From: Heritage Daily
A newly discovered chromosome places the most recent common ancestor for the Y chromosome lineage more 100,000 years before the oldest known anatomically modern human fossils.
UA geneticists have discovered the oldest known genetic branch of the human Y chromosome – the hereditary factor determining male sex.
The new divergent lineage, which was found in an individual who submitted his DNA to Family Tree DNA, a company specializing in DNA analysis to trace family roots, branched from the Y chromosome tree before the first appearance of anatomically modern humans in the fossil record.
The results are published in the American Journal of Human Genetics: http://www.cell.com/AJHG/abstract/S0002-9297(13)00073-6
“Our analysis indicates this lineage diverged from previously known Y chromosomes about 300,000 ago, a time when anatomically modern humans had not yet evolved,” said Michael Hammer, an associate professor in the University of Arizona’s department of ecology and evolutionary biology and a research scientist at the UA’s Arizona Research Labs. “This pushes back the time the last common Y chromosome ancestor lived by almost 70 percent.”
Read the full article at: heritagedaily.com