Paternal Population History of East Asia: Sources, Patterns, and Microevolutionary Processes

Asia has served as a focal point for human migration during much of the Late Pleistocene and Holocene. Clarification of East Asia’s role as a source and/or transit point for human dispersals requires that this region’s own settlement history be understood. To this end, we examined variation at 52 polymorphic sites on the nonrecombining portion of the Y chromosome (NRY) in 1,383 unrelated males, representing 25 populations from southern East Asia (SEAS), northern East Asia (NEAS), and central Asia (CAS). The polymorphisms defined 45 global haplogroups, 28 of which were present in these three regions. Although heterozygosity levels were similar in all three regions, the average pairwise difference among haplogroups was noticeably smaller in SEAS. Multidimensional scaling analysis indicated a general separation of SEAS versus NEAS and CAS populations, and analysis of molecular variance produced very different values of Φ(ST) in NEAS and SEAS populations. In spatial autocorrelation analyses, the overall correlogram exhibited a clinal pattern; however, the NEAS populations showed evidence of both isolation by distance and ancient clines, whereas there was no evidence of structure in SEAS populations. Nested cladistic analysis demonstrated that population history events and ongoing demographic processes both contributed to the contrasting patterns of NRY variation in NEAS and SEAS. We conclude that the peopling of East Asia was more complex than earlier models had proposed—that is, a multilayered, multidirectional, and multidisciplinary framework is necessary. For instance, in addition to the previously recognized genetic and dental dispersal signals from SEAS to NEAS populations, CAS has made a significant contribution to the contemporary gene pool of NEAS, and the Sino-Tibetan expansion has left traces of a genetic trail from northern to southern China

Recent Spread of a Y-Chromosomal Lineage in Northern China and Mongolia

We have identified a Y-chromosomal lineage that is unusually frequent in northeastern China and Mongolia, in which a haplotype cluster defined by 15 Y short tandem repeats was carried by ∼3.3% of the males sampled from East Asia. The most recent common ancestor of this lineage lived 590 ± 340 years ago (mean ± SD), and it was detected in Mongolians and six Chinese minority populations. We suggest that the lineage was spread by Qing Dynasty (1644–1912) nobility, who were a privileged elite sharing patrilineal descent from Giocangga (died 1582), the grandfather of Manchu leader Nurhaci, and whose documented members formed ∼0.4% of the minority population by the end of the dynasty

Distribution of Two HIV-1–Resistant Polymorphisms (SDF1-30A and CCR2-64I) in East Asian and World Populations and Its Implication in AIDS Epidemiology

Chemokine receptor CCR2 and stromal-derived factor (SDF-1) are involved in HIV infection and AIDS symptom onset. Recent cohort studies showed that point mutations in these two genes, CCR2-64I and SDF1-3′A, can delay AIDS onset ⩾16 years after seroconversions. The protective effect of CCR2-64I is dominant, whereas that of SDF1-3′A is recessive. SDF1-3′A homozygotes also showed possible protection against HIV-1 infection. In this study, we surveyed the frequency distributions of the two alleles at both loci in world populations, with emphasis on those in east Asia. The CCR2-64I frequencies do not vary significantly in the different continents, having a range of 0.1–0.2 in most populations. A decreasing cline of the CCR2-64I frequency from north to south was observed in east Asia. In contrast, the distribution of SDF1-3′A in world populations varies substantially, and the highest frequency was observed in Oceanian populations. Moreover, an increasing cline of the SDF1-3′A frequency from north to south was observed in east Asia. The relative hazard values were computed to evaluate the risk of AIDS onset on the basis of two-locus genotypes in the east Asian and world populations

Y-Chromosome Evidence for a Northward Migration of Modern Humans into Eastern Asia during the Last Ice Age

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 populations 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, coinciding with the absence of human fossils in eastern Asia, 50,000–100,000 years ago. After the initial peopling, a great northward migration extended into northern China and Siberia

The Genetic Legacy of the Mongols

We have identified a Y-chromosomal lineage with several unusual features. It was found in 16 populations throughout a large region of Asia, stretching from the Pacific to the Caspian Sea, and was present at high frequency: ∼8% of the men in this region carry it, and it thus makes up ∼0.5% of the world total. The pattern of variation within the lineage suggested that it originated in Mongolia ∼1,000 years ago. Such a rapid spread cannot have occurred by chance; it must have been a result of selection. The lineage is carried by likely male-line descendants of Genghis Khan, and we therefore propose that it has spread by a novel form of social selection resulting from their behavior