复旦大学：《人类进化 Human Evolution》参考文献_分子人类学_Y-Chromosome Evidence for a Northward Migration of Modern Humans into Eastern Asia during the Last Ice Age

Am.J.Hnm. Genet.65:1718-1724,1999 Y-Chromosome Evidence for a northward migration of Modern Humans into Eastern Asia during the Last Ice Age Bing Su, Junhua Xiao, Peter Underhill, Ranjan Deka, Weiling Zhang Joshua Akey, Wei Huang,, 4 Di Shen, Daru Lu, 2 Jingchun Luo, Jiayou Chu, Jiazhen Tan, 2 Peidong Shen, 5 Ron Davis, ,b Luca Cavalli-Sforza, Ranajit Chakraborty Momiao Xiong, Ruofu Du, Peter Oefner, b Zhu Chen , and Li jin Human Genetics Center, University of Texas-Houston, Houston nter for Life Sciences and Institute of genetics Fudan University, io pie ai Second Medical University, Shangha Department of Genetics, Stanford University, and Stanford DNA Center, Palo Alto;Department of Environmental Health, University of Cincinnati, Cincinnati; Insti cal Biology, The Chinese Academy of Medical Sciences, Kunming, Yunnan, China; and Institute of Genetics, The Chinese Sciences, Beijing Summary arrival there(Brooks and Wood 1990; Li and Etler 1992 Wu and Poirier 1995; Etler 1996; Wolpoff 1996), which The timing and nature of the arrival and the subsequent has been claimed to be a challenge to the well-known expansion of modern humans into eastern Asia remains "out-of-Africa"hypothesis of modern human evolution controversial. Using Y-chromosome biallelic markers, (Cann et al. 1987; Vigilant et al. 1991). However,not we investigated the ancient human-migration patterns in all paleoanthropologists agree that the Asian fossil rec eastern Asia. Our data indicate that southern popula- ord shows a clear continuity from Homo erectus to H tions in eastern Asia are much more polymorphic than sapiens sapiens(Stringer and Andrew 1988; Wilson and northern populations, which have only a subset of the Cann 1992), thereby casting doubt on the in situ Asian- southern haplotypes. This pattern indicates that the first origin hypothesis settlement of modern humans in eastern Asia occurred A recent study of Asian populations, which used mi in mainland Southeast Asia during the last Ice Age, co- crosatellite markers, questioned the validity of the in situ inciding with the absence of human fossils in eastern Asian-origin hypothesis and suggested that modern hu Asia, 50,000-100,000 years ago. After the initial peo- mans in eastern Asia originated from Africa( Chu et al. pling, a great northward migration extended into north- 1998). It also confirmed the previous observation of the ern China and Siberia substantial genetic and morphological differences be- tween northern and southern Mongoloids(Zhao et al 1986; Weng et al. 1989)and suggested that such dif- ferences could be attributed to a northward migration n eastern Asia(Chu et al. 1998). However, the stud Introduction fell short of providing unequivocal evidence in support of this hypothesis, because of the high mutation rates Although the expansions of modern humans into Eu- associated with the microsatellite markers used(Chu et rope, the Americas, and Oceania are now relatively well al. 1998). Therefore, a systematic study based on stable characterized, little is known of the earliest migratory and informative biallelic markers would shed more light routes by which modern humans spread from western on the prehistoric migrations in eastern Asia to eastern Asia( Cavalli-Sforza et al. 1994). Eastern Asia Recently, researchers have recognized the power of Y- is one of the few regions with relatively abundant hom- chromosome markers in resolving the migratory patterns inid fossils that span the last several hundreds of of modern humans Jobling and Tyler-Smith 1995).The thousands of years. Such evidence suggests the possi- introduction of denaturing high-performance liquid bility of continuous in situ evolution of Homo since its chromatography, a powerful mutation-detection tech nique, has made it possible to efficiently identify biallelic Received August 6, 1999, accepted for publication September 8, markers on Y chromosomes(Oefner and Underhill 1999; electronically published November 2, 1999 1995, 1998; Underhill et al. 1996, 1997b). The biallelic Address for correspondence and reprints: Dr. Li Jin, Human Genet Center, University of Texas-Houston, 6901 Bertmer, Hous ston, Tx markers are single-base changes or small indels that usu- 7030. E-mail: Ijin @utsph. sph uth. tmc.edu ally have occurred only once during the evolution of e 1999 by The American Society of Human Genetics. All rights reserve human y chromosomes and that are therefore m 00029297/9996506-002802.00 ble than microsatellite loci. The markers on the nonre

