyond what has been done to date in Italy.

Table S1.

mtSNPs and primers used to characterize J/T and U and some of their sub-clades.

doi:10.1371/journal.pone.0050794.s001

(XLS)

Table S2.

References to the population samples used in the present study for population comparison analysis.

doi:10.1371/journal.pone.0050794.s002

(XLS)

Table S3.

Mitochondrial DNA control region haplotypes obtained from the samples analyzed in the present study.

doi:10.1371/journal.pone.0050794.s003

(XLS)

Table S4.

Y-SNP and Y-STR profiles of the Italian samples analyzed in the present study. Note that the Y-STR data has already been reported in Brisighelli et al. [65].

doi:10.1371/journal.pone.0050794.s004

(XLS)

Acknowledgments

We would like to thank two anonymous reviewers for their very useful comments on the present study.

Author Contributions

Conceived and designed the experiments: FB CC AS. Performed the experiments: FB VAI MF ABV. Analyzed the data: FB AS. Contributed reagents/materials/analysis tools: AC VLP AS. Wrote the paper: FB AS. Critically revised the paper and made suggestions on a first draft: CC. Approved the final version of the manuscript: FB VAI MF ABV AC VLP AS.

References

1.Cunliffe B (2001) The Oxford Illustrated History of Prehistoric Europe: Oxford University Press.
2.Guidi A, Piperno M (2005) Italia preistorica. Roma: Laterza.
3.Abulafia D (2001) The Great Sea: A human history of the Mediterranean Oxford University Press.
4.Buti GG (1974) Preistoria e storia delle regioni d'Italia: Sansoni Università.
5.Devoto G (1977) Gli antichi italici: Firenze, Vallecchi.
6.Pallottino M (1981) Genti e culture dell'Italia preromana. Jouvence 136. Find this article online
7.Stenico M, Nigro L, Barbujani G (1998) Mitochondrial lineages in Ladin-speaking communities of the eastern Alps. Proc R Soc Lond B 265: 555–561. doi:10.1098/rspb.1998.0330. Find this article online
8.Achilli A, Olivieri A, Pala M, Metspalu E, Fornarino S, et al. (2007) Mitochondrial DNA variation of modern Tuscans supports the near eastern origin of Etruscans. Am J Hum Genet 80: 759–768. doi: 10.1086/512822. Find this article online
9.Brisighelli F, Capelli C, Álvarez-Iglesias V, Onofri V, Paoli G, et al. (2009) The Etruscan timeline: A recent Anatolian connection. Eur J Hum Genet 17: 693–696. doi:10.1038/ejhg.2008.224. Find this article online
10.Francalacci P, Bertranpetit J, Calafell F, Underhill PA (1996) Sequence diversity of the control region of mitochondrial DNA in Tuscany and its implications for the peopling of Europe. Am J Phys Anthropol 100: 443–460. doi: 10.1002/(SICI)1096-8644(199608)100:4<443::AID-AJPA1>3.0.CO;2-S. Find this article online
11.Onofri V, Alessandrini F, Turchi C, Fraternale B, Buscemi L, et al. (2007) Y-chromosome genetic structure in sub-Apennine populations of Central Italy by SNP and STR analysis. Int J Legal Med 121: 234–237. doi: 10.1007/s00414-007-0153-y. Find this article online
12.Di Giacomo F, Luca F, Anagnou N, Ciavarella G, Corbo RM, et al. (2003) Clinal patterns of human Y chromosomal diversity in continental Italy and Greece are dominated by drift and founder effects. Mol Phylogenet Evol 28: 387–395. doi:10.1016/S1055-7903(03)00016-2. Find this article online
13.Semino O, Passarino G, Oefner PJ, Lin AA, Arbuzova S, et al. (2000) The genetic legacy of Paleolithic Homo sapiens sapiens in extant Europeans: A Y chromosome perspective. Science 290: 1155–1159. doi: 10.1126/science.290.5494.1155. Find this article online
14.Capelli C, Brisighelli F, Scarnicci F, Arredi B, Caglia A, et al. (2007) Y chromosome genetic variation in the Italian peninsula is clinal and supports an admixture model for the Mesolithic-Neolithic encounter. Mol Phylogenet Evol 44: 228–239. doi:10.1016/j.ympev.2006.11.030. Find this article online
15.Semino O, Magri C, Benuzzi G, Lin AA, Al-Zahery N, et al. (2004) Origin, diffusion, and differentiation of Y-chromosome haplogroups E and J: Inferences on the neolithization of Europe and later migratory events in the Mediterranean area. Am J Hum Genet 74: 1023–1034. doi: 10.1086/386295. Find this article online
16.Trombetta B, Cruciani F, Sellitto D, Scozzari R (2011) A new topology of the human Y chromosome haplogroup E1b1 (E-P2) revealed through the use of newly characterized binary polymorphisms. PLoS ONE 6: e16073. doi: 10.1371/journal.pone.0016073. Find this article online
17.Francalacci P, Sanna D (2008) History and geography of human Y-chromosome in Europe: A SNP perspective. J Anthropol Sci 86: 59–89. Find this article online
18.Di Gaetano C, Cerutti N, Crobu F, Robino C, Inturri S, et al. (2009) Differential Greek and northern African migrations to Sicily are supported by genetic evidence from the Y chromosome. Eur J Hum Genet 17: 91–99. doi: 10.1038/ejhg.2008.120. Find this article online
19.Brigaglia M (1989) Storia della Sardegna. Edizioni Della Torre Find this article online
20.Pala M, Achilli A, Olivieri A, Kashani BH, Perego UA, et al. (2009) Mitochondrial haplogroup U5b3: A distant echo of the epipaleolithic in Italy and the legacy of the early Sardinians. Am J Hum Genet 84: 814–821. doi: 10.1016/j.ajhg.2009.05.004. Find this article online
21.Montanini L, Regna-Gladin C, Eoli M, Albarosa R, Carrara F, et al. (2005) Instability of mitochondrial DNA and MRI and clinical correlations in malignant gliomas. J Neurooncol 74: 87–89. doi: 10.1007/s11060-004-4036-5. Find this article online
22.Thomas MG, Barnes I, Weale ME, Jones AL, Forster P, et al. (2008) New genetic evidence supports isolation and drift in the Ladin communities of the South Tyrolean Alps but not an ancient origin in the Middle East. Eur J Hum Genet 16: 124–134. doi:10.1038/sj.ejhg.5201906. Find this article online
23.Achilli A, Rengo C, Magri C, Battaglia V, Olivieri A, et al. (2004) The molecular dissection of mtDNA haplogroup H confirms that the Franco-Cantabrian glacial refuge was a major source for the European gene pool. Am J Hum Genet 75: 910–918. doi:10.1086/425590. Find this article online
24.Torroni A, Bandelt H-J, Macaulay V, Richards M, Cruciani F, et al. (2001) A signal, from human mtDNA, of postglacial recolonization in Europe. Am J Hum Genet 69: 844–852. doi: 10.1086/323485. Find this article online
25.Álvarez-Iglesias V, Mosquera-Miguel A, Cerezo M, Quintáns B, Zarrabeitia MT, et al. (2009) New population and phylogenetic features of the internal variation within mitochondrial DNA macro-haplogroup R0. PLoS One 4: e5112. doi:10.1371/journal.pone.0005112. Find this article online
26.Gómez-Carballa A, Olivieri A, Behar DM, Achilli A, Torroni A, et al. (2012) Genetic continuity in the Franco-Cantabrian region: New clues from autochthonous mitogenomes. PLoS ONE 7: e32851. doi: 10.1371/journal.pone.0032851. Find this article online
27.De Concini W (2003) Gli altri d'Italia: minoranze linguistiche allo specchio Pergine Valsugana (TN).
28.Castagnetti A (2004) Storia del Trentino. (L'età Medievale). 3 Vol, Bologna, Il Mulino, 2000–2005.
29.De Concini W (1997) Gli altri delle Alpi. Minoranze linguistiche dell'arco alpino italiano. Trento, Grafiche Artigianelli.
30.Carducci L (1993) Storia del Salento. La terra de'Otranto dale origini ai primi del cinquecento. Galatina: Congedo.
31.Capelli C, Onofri V, Brisighelli F, Boschi I, Scarnicci F, et al. (2009) Moors and Saracens in Europe: Estimating the medieval North African male legacy in southern Europe. Eur J Hum Genet 17: 848–852. doi: 10.1038/ejhg.2008.258. Find this article online
32.Norman D (1975) The Arabs and Medieval Europe. London, UK Longmann Group Limited.
