Analysis of information sources in references of the Wikipedia article "Classification of the Indigenous peoples of the Americas" in English language version.
The relatively lower coalescence time of the entire haplogroup A2 including the shared sub-arctic branches A2b (Siberians and Inuit) and A2a (Eskimos and Na-Dené) is probably due to secondary expansions of haplogroup A2 from the Beringia area, which would have averaged the overall internal variation of haplogroup A2 in North America.
Archaeological evidence, in fact, recognizes that people started to leave Beringia for the New World around 40,000 years ago, but rapid expansion into North America didn't occur until about 15,000 years ago, when the ice had literally brokenpage 2 Archived March 13, 2012, at the Wayback Machine
Haplogroups are defined by unique mutation events such as single nucleotide polymorphisms, or SNPs. These SNPs mark the branch of a haplogroup, and indicate that all descendants of that haplogroup at one time shared a common ancestor. The Y-DNA SNP mutations were passed from father to son over thousands of years. Over time, additional SNPs occur within a haplogroup, leading to new lineages. These new lineages are considered subclades of the haplogroup. Each time a new mutation occurs, there is a new branch in the haplogroup, and therefore a new subclade. Haplogroup Q, possibly the youngest of the 20 Y-chromosome haplogroups, originated with the SNP mutation M242 in a man from Haplogroup P that likely lived in Siberia approximately 15,000 to 20,000 years before present
{{cite web}}: |author= has generic name (help)The divergence time for the Nadene portion of the HaeIII np 663 lineage was about 6,000–10,000 years. Hence, the ancestral Nadene migrated from Asia independently and considerably more recently than the progenitors of the Amerinds
Over time descendants developed a unique culture—one that was different from the original migrants' way of life in Asia but which contained seeds of the new cultures that would eventually appear throughout the Americas
Haplogroups are defined by unique mutation events such as single nucleotide polymorphisms, or SNPs. These SNPs mark the branch of a haplogroup, and indicate that all descendants of that haplogroup at one time shared a common ancestor. The Y-DNA SNP mutations were passed from father to son over thousands of years. Over time, additional SNPs occur within a haplogroup, leading to new lineages. These new lineages are considered subclades of the haplogroup. Each time a new mutation occurs, there is a new branch in the haplogroup, and therefore a new subclade. Haplogroup Q, possibly the youngest of the 20 Y-chromosome haplogroups, originated with the SNP mutation M242 in a man from Haplogroup P that likely lived in Siberia approximately 15,000 to 20,000 years before present
{{cite web}}: |author= has generic name (help)Archaeological evidence, in fact, recognizes that people started to leave Beringia for the New World around 40,000 years ago, but rapid expansion into North America didn't occur until about 15,000 years ago, when the ice had literally brokenpage 2 Archived March 13, 2012, at the Wayback Machine
Over time descendants developed a unique culture—one that was different from the original migrants' way of life in Asia but which contained seeds of the new cultures that would eventually appear throughout the Americas
The relatively lower coalescence time of the entire haplogroup A2 including the shared sub-arctic branches A2b (Siberians and Inuit) and A2a (Eskimos and Na-Dené) is probably due to secondary expansions of haplogroup A2 from the Beringia area, which would have averaged the overall internal variation of haplogroup A2 in North America.
The divergence time for the Nadene portion of the HaeIII np 663 lineage was about 6,000–10,000 years. Hence, the ancestral Nadene migrated from Asia independently and considerably more recently than the progenitors of the Amerinds