Newly discovered 1.42 Million-Year-Old Bone shows that human hand evolved much earlier than previously believed, researchers have said.
The anatomy of the hand gives humans an edge over other apes when it comes to tool making. But, lack of ancient bones makes it nearly impossible for researchers to determine when modern humans evolved distinctive hand anatomy.
Now, a team of researchers have found a human bone that is about 1.42 million years old. The hand bone shows that humans evolved complex hand design about half a million years earlier than previously assumed.
The bone was discovered by Fredrick Kyalo Manthi of the National Museums of Kenya at the Kaitio site in Kenya and analyzed by researchers including those from University of Missouri, Smithsonian Institution and the University of Utah. The team suspects that the bone belongs to the Homo erectus, the oldest known humans.
"This bone is the third metacarpal in the hand, which connects to the middle finger. It was discovered at the 'Kaitio' site in West Turkana, Kenya," said Carol Ward, professor of pathology and anatomical sciences at MU, according to a news release. "What makes this bone so distinct is that the presence of a styloid process, or projection of bone, at the end that connects to the wrist. Until now, this styloid process has been found only in us, Neandertals and other archaic humans.
The styloid process helps dexterity and precision, which enables humans to make complex tools.
"There's still a huge gap in our understanding of the evolution of the hand," J. Michael Plavcan, professor of anthropology at the University of Arkansas, according to a news release. "We need to find even earlier bones to determine just when structural features of the hand appeared."