33.Brisighelli F, Blanco-Verea A, Boschi I, Garagnani P, Pascali VL, et al. (2011) Global patterns of Y-STR variation in Italy. Forensic Sci Int Genet in press; 10.1016/j.fsigen.2012.03.003. Find this article online
34.Miller SA, Dykes DD, Polesky HF (1988) A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res 16: 1215. doi:10.1093/nar/16.3.1215. Find this article online
35.Álvarez-Iglesias V, Jaime JC, Carracedo Á, Salas A (2007) Coding region mitochondrial DNA SNPs: targeting East Asian and Native American haplogroups. Forensic Sci Int Genet 1: 44–55. doi: 10.1016/j.fsigen.2006.09.001. Find this article online
36.Anderson S, Bankier AT, Barrell BG, de Bruijn MHL, Coulson AR, et al. (1981) Sequence and organization of the human mitochondrial genome. Nature 290: 457–465. doi: 10.1038/290457a0. Find this article online
37.Quintáns B, Álvarez-Iglesias V, Salas A, Phillips C, Lareu MV, et al. (2004) Typing of mitochondrial DNA coding region SNPs of forensic and anthropological interest using SNaPshot minisequencing. Forensic Sci Int 140: 251–257. doi:10.1016/j.forsciint.2003.12.005. Find this article online
38.Richards M, Macaulay V, Hickey E, Vega E, Sykes B, et al. (2000) Tracing European founder lineages in the Near Eastern mtDNA pool. Am J Hum Genet 67: 1251–1276. doi: 10.1086/321197. Find this article online
39.Brión M, Sobrino B, Blanco-Verea A, Lareu MV, Carracedo Á (2005) Hierarchical analysis of 30 Y-chromosome SNPs in European populations. Int J Legal Med 119: 10–15. doi: 10.1007/s00414-004-0439-2. Find this article online
40.YCC (2002) A nomenclature system for the tree of human Y-chromosomal binary haplogroups. Genome Res 12: 339–348. doi: 10.1101/gr.217602. Find this article online
41.Sánchez JJ, Phillips C, Børsting C, Balogh K, Bogus M, et al. (2006) A multiplex assay with 52 single nucleotide polymorphisms for human identification. Electrophoresis 27: 13–24. doi: 10.1002/elps.200500671. Find this article online
42.Amigo J, Salas A, Phillips C (2011) ENGINES: exploring single nucleotide variation in entire human genomes. BMC Bioinformatics 12: 105. doi: 10.1186/1471-2105-12-105.Find this article online
43.Amigo J, Salas A, Phillips C, Carracedo Á (2008) SPSmart: adapting population based SNP genotype databases for fast and comprehensive web access. BMC Bioinformatics 9: 428. doi: 10.1186/1471-2105-9-428. Find this article online
44.Nei N (1987) Molecular evolutionary genetics: New York: Columbia University Press.
45.Tajima F (1983) Evolutionary relationship of DNA sequences in finite populations. Genetics 105: 437–460. Find this article online
46.Tajima F (1993) Unbiased estimation of evolutionary distance between nucleotide sequences. Mol Biol Evol 10: 677–688. Find this article online
47.Rozas J, Sanchez-DelBarrio JC, Messeguer X, Rozas R (2003) DnaSP, DNA polymorphism analyses by the coalescent and other methods. Bioinformatics 19: 2496–2497. doi: 10.1093/bioinformatics/btg359. Find this article online
48.Excoffier L, Lischer HEL (2010) Arlequin suite ver 3.5: A new series of programs to perform population genetics analyses under Linux and Windows. Mol Ecol Res 10: 564–567. doi: 10.1111/j.1755-0998.2010.02847.x. Find this article online
49.Loogväli E-L, Roostalu U, Malyarchuk BA, Derenko MV, Kivisild T, et al. (2004) Disuniting uniformity: A pied cladistic canvas of mtDNA haplogroup H in Eurasia. Mol Biol Evol 21: 2012–2021. doi: 10.1093/molbev/msh209. Find this article online
50.Macaulay V, Richards M, Hickey E, Vega E, Cruciani F, et al. (1999) The emerging tree of West Eurasian mtDNAs: a synthesis of control-region sequences and RFLPs. Am J Hum Genet 64: 232–249. doi: 10.1086/302204. Find this article online
51.van Oven M, Kayser M (2009) Updated comprehensive phylogenetic tree of global human mitochondrial DNA variation. Hum Mutat 30: E386–394. doi:10.1002/humu.20921. Find this article online
