The age and location of these fossils strengthen the view that the human and the modern ape lines originated in Africa and not Asia, the researchers said.More pieces to the puzzle. The other mystery, of course, is when the last common ancestor of humans and chimpanzees lived.
"Until now, no mammalian fossils south of the Sahara have been securely dated to 8 million to 9 million years ago," Suwa said. "Any and all fossils from this crucial time period of Africa would help unravel the story of human origins and emergence. These are the first such fossils."
In addition, until recently, "most scientists, especially geneticists, thought that the human-chimp split was as recent as 5 million years ago, and that the human-gorilla split was only about 7 million to 8 million years ago," Suwa said. "This contradicted the fossil record. For example, fossils thought to be on the human side of the split such as Ardipithecus kadabba from Ethiopia and Sahelanthropus from Chad were 6 million years old — or, in the case of the Chad fossil, perhaps 7 million years old."
The new findings suggest that Chororapithecus is 8 million years old, so "the actual gorilla-human split must then have been up to several million years before that," Suwa said.
Thursday, February 25, 2016
Human/Gorilla Split at Eight MYA?
Scientific American is running an article, which details work by Gen Suwa and colleagues, in the Afar Triangle, where nine gorilla-sized teeth were found in 2007 that have now been securely dated to around eight million years ago. The researchers named the species Chororopithecus abyssinicus. Charles Choi writes: