Produção Nacional
Revisado por pares
The Peopling of the Americas: A Second Major Migration?
2002; Elsevier BV; Volume: 70; Issue: 5 Linguagem: Inglês
10.1086/340388
ISSN1537-6605
AutoresEduardo Tarazona‐Santos, Fabrício R. Santos,
Tópico(s)Race, Genetics, and Society
ResumoTo the Editor: Recently, Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) analyzed the distribution of Y-chromosome haplogroups in a set of Siberian and Native American individuals. They inferred that there is evidence of two major migrations that originated from Siberia and peopled the Western Hemisphere. The first one coincides with our previous finding (Santos et al. Santos et al., 1999Santos FR Pandya A Tyler-Smith C Pena SD Schanfield M Leonard WR Osipova L Crawford MH Mitchell RJ The central Siberian origin for Native American Y chromosomes.Am J Hum Genet. 1999; 64: 619-628Abstract Full Text Full Text PDF PubMed Scopus (169) Google Scholar) and that of Karafet et al. (Karafet et al., 1999Karafet TM Zegura SL Posukh O Osipova L Bergen A Long J Goldman D Klitz W Harihara S de Knijff P Wiebe V Griffiths RC Templeton AR Hammer MF Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.Am J Hum Genet. 1999; 64: 817-831Abstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar). In addition, Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) suggest that a later major migration, which likely originated in eastern Siberia, would have carried the haplogroups S4Y (as previously suggested by Karafet at al. [Karafet et al., 1999Karafet TM Zegura SL Posukh O Osipova L Bergen A Long J Goldman D Klitz W Harihara S de Knijff P Wiebe V Griffiths RC Templeton AR Hammer MF Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.Am J Hum Genet. 1999; 64: 817-831Abstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar]) and M45b. We argue that the claim of a second major migration is not well grounded and is altogether not necessary to explain the distribution of the haplogroups S4Y and M45b in Native American populations. On the basis of detailed molecular information associated with the most common Native American M3 haplogroup and its immediately ancestral M45a haplogroup, Santos et al. (Santos et al., 1999Santos FR Pandya A Tyler-Smith C Pena SD Schanfield M Leonard WR Osipova L Crawford MH Mitchell RJ The central Siberian origin for Native American Y chromosomes.Am J Hum Genet. 1999; 64: 619-628Abstract Full Text Full Text PDF PubMed Scopus (169) Google Scholar), Karafet et al. (Karafet et al., 1999Karafet TM Zegura SL Posukh O Osipova L Bergen A Long J Goldman D Klitz W Harihara S de Knijff P Wiebe V Griffiths RC Templeton AR Hammer MF Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.Am J Hum Genet. 1999; 64: 817-831Abstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar), and Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) have consistently identified central Siberia as the most likely region of origin of the present-day Native American Y chromosomes. We suppose that, when this “first” major migration occurred, the central Siberian population was polymorphic, like most if not all human populations. Natural populations usually contain few common alleles and several rare ones, but only a subset of the total rare alleles will be represented in a sample of, for example, 10–50 individuals (Ewens Ewens, 1972Ewens WJ The sampling theory of selectively neutral alleles.Theor Popul Biol. 1972; 3: 87-112Crossref PubMed Scopus (1349) Google Scholar; Helgason et al. Helgason et al., 2000Helgason A Sigurðardóttir S Gulcher JR Ward R Stefansson K mtDNA and the origin of the Icelanders: deciphering signals of recent population history.Am J Hum Genet. 2000; 66: 999-1016Abstract Full Text Full Text PDF PubMed Scopus (164) Google Scholar). When a population movement occurs, migrants reflect (more or less) the distribution of the source population. Therefore, we expect that most migrants carry common alleles but also that some of them carry rare ones. The first settlement of the Americas has been associated with a probable bottleneck event (Wallace et al. Wallace et al., 1985Wallace DC Garrison K Knowler WC Dramatic founder effects in Amerindian mitochondrial DNAs.Am J Phys Anthropol. 1985; 68: 149-155Crossref PubMed Scopus (119) Google Scholar; Pena et al. Pena et al., 1995Pena SDJ Santos FR Bianchi NO Bravi CM Carnese FR Rothhammer F Gerelsaikhan T Munkhtuja B Oyunsuren T A major founder Y-chromosome haplotype in Amerindians.Nat Genet. 1995; 11: 15-16Crossref PubMed Scopus (81) Google Scholar; Bonatto and Salzano Bonatto and Salzano, 1997bBonatto SL Salzano FM A single and early migration for the peopling of the Americas supported by mitochondrial DNA sequence data.Proc Natl Acad Sci USA. 1997b; 94: 1866-1871Crossref PubMed Scopus (200) Google Scholar Santos et al. Santos et al., 1999Santos FR Pandya A Tyler-Smith C Pena SD Schanfield M Leonard WR Osipova L Crawford MH Mitchell RJ The central Siberian origin for Native American Y chromosomes.Am J Hum Genet. 1999; 64: 619-628Abstract Full Text Full Text PDF PubMed Scopus (169) Google Scholar). It could have produced drastic changes in allele frequencies and reduced the number of rare alleles; however, even if this were the case, it does not mean that the genetic variability completely disappeared. The ancient haplogroup S4Y has a wide and heterogeneous distribution in eastern Asia. In central Siberia, the putative region of the “first” migration, its frequencies are 2/12 in Kets, 2/122 in Selkups (Karafet et al. Karafet et al., 1999Karafet TM Zegura SL Posukh O Osipova L Bergen A Long J Goldman D Klitz W Harihara S de Knijff P Wiebe V Griffiths RC Templeton AR Hammer MF Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.Am J Hum Genet. 1999; 64: 817-831Abstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar), 13/40 in Tuvan, 2/19 in Tofalars, and 18/31 in Yenisey Evenks (Lell et al. Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar). Among the 31 Native American populations in which the presence of the haplogroup S4Y has been tested, only four samples exhibit this allele—always at low frequencies (1%, 16%, and 7%)—and only one sample of 12 Tanana individuals from North America presents five S4Y chromosomes (95% CI 12%–62%). Therefore, it is clear that the S4Y haplogroup is a rare allele in Native American populations. Since we have no reason to believe that the individuals carrying the haplogroup S4Y were prohibited from migrating at the time of the first settlement of the continent, we do not think that it is necessary to claim an ex novo major migration to explain the presence of this haplogroup at low frequencies in Native American populations. Instead, the most parsimonious explanation for its presence in the American indigenous population seems to be that it entered as a rare allele during the first settlement of the continent. Indigenous samples from Central and North America have low frequencies of the haplogroups S4Y and M45b. On the other hand, eastern Siberian samples coincidentally show the higher frequencies of the haplogroups S4Y and M45b (even if the latter is altogether a rare allele). Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) present this observation as evidence that a second major migration originated in eastern Siberia. Actually, these populations exhibit frequencies of the S4Y haplogroup that are 40%–100%. Under the two-major-migrations model, the Native American population would be an admixed population with two parental ones: (1) the central Middle Siberian and (2) the Lower Amur/Okhotsk populations. We used the classical Bernstein formula (Cavalli-Sforza and Bodmer Cavalli-Sforza and Bodmer, 1971Cavalli-Sforza LL Bodmer WF The genetics of human populations. W.H. Freeman, San Francisco1971Google Scholar) to calculate the contribution of each putative parental population to the current gene pool of Native American populations. The S4Y haplogroup could be useful for this purpose because it has the highest difference in allele frequencies among the parental population (δ=0.45) and is not affected by recent European or African migration. Using the data presented by Karafet et al. (Karafet et al., 1999Karafet TM Zegura SL Posukh O Osipova L Bergen A Long J Goldman D Klitz W Harihara S de Knijff P Wiebe V Griffiths RC Templeton AR Hammer MF Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.Am J Hum Genet. 1999; 64: 817-831Abstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar) and Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar), we considered as parental populations the central southern Siberia region (Yenisey Evenk, Tuvan, Tofalar, Buryat, Ket, and Selkup samples were clumped) and the Lower Amur/Okhotsk region (Okhotsk, Ulchi, Negidal Upp, Negidal Low, Udigey, Nivkh, Buriat, Siberian Evenk, Even, Manchurian Evenk, Oroquen, and Yakut samples were clumped). The calculated contribution of the Lower Amur/Okhotsk population to the current gene pool of the Native American population would be −26% (a negative value, because the frequency in the Native American population is lower than that in central southern Siberia). Although this is a rough measure of admixture, subject to a high stochastic variance, it illustrates that the proposal of a second major migration, even intuitively, is hardly compatible with current data. The obtained value is clearly more compatible with a null contribution of the Lower Amur/Okhotsk population. Again, we do not need to claim a second major migration to explain the variability of Native American Y chromosomes. When its wide distribution is considered, the haplogroup S4Y seems to be very ancient (Karafet et al. Karafet et al., 1999Karafet TM Zegura SL Posukh O Osipova L Bergen A Long J Goldman D Klitz W Harihara S de Knijff P Wiebe V Griffiths RC Templeton AR Hammer MF Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.Am J Hum Genet. 1999; 64: 817-831Abstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar; Underhill et al. Underhill et al., 2000Underhill PA Shen P Lin AA Jin L Passarino G Yang WH Kauffman E Bonne-Tamir B Bertranpetit J Francalacci P Ibrahim M Jenkins T Kidd JR Mehdi SQ Seielstad MT Wells RS Piazza A Davis RW Feldman MW Cavalli-Sforza LL Oefner PJ Y chromosome sequence variation and the history of human populations.Nat Genet. 2000; 26: 358-361Crossref PubMed Scopus (742) Google Scholar), and its presence in central southern Siberia at the time of first migration to the Americas is also compatible with current data. Furthermore, although Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar, p. 204) state that their data “demonstrate that the Native American RPS4Y-T haplogroup originated in the eastern Siberian populations,” we were not able to find that demonstration in the article. Because the authors do not disclose to the public the complete information about the frequencies and distribution of S4Y-microsatellite haplotypes, we are not able to discuss this point. However, we anticipate that the above pending demonstration must include an adequate assessment of its statistical significance. Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) suggest that the distribution of 22 Y chromosomes belonging to the rare haplogroup M45b also supports the existence of the second major migration from eastern Siberia. According to Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar), the 17 M45b chromosomes observed in the Americas would have an eastern Siberian origin. We have an alternative explanation for the origin of a consistent portion of the 17 M45b chromosomes found in the Americas, which is—we think—simpler and perhaps obvious: Since the M45b haplogroup is largely the most frequent in virtually all western European populations (Semino et al. Semino et al., 2000Semino O Passarino G Oefner PJ Lin AA Arbuzova S Beckman LE De Benedictis G Francalacci P Kouvatsi A Limborska S Marcikiae M Mika A Mika B Primorac D Santachiara-Benerecetti AS Cavalli-Sforza LL Underhill PA The genetic legacy of Paleolithic Homo sapiens sapiens in extant Europeans: a Y chromosome perspective.Science. 2000; 290: 1155-1159Crossref PubMed Scopus (621) Google Scholar), these chromosomes could have been introduced into Native American populations by Europeans during the last five centuries. In fact, evidence of European admixture in Native American populations, especially in North and Central America, is straightforward and comes from population-genetics, demographic, and historical studies (see Crawford [Crawford, 1998Crawford M The origin of Native Americans: evidence from archeological genetics. Cambridge University Press, Cambridge1998Crossref Google Scholar], Salzano and Callegari-Jacques [Salzano and Callegari-Jacques, 1988Salzano F Callegari-Jacques S South America Indians, a case study in evolution. Clarendon Press, Oxford1988Google Scholar], and the second principal component of Amerindian genetic variability shown by Cavalli-Sforza et al. [Cavalli-Sforza et al., 1994Cavalli-Sforza L Menozzi P Piazza A The history and geography of human genes. Princeton University Press, Princeton, NJ1994Google Scholar]). Furthermore, several genetic studies have shown that European admixture in the Americas has been preferentially mediated by males (Merriwether et al. Merriwether et al., 1997Merriwether DA Huston S Iyengar S Hamman R Norris JM Shetterly SM Kamboh MI Ferrell RE Mitochondrial versus nuclear admixture estimates demonstrate a past history of directional mating.Am J Phys Anthropol. 