52.Salas A, Yao Y-G, Macaulay V, Vega A, Carracedo A, et al. (2005) A critical reassessment of the role of mitochondria in tumorigenesis. PLoS Med 2: e296. doi:10.1371/journal.pmed.0020296. Find this article online
53.Salas A, Prieto L, Montesino M, Albarrán C, Arroyo E, et al. (2005) Mitochondrial DNA error prophylaxis: Assessing the causes of errors in the GEP'02-03 proficiency testing trial. Forensic Sci Int 148: 191–198. doi: 10.1016/j.forsciint.2004.06.008. Find this article online
54.Salas A, Carracedo Á, Macaulay V, Richards M, Bandelt H-J (2005) A practical guide to mitochondrial DNA error prevention in clinical, forensic, and population genetics. Biochem Biophys Res Commun 335: 891–899. doi: 10.1016/j.bbrc.2005.07.161. Find this article online
55.Salas A, Bandelt H-J, Macaulay V, Richards MB (2007) Phylogeographic investigations: The role of trees in forensic genetics. Forensic Sci Int 168: 1–13. doi:10.1016/j.forsciint.2006.05.037. Find this article online
56.Yao Y-G, Salas A, Logan I, Bandelt H-J (2009) mtDNA data mining in GenBank needs surveying. Am J Hum Genet 85: 929–933; author reply 933. doi:10.1016/j.ajhg.2009.10.023. Find this article online
57.Bandelt H-J, Salas A, Lutz-Bonengel S (2004) Artificial recombination in forensic mtDNA population databases. Int J Legal Med 118: 267–273. doi: 10.1007/s00414-004-0455-2. Find this article online
58.Bandelt H-J, Salas A, Bravi CM (2004) Problems in FBI mtDNA database. Science 305: 1402–1404. doi: 10.1126/science.305.5689.1402b. Find this article online
59.Bandelt H-J, Quintana-Murci L, Salas A, Macaulay V (2002) The fingerprint of phantom mutations in mitochondrial DNA data. Am J Hum Genet 71: 1150–1160. doi:10.1086/344397. Find this article online
60.Olivieri A, Achilli A, Pala M, Battaglia V, Fornarino S, et al. (2006) The mtDNA legacy of the Levantine early Upper Palaeolithic in Africa. Science 314: 1767–1770. doi:10.1126/science.1135566. Find this article online
61.Salas A, Richards M, De la Fé T, Lareu MV, Sobrino B, et al. (2002) The making of the African mtDNA landscape. Am J Hum Genet 71: 1082–1111. doi: 10.1086/344348. Find this article online
62.Vernesi C, Fuselli S, Castri L, Bertorelle G, Barbujani G (2002) Mitochondrial diversity in linguistic isolates of the Alps: A reappraisal. Hum Biol 74: 725–730. doi:10.1353/hub.2002.0060. Find this article online
63.Pichler I, Mueller JC, Stefanov SA, De Grandi A, Beu Volpato C, et al. (2006) Genetic structure in contemporary South Tyrolean isolated populations revealed by analysis of Y-Chromosome, mtDNA, and Alu polymorphisms. Hum Biol 78: 441–464. doi:10.1353/hub.2006.0057. Find this article online
64.Meirmans PG, Hedrick PW (2011) Assessing population structure: F(ST) and related measures. Mol Ecol Resour 11: 5–18. doi: 10.1111/j.1755-0998.2010.02927.x. Find this article online
65.Brisighelli F, Blanco-Verea A, Boschi I, Garagnani P, Pascali VL, et al. (2012) Patterns of Y-STR variation in Italy. Forensic Sci Int Genet in press. doi:10.1016/j.fsigen.2012.03.003. Find this article online
66.Stenico M, Nigro L, Bertorelle G, Calafell F, Capitanio M, et al. (1996) High Mitochondrial Sequence Diversity in Linguistic Isolates of the Alps. Am J Hum Genet 59: 1363–1375. Find this article online
67.Coia V, Boschi I, Trombetta F, Cavulli F, Montinaro F, et al. (2012) Evidence of high genetic variation among linguistically diverse populations on a micro-geographic scale: a case study of the Italian Alps. J Hum Genet 57: 254–260. doi: 10.1038/jhg.2012.14.Find this article online
68.Destro Bisol G, Anagnostou P, Batini C, Battaggia C, Bertoncini S, et al. (2008) Italian isolates today: geographic and linguistic factors shaping human biodiversity. J Anthropol Sci 86: 179–188. Find this article online
69.Busby GB, Brisighelli F, Sánchez-Diz P, Ramos-Luis E, Martinez-Cadenas C, et al. (2012) The peopling of Europe and the cautionary tale of Y chromosome lineage R-M269. Proc Biol Sci 279: 884–892. doi: 10.1098/rspb.2011.1044. Find this article online
70.Semino O, Magri C, Benuzzi G, Lin AA, Al-Zahery N, et al. (2004) Origin, diffusion, and differentiation of Y-chromosome haplogroups E and J: Inferences on the neolithization of Europe and later migratory events in the Mediterranean area. Am J Hum Genet 74: 1023–1034. doi: 10.1086/386295. Find this article online
71.Pala M, Olivieri A, Achilli A, Accetturo M, Metspalu E, et al. (2012) Mitochondrial DNA signals of late glacial recolonization of Europe from near eastern refugia. Am J Hum Genet 90: 915–924. doi: 10.1016/j.ajhg.2012.04.003. Find this article online
72.Childe VG (1934) New light on the most ancient East: The oriental Prelude to European prehistory: London: K Paul, Trench, Trubner & Co.
73.King R, Underhill P (2002) Congruent distribu- tion of Neolithic painted pottery and ceramic figurines with Y-chromosome lineages. Antiquity 76: 707–714. Find this article online
74.Maca-Meyer N, Sanchez-Velasco P, Flores C, Larruga JM, Gonzalez AM, et al. (2003) Y chromosome and mitochondrial DNA characterization of Pasiegos, a human isolate from Cantabria (Spain). Ann Hum Genet 67: 329–339. doi: 10.1046/j.1469-1809.2003.00045.x. Find this article online
75.Flores C, Maca-Meyer N, Perez JA, Gonzalez AM, Larruga JM, et al. (2003) A predominant European ancestry of paternal lineages from Canary Islanders. Ann Hum Genet 67: 138–152. doi: 10.1046/j.1469-1809.2003.00015.x. Find this article online
76.Goncalves R, Freitas A, Branco M, Rosa A, Fernandes AT, et al. (2005) Y-chromosome lineages from Portugal, Madeira and Acores record elements of Sephardim and Berber ancestry. Ann Hum Genet 69: 443–454. doi: 10.1111/j.1529-8817.2005.00161.x. Find this article online
77.Alonso S, Flores C, Cabrera V, Alonso A, Martin P, et al. (2005) The place of the Basques in the European Y-chromosome diversity landscape. Eur J Hum Genet 13: 1293–1302. doi: 10.1038/sj.ejhg.5201482. Find this article online
78.Beleza S, Gusmão L, Lopes A, Alves C, Gomes I, et al. (2006) Micro-phylogeographic and demographic history of Portuguese male lineages. Ann Hum Genet 70: 181–194. doi: 10.1111/j.1529-8817.2005.00221.x. Find this article online
79.Cruciani F, La Fratta R, Santolamazza P, Sellitto D, Pascone R, et al. (2004) Phylogeographic analysis of haplogroup E3b (E-M215) y chromosomes reveals multiple migratory events within and out of Africa. Am J Hum Genet 74: 1014–1022. doi:10.1086/386294. Find this article online
80.Bosch E, Calafell F, Comas D, Oefner PJ, Underhill PA, et al. (2001) High-resolution analysis of human Y-chromosome variation shows a sharp discontinuity and limited gene flow between northwestern Africa and the Iberian Peninsula. Am J Hum Genet 68: 1019–1029. doi: 10.1086/319521. Find this article online
81.Cerezo M, Achilli A, Olivieri A, Perego UA, Gómez-Carballa A, et al. (2012) Reconstructing ancient mitochondrial DNA links between Africa and Europe. Genome Res in press. doi: 10.1101/gr.134452.111. Find this article online
82.Cerezo M, Achilli A, Olivieri A, Perego UA, Gómez-Carballa A, et al. (2012) Reconstructing ancient mitochondrial DNA links between Africa and Europe. Genome Res 22: 821–826. doi: 10.1101/gr.134452.111. Find this article online
83.Amigo J, Phillips C, Salas A, Carracedo A (2009) Viability of in-house datamarting approaches for population genetics analysis of SNP genotypes. BMC Bioinformatics 10: S5. doi: 10.1186/1471-2105-10-S3-S5. Find this article online
84.Turchi C, Buscemi L, Giacchino E, Onofri V, Fendt L, et al. (2009) Polymorphisms of mtDNA control region in Tunisian and Moroccan populations: An enrichment of forensic mtDNA databases with Northern Africa data. Forensic Sci Int Genet 3: 166–172. doi:10.1016/j.fsigen.2009.01.014. Find this article online
