Genomic age estimates Settlement of the Americas

recent studies of amerindian genetics have used high resolution analytical techniques applied dna samples modern native americans , asian populations regarded source populations reconstruct development of human y-chromosome dna haplogroups (ydna haplogroups) , human mitochondrial dna haplogroups (mtdna haplogroups) characteristic of native american populations. models of molecular evolution rates used estimate ages @ native american dna lineages branched off parent lineages in asia , deduce ages of demographic events. 1 model based on native american mtdna haplotypes (figure 2) proposes migration beringia occurred between 30k , 25k cal years bp, migration americas occurring around 10k 15k years after isolation of small founding population. model (figure 3) proposes migration beringia occurred approximately 36k cal years bp, followed 20k years of isolation in beringia. yet model proposes migration beringia occurred between 40k , 30k cal years bp, pre-lgm migration americas followed isolation of northern population following closure of ice-free corridor. 3 native american mtdna evolution rate models fall within long chronology theory of migration americas.

a study of diversification of mtdna haplogroups c , d southern siberia , eastern asia, respectively, suggests parent lineage (subhaplogroup d4h) of subhaplogroup d4h3, lineage found among native americans , han chinese, emerged around 20k cal years bp, constraining emergence of d4h3 post-lgm. age estimates based on y-chromosome micro-satellite diversity place origin of american haplogroup q1a3a (y-dna) @ around 10k 15k cal years bp. greater consistency of dna molecular evolution rate models each other , archaeological data may gained use of dated fossil dna calibrate molecular evolution rates.