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.
Evidence for an earlier common genetic ancestry--i.e. evidence for an earlier time to MRCA (TMRCA, time to most recent common ancestor, a.k.a. the time to Y-chromosomal Adam)--has been growing. See Dienekes' Anthropology blog's post on May 20, 2011, "The father of us all: 142 thousand years ago." The estimate of 142,000 years ago was itself was a far cry from the then widely disseminated estimate of 60,000 years years ago.
Nothing like being more than 400% off, huh? Well, that's in part how science works: hopefully cumulatively increased precision and understanding attained by increments of new knowledge and refinements of knowledge and occasional massive leaps, and with no guarantee--it might be added--that some of those increments along the way may be a step backward. But, it's the net result of all the efforts/findings (the increments) along the way that matters. 142,000 years ago or 340,000 years ago.... It's not that the difference doesn't matter, but the difference has a significance that's profoundly minor in light of greater reality they're addressing: the story of us all.
(Photo: An X and a Y chromosome. Univ. of Arizona.)