Human chromosomes
European scientists have determined humanity's "most recent common male ancestor", a person given the name "Y-chromosomal Adam", might have first walked the Earth some 239,000 years ago.
Y-chromosomal Adam is the member of Homo sapiens from whom all living humans are descended patrilineally. In contrast, his female counterpart -- called "Mitochondrial Eve" -- is estimated to have lived from 100,000 to 200,000 years ago
Research by a team of scientists from Iceland has finally placed science's version of Adam and Eve close enough on the evolutionary scale to close yawning gaps in previous theories.
To determine the age of Y-chromosomal Adam, researchers sequenced the genomes of 2,636 Icelanders. This was the largest set ever obtained from a single population, said the Verge.
By so doing, researchers were able to reach a conclusion that humanity's most recent common male ancestor, or the "father" of us all, might have lived between 174,000 and 321,000 years ago. More precisely, the researchers say this Adam probably lived 239,000 years ago.
This new estimate brings the science Adam much closer to the estimate for humanity's most recent common female ancestor that lived about 200,000 years ago.
Before the Icelandic study, the prevailing estimate was that Adam made his appearance 340,000 years ago. Further confusing the issue was a 2013 study that said he lived between 120,000 and 156,000 years ago.
The new study's estimate for the most recent common male ancestor contradicts these and a number of past findings, but does bring the most recent common male and female ancestor closer together in time. Scientists, however, said mitochondrial Eve and Y-chromosomal Adam need not have lived at the same time.
"(Humans) are curious about where we came from, and how we became the way we are," said Agnar Helgason, a genetic anthropologist at the University of Iceland and a co-author of the common ancestor study published today.
"And this gives us a bit more information about when."
Mitochondrial Eve refers to the matrilineal most recent common ancestor in a direct, unbroken, maternal line, of all currently living humans. This is the most recent woman from whom all living humans today descend, in an unbroken line, on their mother's side.
Mitochondrial Eve is estimated to most likely have lived in East Africa when the sub-species "Homo sapiens sapiens" (or anatomically modern humans) were developing as a population distinct from other human sub-species.
A chromosome is a packaged and organized structure containing most of the DNA of a living organism.
