LEICESTER, England, Feb. 25 (UPI) -- DNA analysis has revealed a common ancestor -- or genetic "Adam," a biblical reference -- of all chimpanzees and bonobos.
The original chimpanzee lived more than 1 million years ago and now sits atop the family tree.
Scientists at the University of Leicester traced a section of the Y chromosome passed from fathers to sons among a group of chimps, bonobos, gorillas and orangutans. Researchers also traced mitochondrial DNA passed from mothers to their offspring.
The analysis allowed researchers to fill out the genealogical tree and place a genetic Adam at the top. Researchers published their findings in the journal Genome Research.
"The ancestor of a Y-chromosome family tree is sometimes called 'Y-chromosomal Adam,'" lead study author Pille Hallast, a geneticist at Leicester, said in a press release.
The genetic Adam of humans is 200,000 years old; gorillas' Adam is only 100,000 years old.
"The Y chromosome tree for gorillas is very shallow, which fits with the idea that very few male gorillas -- alpha males -- father the offspring within groups," explained Hallast. "By contrast, the trees in chimpanzees and bonobos are very deep, which fits with the idea that males and females mate with each other more indiscriminately."