85.Messina F, Scorrano G, Labarga CM, Rolfo MF, Rickards O Mitochondrial DNA variation in an isolated area of Central Italy. Ann Hum Biol 37: 385–402. doi:10.3109/03014461003720304. Find this article online
86.Babalini C, Martínez-Labarga C, Tolk HV, Kivisild T, Giampaolo R, et al. (2005) The population history of the Croatian linguistic minority of Molise (southern Italy): A maternal view. Eur J Hum Genet 13: 902–912. doi: 10.1038/sj.ejhg.5201439. Find this article online
87.Falchi A, Giovannoni L, Calo CM, Piras IS, Moral P, et al. (2006) Genetic history of some western Mediterranean human isolates through mtDNA HVR1 polymorphisms. J Hum Genet 51: 9–14. doi: 10.1007/s10038-005-0324-y. Find this article online
88.Verginelli F, Donati F, Coia V, Boschi I, Palmirotta R, et al. (2003) Variation of the hypervariable region-1 of mitochondrial DNA in central-eastern Italy. J Forensic Sci 48: 443–444. Find this article online
89.Bini C, Ceccardi S, Luiselli D, Ferri G, Pelotti S, et al. (2003) Different informativeness of the three hypervariable mitochondrial DNA regions in the population of Bologna (Italy). Forensic Sci Int 135: 48–52. doi: 10.1016/S0379-0738(03)00167-1. Find this article online
90.Tagliabracci C, Turchi C, Buscemi L, Sassaroli C (2001) Polymorphism of the mitochondrial DNA control region in Italians. Int J Legal Med 114: 224–228. doi:10.1007/s004140000168. Find this article online
91.Ottoni C, Martinez-Labarga C, Vitelli L, Scano G, Fabrini E, et al. (2009) Human mitochondrial DNA variation in Southern Italy. Ann Hum Biol 36: 785–811. doi:10.3109/03014460903198509. Find this article online
92.Rose G, Longo T, Maletta R, Passarino G, Bruni AC, et al. (2008) No evidence of association between frontotemporal dementia and major European mtDNA haplogroups. Eur J Neurol 15: 1006–1008. doi: 10.1111/j.1468-1331.2008.02222.x. Find this article online
93.Ottoni C, Martinez-Labarga C, Loogvali EL, Pennarun E, Achilli A, et al. (2009) First genetic insight into Libyan Tuaregs: a maternal perspective. Ann Hum Genet 73: 438–448. doi: 10.1111/j.1469-1809.2009.00526.x. Find this article online
94.Cali F, Le Roux MG, D'Anna R, Flugy A, De Leo G, et al. (2001) MtDNA control region and RFLP data for Sicily and France. Int J Legal Med 114: 229–231. doi:10.1007/s004140000169. Find this article online
95.Forster P, Cali F, Rohl A, Metspalu E, D'Anna R, et al. (2002) Continental and subcontinental distributions of mtDNA control region types. Int J Legal Med 116: 99–108. doi: 10.1007/s00414-001-0261-z. Find this article online
96.Vona G, Ghiani ME, Calo CM, Vacca L, Memmi M, et al. (2001) Mitochondrial DNA sequence analysis in Sicily. Am J Hum Biol 13: 576–589. doi: 10.1002/ajhb.1096. Find this article online
97.Di Rienzo A, Wilson AC (1991) Branching pattern in the evolutionary tree for human mitochondrial DNA. Proc Natl Acad Sci U S A 88: 1597–1601. doi:10.1073/pnas.88.5.1597. Find this article online
98.Ferri G, Ceccardi S, Lugaresi F, Bini C, Ingravallo F, et al. (2008) Male haplotypes and haplogroups differences between urban (Rimini) and rural area (Valmarecchia) in Romagna region (North Italy). Forensic Sci Int 175: 250–255. doi:10.1016/j.forsciint.2007.06.007. Find this article online
99.Ferri G, Alu M, Corradini B, Radheshi E, Beduschi G (2009) Slow and fast evolving markers typing in Modena males (North Italy). Forensic Sci Int Genet 3: e31–33. doi:10.1016/j.fsigen.2008.05.004. Find this article online
100.Contu D, Morelli L, Santoni F, Foster JW, Francalacci P, et al. (2008) Y-chromosome based evidence for pre-neolithic origin of the genetically homogeneous but diverse Sardinian population: Inference for association scans. PLoS One 3: e1430. doi:10.1371/journal.pone.0001430. Find this article online

Source: