Father of all humankind is 340,000 years old
_http://news.yahoo.com/blogs/sideshow/father-humankind-340-000-years-old-210033011.html
DNA evidence has revealed that the oldest known common male ancestor is 340,000 years old, more than twice as old as previous estimates.
New Scientist reports that the sample comes from a recently deceased man named Albert Perry. After the African-American South Carolina man died, one of his relatives submitted a sample of his DNA to a company called Family Tree DNA for analysis.
The findings were published in the The American Journal of Human Genetics and may require researchers to adjust the known timeline of humankind’s evolution.
And the historical mark came at something of a bargain—the company does historical DNA analysis on individuals for about $150.
All previously compared DNA samples pointed to a common Y chromosome traced back to man who lived between 60,000 and 140,000 years ago. But Perry’s DNA sample broke the trend, not matching up with this common ancestor.
"It's a cool discovery," Jon Wilkins of the Ronin Institute in Montclair, N.J., told New Scientist. "We geneticists have been looking at Y chromosomes about as long as we've been looking at anything. Changing where the root of the Y-chromosome tree is at this point is extremely surprising."
After the initial tests on Perry’s DNA, geneticists at the University of Arizona conducted further tests to confirm the anomaly. The Y chromosome in Perry’s test matched up with those of 11 men who all lived in one village in Cameroon.
University of Arizona researcher Michael Hammer says Perry’s DNA suggests there may have been an earlier species of humans that went extinct—but not before interbreeding with the more modern version of man.
This is the abstract of the paper in question. If you do a search online you may be able to find the actual paper.
An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree
_http://www.cell.com/AJHG/abstract/S0002-9297%2813%2900073-6
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.
The current consensus about the origin of mankind has us tracing our most recent common ancestor via mtDNA to a single woman 160,000 ya and via the Y chromosome to a single man 140,000 ya, known as the basal lineage A1b which the authors of the paper renamed the A0 line. The new findings push the ancestral line back 338,000 ya on the male side which they term the A00 lineage.
The proposed date for the most common ancestor comes close to the Cs date on the origin of the Adamic man some 309,000 ya. The A1b line could then represent the genetic tweaking made at the time, 130,000 ya, to the black peoples. http://www.sott.net/article/250256-The-Cs-Hit-List-09-DNA-Rational-Design-and-the-Origins-of-Life
However, the new paper also gives a new date to the old A1b lineage of some 200,000 ya based on the fact that the previous studies weren't using mutation rates that were based on the whole-genome sequence data that was recently obtained though I think we should still take these dates with a pinch of salt.