1997; 102: 153-159Crossref PubMed Scopus (38) Google Scholar; Carvajal-Carmona et al. Carvajal-Carmona et al., 2000Carvajal-Carmona LG Soto ID Pineda N Ortiz-Barrientos D Duque C Ospina-Duque J McCarthy M Montoya P Alvarez VM Bedoya G Ruiz-Linares A Strong Amerind/white sex bias and a possible sephardic contribution among the founders of a population in northwest Colombia.Am J Hum Genet. 2000; 67: 1287-1295Abstract Full Text Full Text PDF PubMed Scopus (204) Google Scholar; Carvalho-Silva et al. Carvalho-Silva et al., 2001Carvalho-Silva DR Santos FR Rocha J Pena SD The phylogeography of Brazilian Y-chromosome lineages.Am J Hum Genet. 2001; 68: 281-286Abstract Full Text Full Text PDF PubMed Scopus (264) Google Scholar). Therefore, in populations in which evidence of admixture exists, like the Seminole or the Boruca (14%; Sans Sans, 2000Sans M Admixture studies in Latin America: from the 20th to the 21st century.Hum Biol. 2000; 72: 155-177PubMed Google Scholar), we should expect to find some level of European Y-chromosome contribution, as is clearly evidenced by previous studies (Pena et al. Pena et al., 1995Pena SDJ Santos FR Bianchi NO Bravi CM Carnese FR Rothhammer F Gerelsaikhan T Munkhtuja B Oyunsuren T A major founder Y-chromosome haplotype in Amerindians.Nat Genet. 1995; 11: 15-16Crossref PubMed Scopus (81) Google Scholar; Santos et al. Santos et al., 1995Santos FR Hutz MH Coimbra CEA Santos RV Salzano FM Pena SDJ Further evidence for the existence of major founder Y chromosome haplotype in Amerindians.Braz J Genet. 1995; 18: 669-672Google Scholar, Santos et al., 1996bSantos FR Rodriguez-Delfin L Pena SDJ Moore J Weiss KM North and South Amerindians may have the same major founder Y chromosome haplotype.Am J Hum Genet. 1996b; 58: 1369-1370PubMed Google Scholar Bianchi et al. Bianchi et al., 1997Bianchi NO Bailliet G Bravi CM Carnese RF Rothhammer F Martinez-Marignac VL Pena SD Origin of Amerindian Y-chromosomes as inferred by the analysis of six polymorphic markers.Am J Phys Anthropol. 1997; 102: 79-89Crossref PubMed Scopus (71) Google Scholar; Karafet et al. Karafet et al., 1999Karafet TM Zegura SL Posukh O Osipova L Bergen A Long J Goldman D Klitz W Harihara S de Knijff P Wiebe V Griffiths RC Templeton AR Hammer MF Ancestral Asian source(s) of new world Y-chromosome founder haplotypes.Am J Hum Genet. 1999; 64: 817-831Abstract Full Text Full Text PDF PubMed Scopus (234) Google Scholar; Ruiz-Linares et al. Ruiz-Linares et al., 1999Ruiz-Linares A Ortiz-Barrientos D Figueroa M Mesa N Munera JG Bedoya G Velez ID Garcia LF Perez-Lezaun A Bertranpetit J Feldman MW Goldstein DB Microsatellites provide evidence for Y chromosome diversity among the founders of the New World.Proc Natl Acad Sci USA. 1999; 96: 6312-6317Crossref PubMed Scopus (77) Google Scholar). For instance, our group has previously demonstrated that the most common European Y-chromosome haplotype (defined by the alleles αh-II and DYS19-B), which we refer to as “II-B” (Santos et al. Santos et al., 1996aSantos FR Bianchi NO Pena SDJ Worldwide distribution of human Y-chromosome haplotypes.Genome Res. 1996a; 6: 601-611Crossref PubMed Scopus (53) Google Scholar) and which is equivalent to M45b (data not shown), is present at higher frequencies in Native American populations such as the Muskokes of North America, who have a long documented history of contact and admixture with Europeans (Santos et al. Santos et al., 1996bSantos FR Rodriguez-Delfin L Pena SDJ Moore J Weiss KM North and South Amerindians may have the same major founder Y chromosome haplotype.Am J Hum Genet. 1996b; 58: 1369-1370PubMed Google Scholar). Curiously, even though Wallace’s group has previously reported in the Seminole sample the presence of 11% of Y chromosomes with likely European origin (Huoponen et al. Huoponen et al., 1997Huoponen K Torroni A Wickman PR Sellitto D Gurley DS Scozzari R Wallace DC Mitochondrial DNA and Y chromosome-specific polymorphisms in the Seminole tribe of Florida.Eur J Hum Genet. 