Am. J. Hum. Genet. 65:1718–1724, 1999 1718 Y-Chromosome Evidence for a Northward Migration of Modern Humans into Eastern Asia during the Last Ice Age Bing Su,1 Junhua Xiao,2 Peter Underhill,5 Ranjan Deka,7 Weiling Zhang,2 Joshua Akey,1 Wei Huang,3,4 Di Shen,1 Daru Lu,2 Jingchun Luo,2 Jiayou Chu,8 Jiazhen Tan,2 Peidong Shen,5 Ron Davis,5,6 Luca Cavalli-Sforza,5 Ranajit Chakraborty,1 Momiao Xiong,1 Ruofu Du,9 Peter Oefner,5,6 Zhu Chen,3,4 and Li Jin1,2,3 1 Human Genetics Center, University of Texas-Houston, Houston; 2 Morgan-Tan International Center for Life Sciences and Institute of Genetics, Fudan University, 3 National Human Genome Center at Shanghai, and 4 Rui-Jin Hospital, Shanghai Second Medical University, Shanghai; 5 Department of Genetics, Stanford University, and 6 Stanford DNA Sequencing and Technology Center, Palo Alto; 7 Department of Environmental Health, University of Cincinnati, Cincinnati; 8 Institute of Medical Biology, The Chinese Academy of Medical Sciences, Kunming, Yunnan, China; and 9 Institute of Genetics, The Chinese Academy of Sciences, Beijing Summary The timing and nature of the arrival and the subsequent expansion of modern humans into eastern Asia remains controversial. Using Y-chromosome biallelic markers, we investigated the ancient human-migration patterns in eastern Asia. Our data indicate that southern popula￾tions in eastern Asia are much more polymorphic than northern populations, which have only a subset of the southern haplotypes. This pattern indicates that the first settlement of modern humans in eastern Asia occurred in mainland Southeast Asia during the last Ice Age, co￾inciding with the absence of human fossils in eastern Asia, 50,000–100,000 years ago. After the initial peo￾pling, a great northward migration extended into north￾ern China and Siberia. Introduction Although the expansions of modern humans into Eu￾rope, the Americas, and Oceania are now relatively well characterized, little is known of the earliest migratory routes by which modern humans spread from western to eastern Asia (Cavalli-Sforza et al. 1994). Eastern Asia is one of the few regions with relatively abundant hom￾inid fossils that span the last several hundreds of thousands of years. Such evidence suggests the possi￾bility of continuous in situ evolution of Homo since its Received August 6, 1999; accepted for publication September 8, 1999; electronically published November 2, 1999. Address for correspondence and reprints: Dr. Li Jin, Human Genet￾ics Center, University of Texas-Houston, 6901 Bertner, Houston, TX 77030. E-mail: ljin@utsph.sph.uth.tmc.edu q 1999 by The American Society of Human Genetics. All rights reserved. 0002-9297/1999/6506-0028$02.00 arrival there (Brooks and Wood 1990; Li and Etler 1992; Wu and Poirier 1995; Etler 1996; Wolpoff 1996), which has been claimed to be a challenge to the well-known “out-of-Africa” hypothesis of modern human evolution (Cann et al. 1987; Vigilant et al. 1991). However, not all paleoanthropologists agree that the Asian fossil rec￾ord shows a clear continuity from Homo erectus to H. sapiens sapiens (Stringer and Andrew 1988; Wilson and Cann 1992), thereby casting doubt on the in situ Asian￾origin hypothesis. A recent study of Asian populations, which used mi￾crosatellite markers, questioned the validity of the in situ Asian-origin hypothesis and suggested that modern hu￾mans in eastern Asia originated from Africa (Chu et al. 1998). It also confirmed the previous observation of the substantial genetic and morphological differences be￾tween northern and southern Mongoloids (Zhao et al. 1986; Weng et al. 1989) and suggested that such dif￾ferences could be attributed to a northward migration in eastern Asia (Chu et al. 1998). However, the study fell short of providing unequivocal evidence in support of this hypothesis, because of the high mutation rates associated with the microsatellite markers used (Chu et al. 1998). Therefore, a systematic study based on stable and informative biallelic markers would shed more light on the prehistoric migrations in eastern Asia. Recently, researchers have recognized the power of Y￾chromosome markers in resolving the migratory patterns of modern humans (Jobling and Tyler-Smith 1995). The introduction of denaturing high-performance liquid chromatography, a powerful mutation-detection tech￾nique, has made it possible to efficiently identify biallelic markers on Y chromosomes (Oefner and Underhill 1995, 1998; Underhill et al. 1996, 1997b). The biallelic markers are single-base changes or small indels that usu￾ally have occurred only once during the evolution of human Y chromosomes and that are therefore more sta￾ble than microsatellite loci. The markers on the nonre-

