… says Christian Science Monitor:
Thousands of years ago, somewhere in Africa, lived a man who – probably – had no idea that he, among all the other men in his group, would go on to become humankind’s most recent common male ancestor. Scientists would call him “Adam.”
Now, a new paper published in the journal Science significantly narrows the time during which Adam could have lived – about 120,000 to 156,000 years ago – putting him in about the same time period as humankind’s most recent common female ancestor, often dubbed “Eve.” The research revises previous findings that dated Adam within a much longer period.
And the findings also ease recent doubts that the Y chromosome can reliably trace ancient lineage, renewing confidence that tracing and dating lineage using mutations in the Y chromosome could be critical in answering some of the vexing questions about how and where the first humans originated.
Here’s the paper:
Sequencing Y Chromosomes Resolves Discrepancy in Time to Common Ancestor of Males Versus Females
The Y chromosome and the mitochondrial genome have been used to estimate when the common patrilineal and matrilineal ancestors of humans lived. We sequenced the genomes of 69 males from nine populations, including two in which we find basal branches of the Y-chromosome tree. We identify ancient phylogenetic structure within African haplogroups and resolve a long-standing ambiguity deep within the tree. Applying equivalent methodologies to the Y chromosome and the mitochondrial genome, we estimate the time to the most recent common ancestor (TMRCA) of the Y chromosome to be 120 to 156 thousand years and the mitochondrial genome TMRCA to be 99 to 148 thousand years. Our findings suggest that, contrary to previous claims, male lineages do not coalesce significantly more recently than female lineages.
Thoughts?
They’re using a mtDNA mutation rate of “2.3 × 10^?8 /bp/year” based on radiometric dating of human migrations, which is 54 times slower than the observed mtDNA mutation rate of “1.24 × 10^-6, per site per year” that we consistently get from pedigree studies.
Using the observed rate would put mtEve at only a few thousand years ago, instead of the 99-148 thousand years ago they propose. I don’t know which is correct.
assumption junction what’s your gumption?
I wonder how they dealt with the ‘Noah bottleneck’:
Ah JoeCoder just read your post at 1, thanks, these new results are thus duly taken with a grain of salt!
@BA77 on #3
Dr. Carter considers the ancient date of Y Adam to be an unsolved problem, and I’ve never seen Fuz Rana mentioned that the observed rate of mtDNA mutations contradict his own dates. Either the radiometric dates or the molecular clocks have to be grossly incorrect. I don’t know which.
Semi OT: “Does the rock and fossil record speak of Noah’s flood or evolution?” – debate
In a lively debate Young Earth Creationist Andy McIntosh & paleontologist Robert Asher joined me on the most recent show.
listen at
http://bit.ly/171dSf9
Of note, I side on the Old Earth side, but am impressed at the amount of evidence for something catastrophic happening fairly recently worldwide