DNA Studies

Who Crossed the Bering Land Bridge?

Blaine Bettinger 4 Comments

dna2.jpgHow many founding Asian groups braved their way across the Bering land bridge during those frigid Pleistocene ice ages?Was it a single wave of people who later developed into the three distinct linguistic and cultural groups that populated the Americas, or were there multiple waves of people each with their own language and culture? Or was it some mix of the two?The issue has been and continues to be a topic of debate.

Linguistic studies of the Na-dene, Aleut-Eskimo, and Amerind language groups suggested that there were three waves across the land bridge, one for each language group.Recent genetic research, however, has suggested that there was only a single wave of founding groups into the Americas. (Read a free online review here). ... Click to read more!

MITOMAP Publishes an Updated mtDNA Phylogenetic Tree

Blaine Bettinger 3 Comments

MITOMAP, the human mitochondrial genome database, has recently published a paper in Nucleic Acids Research (Free Full Text Here) announcing the completion of a full human mtDNA phylogenetic tree.

This tree, available here(pdf) was constructed from 2959 mtDNA coding region sequences (using the rCRS as the reference).In addition to listing mutations and the study that identified each particular sequence, the tree labels each mutation as a substitution mutation, a silent mutation, a tRNA or rRNA mutation, a mutation in the noncoding region, or a pathological mutation.MITOMAP also provides another valuable tool, tables of mtDNA polymorphisms with source information.

The tree will potentially be very useful to both researchers and genetic genealogists by providing a quick and easy way to characterize new sequences.Anyone interested in learning more about their haplogroup or how their haplogroup fits into the human mtDNA tree will find the new mtDNA phylogenetic tree extremely informative. ... Click to read more!

New estimates for the arrival of the earliest Native Americans

Blaine Bettinger 4 Comments

 

Scientists have analyzed the mitochondrial and Y-chromosomal DNA from a 10,300-year-old human remains found in On Your Knees Cave on Prince of Wales Island in Alaska.These remains, the oldest human remains known from Alaska or Canada are from a young man in his early twenties.

DNA sequencing showed that the individual’s mitochondrial DNA belongs to an ancient subhaplogroup of haplogroup D that was brought to the Americas rather than mutating from haplogroup D once it arrived in the Americas.Interestingly, a sample of almost 3,500 Native Americans revealed that only 1.5% belonged to the same subhaplogroup of D (characterized by 16223T, 16342C, and 16241G).Those that did were found mostly along the Pacific coast of North and South America. ... Click to read more!