Su et al. Modern Human Migration in Eastern Asia 1719 combinant part of the y chromosome allow the recon- derhill, P Shen, A. A Lin, L. Jin, G. Passarino, W.H. struction of intact haplotypes, which are not likely to Yang, E. Kauffman, E.S. Dietrich, J. Kidd, S.Q. Mehdi be eroded by recombination and recurrent mutation and T. Jenkins, R S. Wells, M. T Seielstad, M. Ibrahim, P. which are, therefore, highly informative for tracing an- Francalacci, J. Bertranpetit, R. W. Davis, L. L. Cavalli cient human migrations. Given the fact that Y chro- Sforza, and P. J. Oefner, unpublished data), since they mosomes have a smaller effective population size are polymorphic in the individuals of eastern-Asian or- than do autosomes, Y-chromosome-specific polymor- igin, in the screening set used. For genotyping, an allelic- phic markers are probably the best genetic tool to study specific PCR assay was used for Y-chromosome biallelic early human migrations as bottleneck events that are markers. For each Y locus, two allele-specific primers often associated with such migrations become more pro- were designed to recognize two different alleles at this nouns locus(the primer sequences are available on request) In this study, a set of Y-chromosome biallelic and mi- After PCR, the products were visualized through agarose crosatellite markers were used to examine the genetic gel electrophoresis. In addition, three Y-chromosome mi structure of eastern-Asian populations. The Y-chromo- crosatellite loci-DYS389, DYS390, and DYS391 some haplotype distribution in extant eastern-Asian were also typed as described by Kayser et al. ( 1997) populations was used to reconstruct ancient migration The phylogenetic tree for the Y-chromosome haplotypes patterns within this region was constructed on the basis of the parsimony rule, and multifurcation was introduced to accommodate equally Material and Methods DNA Sample Statistica/ Method From worldwide populations, we collected 925 male To estimate the age of M122C haplotypes in the Han DNA samples, of which 739 were from eastern-Asian Chinese, we used the equation t=-N In(1-V/N m) populations. The collection of DNA samples from mem- We derived this equation from the single- step mutation bers of 21 Chinese ethnic-minority populations was model for a haploid population, assuming that popu- done with the coordination of the Chinese Human Ge- lation size (where N is the effective population size whe ected toa y Project. The Chinese Han samples were stayed constant, that V is the variance of repeat numbers n persons living in 22 provincial areas in the population, and that m is the mutation rate. If ose geographic origins were assigned according to the the population undergoes a strong bottleneck event fol birthplaces of their four grandparents. In addition, sam- lowed by a rapid population expansion, it can be shown ples obtained in previous projects were analyzed, in- that this formula is still approximately valid. A widely cluding those from 3 northeast-Asian(Buryat, Korean, accepted estimation of the effective population size of and Japanese)and 5 southeast-Asian( Cambodian, Thai, modern humans is 5,000-10,000, suggested by Taka Malaysian, Batak, and Javanese) populations and from hata(1993). Given a relatively smaller genetic diversity an additional 12 non-Asian populations (3 from Africa, in Asia compared with that seen in Africa, a value of 3 from America, 2 from Europe, and 4 from Oceania) 2,000 is a drastic overestimation of the effective popu (fig. 1 and table 1) lation size for males in eastern Asia. For the level of variance observed in 160 individuals in this study, 750 Genotyping and Phylogenetic-Tree Construction is the minimum integer allowed for the effective popu a total of 19 Y-chromosome biallelic loci were lation size, for the variance observed careened. Seven of them were from previous reports (Vollrath et al. 1992; Underhill et al. 1996, 1997a; Kay. Results ser et al. 1997), including M3(C-T mutation), M (A-G mutation), M7(CG mutation), M9(CG mu- In all the individuals studied for the 19 Y-chromosome tation), M15 (9-bp insertion), M17(1-bp deletion), and biallelic markers, 17 Y haplotypes were obtained. The DYS287(YAP). The other 12 single-nucleotide poly- frequency distribution of Y haplotypes in all the pop morphisms are being first reported here, including M4.5 ulations is listed in table 1. Under the parsimony as (G-A mutation), M50(TC mutation), M88(AG sumption, no recurrent mutations were observed, and a mutation), M89(CT mutation), M95(CT mutation), phylogenetic tree was constructed for the 17 Y haplo M103(C-T mutation), M110(T-+C mutation), Mlll types, in which H1 was considered as the ancestor hap- (4-bp deletion), M119(AC mutation), M120(T-C lotype because of its appearance in chimpanzee(fig. 2) mutation), M122(T-C mutation), and M134 (1-bp de- The H1 and H2 haplotypes are relatively ancient, ap letion). The 19 markers used in this study were selected pearing in both African and non-African populations, from 166 biallelic Y-chromosome markers(P. A. Un- implying that the occurrence of the mutation defining

Su et al.: Modern Human Migration in Eastern Asia 1719 combinant part of the Y chromosome allow the recon￾struction of intact haplotypes, which are not likely to be eroded by recombination and recurrent mutation and which are, therefore, highly informative for tracing an￾cient human migrations. Given the fact that Y chro￾mosomes have a smaller effective population size than do autosomes, Y-chromosome–specific polymor￾phic markers are probably the best genetic tool to study early human migrations as bottleneck events that are often associated with such migrations become more pro￾nounced. In this study, a set of Y-chromosome biallelic and mi￾crosatellite markers were used to examine the genetic structure of eastern-Asian populations. The Y-chromo￾some haplotype distribution in extant eastern-Asian populations was used to reconstruct ancient migration patterns within this region. Material and Methods DNA Samples From worldwide populations, we collected 925 male DNA samples, of which 739 were from eastern-Asian populations. The collection of DNA samples from mem￾bers of 21 Chinese ethnic-minority populations was done with the coordination of the Chinese Human Ge￾nome Diversity Project. The Chinese Han samples were collected from persons living in 22 provincial areas whose geographic origins were assigned according to the birthplaces of their four grandparents. In addition, sam￾ples obtained in previous projects were analyzed, in￾cluding those from 3 northeast-Asian (Buryat, Korean, and Japanese) and 5 southeast-Asian (Cambodian, Thai, Malaysian, Batak, and Javanese) populations and from an additional 12 non-Asian populations (3 from Africa, 3 from America, 2 from Europe, and 4 from Oceania) (fig. 1 and table 1). Genotyping and Phylogenetic-Tree Construction A total of 19 Y-chromosome biallelic loci were screened. Seven of them were from previous reports (Vollrath et al. 1992; Underhill et al. 1996, 1997a; Kay￾ser et al. 1997), including M3 (CrT mutation), M5 (ArG mutation), M7 (CrG mutation), M9 (CrG mu￾tation), M15 (9-bp insertion), M17 (1-bp deletion), and DYS287 (YAP). The other 12 single-nucleotide poly￾morphisms are being first reported here, including M45 (GrA mutation), M50 (TrC mutation), M88 (ArG mutation), M89 (CrT mutation), M95 (CrT mutation), M103 (CrT mutation), M110 (TrC mutation), M111 (4-bp deletion), M119 (ArC mutation), M120 (TrC mutation), M122 (TrC mutation), and M134 (1-bp de￾letion). The 19 markers used in this study were selected from 166 biallelic Y-chromosome markers (P. A. Un￾derhill, P. Shen, A. A. Lin, L. Jin, G. Passarino, W. H. Yang, E. Kauffman, F. S. Dietrich, J. Kidd, S. Q. Mehdi, T. Jenkins, R. S. Wells, M. T. Seielstad, M. Ibrahim, P. Francalacci, J. Bertranpetit, R. W. Davis, L. L. Cavalli￾Sforza, and P. J. Oefner, unpublished data), since they are polymorphic in the individuals of eastern-Asian or￾igin, in the screening set used. For genotyping, an allelic￾specific PCR assay was used for Y-chromosome biallelic markers. For each Y locus, two allele-specific primers were designed to recognize two different alleles at this locus (the primer sequences are available on request). After PCR, the products were visualized through agarose gel electrophoresis. In addition, three Y-chromosome mi￾crosatellite loci—DYS389, DYS390, and DYS391— were also typed as described by Kayser et al. (1997). The phylogenetic tree for the Y-chromosome haplotypes was constructed on the basis of the parsimony rule, and multifurcation was introduced to accommodate equally parsimonious topologies. Statistical Method To estimate the age of M122C haplotypes in the Han Chinese, we used the equation t = 2N ln(1 2 V/N m). e e We derived this equation from the single-step mutation model for a haploid population, assuming that popu￾lation size (where Ne is the effective population size) stayed constant, that V is the variance of repeat numbers in the population, and that m is the mutation rate. If the population undergoes a strong bottleneck event fol￾lowed by a rapid population expansion, it can be shown that this formula is still approximately valid. A widely accepted estimation of the effective population size of modern humans is 5,000–10,000, suggested by Taka￾hata (1993). Given a relatively smaller genetic diversity in Asia compared with that seen in Africa, a value of 2,000 is a drastic overestimation of the effective popu￾lation size for males in eastern Asia. For the level of variance observed in 160 individuals in this study, 750 is the minimum integer allowed for the effective popu￾lation size, for the variance observed. Results In all the individuals studied for the 19 Y-chromosome biallelic markers, 17 Y haplotypes were obtained. The frequency distribution of Y haplotypes in all the pop￾ulations is listed in table 1. Under the parsimony as￾sumption, no recurrent mutations were observed, and a phylogenetic tree was constructed for the 17 Y haplo￾types, in which H1 was considered as the ancestor hap￾lotype because of its appearance in chimpanzee (fig. 2). The H1 and H2 haplotypes are relatively ancient, ap￾pearing in both African and non-African populations, implying that the occurrence of the mutation defining

1720 m.J.Hm. Genet.65:1718-1724,1999 CHINA 19 Man CerN AUSTRALIA gure 1 Geographic map of the 30 eastern-Asian populations. The numbers 1-30 are those used in table 1. The Han Chinese populatic were grouped into northern (population 9)and southern (population 10) populations. The grouping was done by taking the Changjiang River (the eastern part of which is known as the Yangtze River) as the watershed. those haplotypes preceded the initial modern human mi- studied, particularly in the Han Chinese (54.1%on ay gration out of Africa erage), and they are absent in non-Asian populations Interestingly, H5 appears to be the common ancestor (see table 1), indicating that the eastern-Asian popula of all other haplotypes that are regionally distributed, tions in this study were derived from the same ancient and it probably arose after the out-of-Africa migration. population. Moreover, when we compared the frequency In support of this interpretation, H5 and all its deriva- distributions of Y haplotypes of the southern and north tives are distinguished by a CG mutation at locus M9, ern non-Han Asian populations, the haplotypes found whereas all African haplotypes have the C at this locus in the northern populations consisted of only a subset (Underhill et al. 1997a). H15 and H17 are American of those found in the southern populations. For example, Indian- and Oceanian-specific haplotypes, respectively, H7 and H10-H12 were found only in the southern non as previously reported (Underhill et al. 1996, 19976). Han populations and were absent in the non-Han north H14 is present at a high frequency in European popu- ern populations. The probability of not observing the lations but also appears in Oceanians, Asians, and Am- southern-specific haplotypes H7 and H10-H12 in non erindians. Notably, eight haplotypes(H6-H13)are es- Han northern populations is 3. 998 x 10, if we as- sentially Asian specific sume that they occur at the same frequency in both pop- ulations. The difference between the northern ar Discussio ern Han populations remains, although it is less ervasive than that between non-Han populations, since eight aforementioned Asian-specific the recent recorded migrations between southern and types, H6, H7, and H8 share a T-C mutation at northern China have been substantial M122 (see fig. 2). Collectively they are the predominal The difference between southern and northern pop- haplotypes in most of the eastern-Asian populations ulations is further reflected by the results of principal

1720 Am. J. Hum. Genet. 65:1718–1724, 1999 Figure 1 Geographic map of the 30 eastern-Asian populations. The numbers 1–30 are those used in table 1. The Han Chinese populations were grouped into northern (population 9) and southern (population 10) populations. The grouping was done by taking the Changjiang River (the eastern part of which is known as the Yangtze River) as the watershed. those haplotypes preceded the initial modern human mi￾gration out of Africa. Interestingly, H5 appears to be the common ancestor of all other haplotypes that are regionally distributed, and it probably arose after the out-of-Africa migration. In support of this interpretation, H5 and all its deriva￾tives are distinguished by a CrG mutation at locus M9, whereas all African haplotypes have the C at this locus (Underhill et al. 1997a). H15 and H17 are American Indian– and Oceanian-specific haplotypes, respectively, as previously reported (Underhill et al. 1996, 1997b). H14 is present at a high frequency in European popu￾lations but also appears in Oceanians, Asians, and Am￾erindians. Notably, eight haplotypes (H6–H13) are es￾sentially Asian specific. Discussion Of the eight aforementioned Asian-specific haplo￾types, H6, H7, and H8 share a TrC mutation at locus M122 (see fig. 2). Collectively they are the predominant haplotypes in most of the eastern-Asian populations studied, particularly in the Han Chinese (54.1% on av￾erage), and they are absent in non-Asian populations (see table 1), indicating that the eastern-Asian popula￾tions in this study were derived from the same ancient population. Moreover, when we compared the frequency distributions of Y haplotypes of the southern and north￾ern non-Han Asian populations, the haplotypes found in the northern populations consisted of only a subset of those found in the southern populations. For example, H7 and H10–H12 were found only in the southern non￾Han populations and were absent in the non-Han north￾ern populations. The probability of not observing the southern-specific haplotypes H7 and H10–H12 in non￾Han northern populations is 3.998 # 10210, if we as￾sume that they occur at the same frequency in both pop￾ulations. The difference between the northern and south￾ern Han populations remains, although it is less pervasive than that between non-Han populations, since the recent recorded migrations between southern and northern China have been substantial. The difference between southern and northern pop￾ulations is further reflected by the results of principal-

Su et al. Modern Human Migration in Eastern Asia 1721 Table 1 Y-Chromosome Haplotype Frequency Distribution in Eastern-Asian and World Populations CONTINENT AND POPULATION FREQUENCY OF H1 H2 H3 H4 H5 H6 H7 H8 H9 H10 H11 H12 H13 H14 H15 H16 H1 2. Ewenki (8) 12.512.5 16.7 11.122227.8 4. Mongolian(24) 58.34.2 8.312.54.2 6. Japanese (29) 20.727.6 20.7172 10.3 7.Hu(20) 8. Tibetan (8) 12.525125 9. Northern Han(8 2.422.029.3 23.298 Southern 10. Southern Han (280) 1412.92541.827916.8 3.60. 11. Jingpo (5) 13. Yao Nandan(10) 14. Yao Jinxiu(10) 40 3.6 3.6713.63 .7 16.Dong(10) 0201020 17. Bulang (5) 18.Lahu(5) 19.Y1(14) 42.921 7.1 She(11) 18.2 9118227318.2 21. Atayal (24) 29.24.24.254.28 75 23. Paiwan(11) 18.254.627.3 24.Ami(6) 100 1273 26. Cambodian(26) 3.811.511.53.8 1543.83.823.111.5 5 55 28. Malaysian(13) 7.77730.8 1547.723.17 29. Batak(18) 5.611.111.116.7 9127.39.1 18.29118.2 Africa African(24) 0.8792 America: Oceania: 16 The numbers 1-30 preceding the eastern-Asian populations are those used to designate these populations component analysis(fig 3). This analysis showed that bodians and Thais, are the most polymorphic, because all northern populations cluster together at the upper- they exhibit almost all of the Asian-specific haplotypes right corner and are well separated from the southern (see table 1), it is reasonable to conclude that the north eastern-Asian populations, which are far more diversi- ern populations derived from the southern populations fied than the northern populations. Given the obser- and that the first settlement of the ancient African im- vation that Southeast Asian populations, including Cam- migrants was in mainland Southeast Asia, from which

Su et al.: Modern Human Migration in Eastern Asia 1721 Table 1 Y-Chromosome Haplotype Frequency Distribution in Eastern-Asian and World Populations CONTINENT AND POPULATION (NO. OF SUBJECTS) FREQUENCY OF H1 H2 H3 H4 H5 H6 H7 H8 H9 H10 H11 H12 H13 H14 H15 H16 H17 East Asia: a Northern: 1. Buryat (4) 75 25 2. Ewenki (8) 50 12.5 12.5 25 3. Manchurian (18) 16.7 11.1 22.2 27.8 16.7 5.6 4. Mongolian (24) 58.3 4.2 8.3 12.5 4.2 4.2 4.2 4.2 5. Korean (7) 57.1 42.9 6. Japanese (29) 20.7 27.6 20.7 17.2 10.3 3.4 7. Hui (20) 10 5 20 30 20 10 5 8. Tibetan (8) 12.5 25 12.5 50 9. Northern Han (82) 8.5 2.4 22.0 29.3 23.2 9.8 4.9 Southern: 10. Southern Han (280) 7.9 0.4 1.4 12.9 25.4 1.8 27.9 16.8 3.6 0.7 1.4 11. Jingpo (5) 100 12. Tujia (10) 10 20 30 10 20 10 13. Yao Nandan (10) 50 20 30 14. Yao Jinxiu (10) 20 30 10 40 15. Zhuang (28) 3.6 3.6 7.1 3.6 3.6 25 17.9 25 10.7 16. Dong (10) 20 10 20 20 10 20 17. Bulang (5) 20 20 60 18. Lahu (5) 20 60 20 19. Yi (14) 14.3 42.9 21.4 7.1 14.3 20. She (11) 18.2 9.1 18.2 27.3 18.2 9.1 21. Atayal (24) 29.2 4.2 4.2 54.2 8.3 22. Yami (8) 25 75 23. Paiwan (11) 18.2 54.6 27.3 24. Ami (6) 100 25. Li (11) 9.1 27.3 54.6 9.1 26. Cambodian (26) 3.8 3.8 11.5 11.5 3.8 15.4 3.8 3.8 23.1 11.5 3.8 3.8 27. Northeastern Thai (20) 5 5 5 5 5 5 45 20 5 28. Malaysian (13) 7.7 7.7 30.8 15.4 7.7 23.1 7.7 29. Batak (18) 5.6 5.6 11.1 11.1 16.7 22.2 27.8 30. Javanese (11) 9.1 9.1 27.3 9.1 18.2 9.1 18.2 Africa: African (24) 20.8 79.2 America: American Indian (26) 3.8 96.2 Europe: European (39) 10.3 12.8 25.6 51.3 Oceania: Oceanian (100) 16 2 40 4 38 a The numbers 1–30 preceding the eastern-Asian populations are those used to designate these populations in figure 1. component analysis (fig. 3). This analysis showed that all northern populations cluster together at the upper￾right corner and are well separated from the southern eastern-Asian populations, which are far more diversi- fied than the northern populations. Given the obser￾vation that Southeast Asian populations, including Cam￾bodians and Thais, are the most polymorphic, because they exhibit almost all of the Asian-specific haplotypes (see table 1), it is reasonable to conclude that the north￾ern populations derived from the southern populations and that the first settlement of the ancient African im￾migrants was in mainland Southeast Asia, from which

1722 Am.J.Hnm. Genet..65:1718-1724,1999 urred -18,000-25, 000 years ago. A similar dentition LALCACTTCTACGCCTWGG H3 ASCAGTITCACGCGTWGO w pattern predominates among all the Southeast Asian iCACTTTCACGCGTWGG ME populations and was thought to be ancestral to the Sino- L-sASCACTTICACGCGTWDG He dont pattern. Consequently, this sequence of dental ACGCETWGG H5 SASCCCTTTTACGCGTWGG h9 evolution tends to rule out an 18,000-year coloniza tion dating-the lower boundary of our age estima ASCACTITTACGTGTWGG tion- which was based on an overestimated effective 如 SASCACTTTTGCGTGTDGG H1 population size. In addition, archaeological evidence from the Altai Mountain and Lake Baikal regions of SASIACTTTAGACGTWGG MiS southeastern Siberia are beginning to show the presence SASCACTTTTACACGTWGD H of modern human lithic cultures of 25,000-45, 000 years SGSCACTTTTACGCGTWGG H1 ago(Vasil'ev 1993). Therefore, the first entry of eastern sian populations should predate the emergence of the hap. lithic culture in northern Asia. Recent evidence from lotypes in eastern-Asian and world populations. The letters"A, ""T, archaeological studies indicates that Papua New Guinea loci.The was settled -35,000-50,000 years ago by modern hu- letters"S"and "L"refer to small and large alleles, respectively. The mans, aboriginal Australia perhaps even earlier than that letters "W"and "D" refer to wild-type and deletion alleles, respec- (Brown et al. 1992: Swisher et al. 1996).Hence, if we each locus shown above the branches(for detailed descriptions of accept that mainland Southeast Asia is the homeland for mutations, see the Material and Methods section). all eastern-Asian populations, including Siberian and Oceanian, the upper boundary of the M122-lineage time depth-that is, 60,000 years agoseems to be a likely they expanded northward to other parts of eastern Asia. estimation of the initial colonization of eastern Asia by A study by Ballinger et al. (1992)also suggested a south- modern human populations from Africa ern Mongoloid origin of eastern Asians The last Ice Age occurred 75, 000-15,000 years ago To estimate the time of the entry of modern humans although its distribution and the exact date of its pres- nto eastern Asia, we typed three Y-chromosome micro- ence in eastern Asia are not clear(Dawson 1992). In- satellite loci for individuals carrying the C allele at locus M122-that is, the allele state shared by Asian-specific aplotypes H6-H8. a total of five, eight, and six alleles were observed at dyS391. DYS390. and DYS389. re- spectively. The single-step mutation model and a mu- tation rate of 0. 18%(Heyer et al. 1997; Bianchi et al Tibetan▲ Mongolian▲ Ewenki 1998)were used in the estimation. To minimize the pos- sible influence of population substructure on the esti- mation, only Han Chinese samples were included(160 O Lahu M122-C individuals in total). When an effective popu- lation size of 750-2, 000 is assumed(see the material Jao Northern-Han and Methods section), the number of generations esti- Paiwan mated is 919-3, 032 for DYS390, the oldest among all N Amio aTayal Malaysian Southern-Han three estimations. Therefore, the age of M122C is -18,000-60,000 years, if we assume a 20-year gener ation time. We argue that this estimation reflects the age odian o Dong of the bottleneck event leading to the entrance of modern o№ETha humans into eastern Asia, since the extensive presence of the M122-C allele in Southeast Asian populations suggests that this mutation predates their entry It is difficult to accurately date the ancient human migrations(or mutations), because of the errors inher ently involved in estimating both the effective population size of the males and the mutation rate. However, our knowledge of morphology and archaeology can help us ure to narrow the estimated age range. According to the lotype frequencies of 30 eastern-Asian populations. The geographic locations of the populations are shown in figure 1. The triangles refer morphological study by Turner et al. (1993), the so- to northern populations; the circles, to southern populations. This map called Sinodont dentition in northern-Asian peoples oc- accounts for 44% of the original genetic variation

1722 Am. J. Hum. Genet. 65:1718–1724, 1999 Figure 2 Most parsimonious tree of the 17 Y-chromosome hap￾lotypes in eastern-Asian and world populations. The letters “A,” “T,” “G,” and “C” refer to the sequences of those polymorphic loci. The letters “S” and “L” refer to small and large alleles, respectively. The letters “W” and “D” refer to wild-type and deletion alleles, respec￾tively. The underlined letters indicate that the mutations occurred at each locus shown above the branches (for detailed descriptions of mutations, see the Material and Methods section). Figure 3 Principal-component analysis of Y-chromosome hap￾lotype frequencies of 30 eastern-Asian populations. The geographic locations of the populations are shown in figure 1. The triangles refer to northern populations; the circles, to southern populations. This map accounts for 44% of the original genetic variation. they expanded northward to other parts of eastern Asia. A study by Ballinger et al. (1992) also suggested a south￾ern Mongoloid origin of eastern Asians. To estimate the time of the entry of modern humans into eastern Asia, we typed three Y-chromosome micro￾satellite loci for individuals carrying the C allele at locus M122—that is, the allele state shared by Asian-specific haplotypes H6–H8. A total of five, eight, and six alleles were observed at DYS391, DYS390, and DYS389, re￾spectively. The single-step mutation model and a mu￾tation rate of 0.18% (Heyer et al. 1997; Bianchi et al. 1998) were used in the estimation. To minimize the pos￾sible influence of population substructure on the esti￾mation, only Han Chinese samples were included (160 M122-C individuals in total). When an effective popu￾lation size of 750–2,000 is assumed (see the Material and Methods section), the number of generations esti￾mated is 919–3,032 for DYS390, the oldest among all three estimations. Therefore, the age of M122C is ∼18,000–60,000 years, if we assume a 20-year gener￾ation time. We argue that this estimation reflects the age of the bottleneck event leading to the entrance of modern humans into eastern Asia, since the extensive presence of the M122-C allele in Southeast Asian populations suggests that this mutation predates their entry. It is difficult to accurately date the ancient human migrations (or mutations), because of the errors inher￾ently involved in estimating both the effective population size of the males and the mutation rate. However, our knowledge of morphology and archaeology can help us to narrow the estimated age range. According to the morphological study by Turner et al. (1993), the so￾called Sinodont dentition in northern-Asian peoples oc￾curred ∼18,000–25,000 years ago. A similar dentition pattern predominates among all the Southeast Asian populations and was thought to be ancestral to the Sino￾dont pattern. Consequently, this sequence of dental evolution tends to rule out an 18,000-year coloniza￾tion dating—the lower boundary of our age estima￾tion—which was based on an overestimated effective population size. In addition, archaeological evidence from the Altai Mountain and Lake Baikal regions of southeastern Siberia are beginning to show the presence of modern human lithic cultures of 25,000–45,000 years ago (Vasil’ev 1993). Therefore, the first entry of eastern￾Asian populations should predate the emergence of the lithic culture in northern Asia. Recent evidence from archaeological studies indicates that Papua New Guinea was settled ∼35,000–50,000 years ago by modern hu￾mans, aboriginal Australia perhaps even earlierthan that (Brown et al. 1992; Swisher et al. 1996). Hence, if we accept that mainland Southeast Asia is the homeland for all eastern-Asian populations, including Siberian and Oceanian, the upper boundary of the M122-lineage time depth—that is, 60,000 years ago—seems to be a likely estimation of the initial colonization of eastern Asia by modern human populations from Africa. The last Ice Age occurred 75,000–15,000 years ago, although its distribution and the exact date of its pres￾ence in eastern Asia are not clear (Dawson 1992). In-