Mesoamerica is a cultural and geographic region with a northern boundary adjacent to the American Greater Southwest and a southeastern boundary that includes the Maya area, which is adjacent to the Caribbean. These regions are of interest to analyze genetic structure, ancestry, and gene flow between the ancient populations. We identified the mitochondrial DNA haplogroups and haplotypes in 19 colonial and 10 pre-Columbian Maya from Xcaret and 6 Paquimé individuals. We analyzed our data together with 603 ancient individuals and with 95 colonial and 502 pre-Columbian individuals. The results show clear genetic differences among Mesoamerica, American Greater Southwest, and Caribbean regions. High frequency of haplogroup A in Paquimé and Mine Canyon and the distribution of its haplotypes in the networks suggest these populations are probably genetically related with both Mesoamerican and the American Greater Southwest populations. The genetic structure of the Maya is due to common ancestry, and it was maintained by geographic isolation and gene flow mostly between Mayan populations. The Spanish conquest did not change this structure in the Maya from Xcaret, Quintana Roo. Although populations from Central Mexico are not genetically homogeneous, they are clearly different from Maya. Teotihuacan and Cholula were contemporary cities that allied to control the region, but they show genetic differences that could be related to a distant common ancestry; they probably descended from the same group but separated very early, before their arrival in Central Mexico.

The Hakka, who have undergone a series of great migrations, are usually identified with people who speak the Hakka language or share at least same Hakka ancestry. As the largest Hakka dialect island in West China, the Dongshan region was closely linked with the great migration wave of Hakka. However, the paternal genetic profiles of Dongshan Hakka have never been revealed. In the present study, 41 Y-chromosomal short tandem repeat (Y-STR) loci included in the SureID PathFinder Plus Kit were analyzed in 353 unrelated male individuals (171 Hakka and 182 Han) of Sichuan Province, China. By analyzing 166 different haplotypes among Dongshan Hakka and 176 different haplotypes among Sichuan Han males, haplotype diversity was calculated as 0.9997, with a discrimination capacity of 0.9708, for the Hakka population, and 0.9996 and 0.9670 for the Sichuan Han population, respectively. Most of the Y-STR loci were highly informative in both populations except DYS645. The genetic relationships were evaluated by comparing the Hakka population with 11 other groups that are relevant to Hakka migration routes. The results of the multidimensional scaling plot and phylogenetic tree indicate that the Dongshan Hakka population was closely related to Han nationalities from Anhui, Jiangxi, and Fujian Provinces.

The activities of Mongolic-speaking populations, a large group of people in eastern Eurasia, have important impacts on the history of East Asia and other parts of Eurasia. Most previous genetic research of East Asian populations, including ancient DNA studies, has involved samples from Mongolic-speaking populations or their ancient relatives. This review summarizes frequency data of paternal Y-chromosome haplogroups from all available literature about Mongolic-speaking populations from 1999 to 2019. Fourteen paternal components were identified, and six of them are proposed as major and common components in ancestor groups of Mongolic-speaking populations. The article thoroughly discusses the possible origin, migration patterns, and the roles of these six components in the evolutionary history of Mongolic-speaking populations, as well as implications of present achievements in human genetics for future multidisciplinary research in ethnology, history, archaeology, and linguistics.

Ancient human genome data accumulated in recent years can be employed to establish the spatiotemporal trajectories of genetic variants associated with human diseases. Such knowledge might illuminate if and how past adaptations impact contemporary human health and medicine. Scarcely any studies have yet attempted to evaluate genetic susceptibility to neurodegenerative disorders in ancient human communities. Using publicly available ancient human genome-wide data, this study evaluated the molecular predisposition to neurodegenerative disorders in ancient human communities. Ancient genome-wide data was screened for the presence of variants unequivocally associated with neurodegenerative disorders in modern populations, identifying two rare variants in the LRRK2 gene associated with Mendelian Parkinson's disease, a pathogenic variant in the CRH gene associated with an uncommon form of epilepsy, and a rare variant in the TREM2 gene that is a possible risk modifier associated with Alzheimer's disease. Their historical and geographic prevalence was also assessed, indicating differing spatiotemporal frequency dynamics for these clinically significant variants. Neurodegenerative disorders often have poorly understood pathogenesis that might be elucidated by studying the interaction of past genetic variability with ecological and evolutionary factors such as adverse environmental conditions, specific selective pressures, periods of population isolation, and admixture processes. Data on molecular predisposition to neurodegenerative disorders in ancient genomes is instructive to modern medical diagnostic and therapeutic practices.