title: An African American paternal lineage adds an extremely ancient root to the human Y chromosome phylogenetic tree.
abstract: We report the discovery of an African American Y chromosome that carries the ancestral state of all SNPs that defined the basal portion of the Y chromosome phylogenetic tree. We sequenced ∼240 kb of this chromosome to identify private, derived mutations on this lineage, which we named A00. We then estimated the time to the most recent common ancestor (TMRCA) for the Y tree as 338 thousand years ago (kya) (95% confidence interval = 237-581 kya). Remarkably, this exceeds current estimates of the mtDNA TMRCA, as well as those of the age of the oldest anatomically modern human fossils. The extremely ancient age combined with the rarity of the A00 lineage, which we also find at very low frequency in central Africa, point to the importance of considering more complex models for the origin of Y chromosome diversity. These models include ancient population structure and the possibility of archaic introgression of Y chromosomes into anatomically modern humans. The A00 lineage was discovered in a large database of consumer samples of African Americans and has not been identified in traditional hunter-gatherer populations from sub-Saharan Africa. This underscores how the stochastic nature of the genealogical process can affect inference from a single locus and warrants caution during the interpretation of the geographic location of divergent branches of the Y chromosome phylogenetic tree for the elucidation of human origins.
authors: Division of Biotechnology, Arizona Research Laboratories, University of Arizona, Tucson, AZ 85721, USA.
authors: Fernando L
authors: FL
authors: Mendez
authors: Thomas
authors: T
authors: Krahn
authors: Bonnie
authors: B
authors: Schrack
authors: Astrid-Maria
authors: AM
authors: Krahn
authors: Krishna R
authors: KR
authors: Veeramah
authors: August E
authors: AE
authors: Woerner
authors: Forka Leypey Mathew
authors: FL
authors: Fomine
authors: Neil
authors: N
authors: Bradman
authors: Mark G
authors: MG
authors: Thomas
authors: Tatiana M
authors: TM
authors: Karafet
authors: Michael F
authors: MF
authors: Hammer
mesh_terms: D017954:Africa South of the Sahara; D000350:Africa, Central; D001741:Black or African American / Q000235:genetics*; D019070:Cell Lineage; D041322:Chromosomes, Human, Y; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D005580:Fossils; D005828:Genetics, Population / Q000379:methods; D006801:Humans; D008297:Male; D010802:Phylogeny; D020641:Polymorphism, Single Nucleotide
chemical_list: D004272:DNA, Mitochondrial