1997; 5: 25-34PubMed Google Scholar), in the Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) article they ignore this possibility but consider the eventuality of male African admixture, which is generally less likely than European admixture. Furthermore, in accordance with their probable recent European origin, the microsatellite haplotypes found by Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) in the M45b chromosomes match very well with those present in the phylogenetically equivalent haplogroup 1 chromosomes of Basques, Catalans, Norwegians, French, and Italians (Hurles et al. Hurles et al., 1999Hurles ME Veitia R Arroyo E Armenteros M Bertranpetit J Perez-Lezaun A Bosch E Shlumukova M Cambon-Thomsen A McElreavey K Lopez De Munain A Rohl A Wilson IJ Singh L Pandya A Santos FR Tyler-Smith C Jobling MA Recent male-mediated gene flow over a linguistic barrier in Iberia, suggested by analysis of a Y-chromosomal DNA polymorphism.Am J Hum Genet. 1999; 65: 1437-1448Abstract Full Text Full Text PDF PubMed Scopus (118) Google Scholar; Ruiz-Linares et al. Ruiz-Linares et al., 1999Ruiz-Linares A Ortiz-Barrientos D Figueroa M Mesa N Munera JG Bedoya G Velez ID Garcia LF Perez-Lezaun A Bertranpetit J Feldman MW Goldstein DB Microsatellites provide evidence for Y chromosome diversity among the founders of the New World.Proc Natl Acad Sci USA. 1999; 96: 6312-6317Crossref PubMed Scopus (77) Google Scholar; Carvajal-Carmona et al. Carvajal-Carmona et al., 2000Carvajal-Carmona LG Soto ID Pineda N Ortiz-Barrientos D Duque C Ospina-Duque J McCarthy M Montoya P Alvarez VM Bedoya G Ruiz-Linares A Strong Amerind/white sex bias and a possible sephardic contribution among the founders of a population in northwest Colombia.Am J Hum Genet. 2000; 67: 1287-1295Abstract Full Text Full Text PDF PubMed Scopus (204) Google Scholar; Rosser et al. Rosser et al., 2001Rosser ZH Zerjal T Hurles ME Adojaan M Alavantic D Amorim A Amos W et al.Y-chromosomal diversity in Europe is clinal and influenced primarily by geography, rather than by language.Am J Hum Genet. 2001; 67: 1526-1543Abstract Full Text Full Text PDF Scopus (458) Google Scholar). Therefore, if we consider that a consistent portion of the 16 M45b chromosomes found in North and Central America very likely arrived during the last five centuries and that only 6 M45b chromosomes were found in eastern Siberia, very few chromosomes are left for making any robust inference about the genetic structure of populations or “major migrations.” In any case, in Siberian populations, the association claimed by Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) between central and eastern Siberia and the distribution of M45a and M45b haplogroups is far from reaching any acceptable significance level (Fisher exact test: P=.25), which means that any derived conclusion, such as the eastern Siberian origin of the Native American M45b chromosomes, is at least temerarious. Perhaps the only valid observation we can make is that the M45b haplogroup is a rare one either in native populations of northeastern Asia or in the Americas. We think that Lell et al. (Lell et al., 2002Lell JT Sukernik RI Starikovskaya YB Su B Jin L Schurr TG Underhill PA Wallace DC The dual origin and Siberian affinities of Native American Y chromosomes.Am J Hum Genet. 2002; 70: 192-206Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar) have not provided any solid evidence about the existence of a second “major migration,” and we think that the simplest way to reconcile the currently available molecular genetic data, which are mainly derived from Y chromosomes and mtDNA (Bonatto and Salzano Bonatto and Salzano, 1997aBonatto SL Salzano FM Diversity and age of the four major mtDNA haplogroups, and their implications for the peopling of the New World.Am J Hum Genet. 1997a; 61: 1413-1423Abstract Full Text Full Text PDF PubMed Scopus (120) Google ScholarBonatto and Salzano, 1997bBonatto SL Salzano FM A single and early migration for the peopling of the Americas supported by mitochondrial DNA sequence data.Proc Natl Acad Sci USA. 1997b; 94: 1866-1871Crossref PubMed Scopus (200) Google Scholar), is to assume a single major migration from Siberia contributing to the gene pool of Native American populations. The authors are grateful to Silvia Fuselli, Ripan Mahli, Chris Tyler-Smith, Sarah Tishkoff, Isa Dupanloup, Giorgio Bertorelle, and Juliana Alves-Silva, for discussions.
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