Biology subjects

Vilar, M. G.

Publications and source records attributed to Vilar, M. G..

3 recordsLinked to original sources

bioRxiv2026

Mitotree: The Universal Human Mitochondrial Reference Phylogeny at 10x the Resolution

Mitochondrial DNA (mtDNA) is the oldest and most prevalent source of human molecular phylogenetic reconstruction. Everyone alive today traces their matrilines to one female African ancestor who lived some 145 thousand years ago. For decades, PhyloTree provided researchers with a moderately sized reference tree (v17: n=24,275 sequences, n=5,438 branches). However, hundreds of thousands of sequences are available today, and since PhyloTrees retirement in 2016, there is a need for an actively maintained phylogenetic reference system. In addition, no currently published method can wield such a large de novo reconstruction while dealing with the rampant homoplasy seen in mtDNA and adhering to the accuracy standards expected in this well-studied field. In this paper we introduce Mitotree, the largest human phylogeny ever described (n{approx}330,000 complete sequences, n{approx}54,000 branches), and a new recursive phylogenetic pipeline for estimating it. We incorporate ancient DNA, relaxed clock age estimates (TMRCAs), and public databases (e.g., GenBank, 1000 Genomes, HGDP, and SGDP). We report approximately 180 previously unknown branches older than 30,000 years. The median TMRCA of terminal haplogroups is 2,000 years more recent than PhyloTree. Our pipeline offers a novel divide-and-conquer approach that tackles huge heuristic searches within tractable runtimes, provides high accuracy, and reasonable confidence estimates. Our validation found a false negative rate of 3.5%, and a false positive rate of 1.0%. Among the most striking findings are an [~]83 kya split of African L2e (the oldest in our dataset), the resolution of Otzis K1f into a clade with living descendants, new ethnic founder haplogroups (e.g., Jewish diaspora), and placement of historical figures such as Abraham Lincoln. To our knowledge, Mitotree is the largest de novo haplotype phylogeny built for humanity, and is a continually improved resource for academic, genealogical, and medical research.

genetics↗

bioRxiv2026

Genetic Basis of Social Structure in the Pastoral Nomads of Central Eurasia

Although the social structure of Central Eurasian pastoral nomads has been described as fluid and ad hoc by historians and anthropologists, its potential genetic basis remains poorly understood. To evaluate whether kinship based social organization has biological foundations, we surveyed Kazak populations in Jetisuu, Kazakstan, for genomic diversity with special reference to their kinship structure. We generated genome-wide SNP data ([~]750K) using GenoChip microarrays for 80 individuals from four Kazak clans in Jetisuu and 10 Kazaks from other regions. Our results reveal substantial concordance between genetic and genealogical data, with [~]64% of Jetisuu Kazaks sharing the same Y-chromosome haplotype, indicating they have a common paternal ancestry aligning with clan genealogies. By contrast, maternal lineages show remarkable heterogeneity, thereby reflecting female exogamy. Despite this sex-biased admixture pattern, autosomal SNPs reveal no pronounced population structure in Kazaks, suggesting genetic homogenization through ancient admixture followed by continuous gene flow between Kazak populations. Notably, Jetisuu Kazaks exhibit significantly reduced levels of runs of homozygosity (ROH) compared to their sedentary neighbors such as Turkmens, Tajiks, Uyghurs, and Uzbeks. This genomic signature likely results from clan exogamy, which functions as a biological mechanism to prevent inbreeding and maintain genetic diversity. Our findings demonstrate that nomadic social organization represents a sophisticated example of gene-culture co-evolution, where cultural practices have systematically shaped genetic patterns over centuries. These data provide new insights into historical pastoral nomadic societies and offer a nuanced perspective on anthropological debates about kinship authenticity in Central Eurasian nomads.

genetics↗

bioRxiv2019

Population histories of the United States revealed through fine-scale migration and haplotype analysis

The population of the United States is shaped by centuries of migration, isolation, growth, and admixture between ancestors of global origins. Here, we assemble a comprehensive view of recent population history by studying the ancestry and population structure of over 32,000 individuals in the US using genetic, ancestral birth origin, and geographic data from the National Geographic Genographic Project. We identify migration routes and barriers that reflect historical demographic events. We also uncover the spatial patterns of relatedness in subpopulations through the combination of haplotype clustering, ancestral birth origin analysis, and local ancestry inference. Examples of these patterns include substantial substructure and heterogeneity in Hispanics/Latinos, isolation-by-distance in African Americans, elevated levels of relatedness and homozygosity in Asian immigrants, and fine-scale structure in European descents. Taken together, our results provide detailed insights into the genetic structure and demographic history of the diverse US population.

genetics↗