The oldest “modern” hand could have 1.8 million years – The Point

This is a finger bone discovered in Tanzania that has much to say, it speaks of a human ancestor that had already been equipped with a “modern” hand there are 1.8 million years. A hand that would have allowed all sorts of manipulations. This is the oldest bones of modern hand known to date, says a study published online Tuesday in the British journal Nature Communications . This phalanx was recently discovered on the rich prehistoric site of Olduvai Gorge (northern Tanzania) by a team of researchers led by Manuel Domínguez-Rodrigo, from the Institute of developments in Africa with headquarters in Madrid .

It shows that the owner of this phalanx, an adult called OH 86 coexisted there with the Paranthropus boisei – a robust Australopithecus – Homo habilis and with the (“clever man”) who knew make primitive tools of stone. OH 86 could be an ancestor of Homo erectus (“upright man”) or a Homo erectus fossil representative of the genus Homo (there appeared about 1.7 million years, Ed), argues Mr. Dominguez- Rodrigo.

If researchers are enthusiastic about the piece of bone, it is because the hand is one of the most important anatomical features of the human species. “Our hand has evolved to allow us all sorts of gestures and manipulations, more than any other primate,” explains Dominguez-Rodrigo. “It is this ability to precisely manipulate that interacted with our brain and allowed the development of our intelligence, mainly thanks to the invention and use of tools,” he adds. When hominids stopped moving on all fours to become bipeds there are about six million years, that released their hands. The thumb has evolved, he grew up. But the phalanges of the hand of hominids are clearly curved, helping them to climb trees.

A large hunter?

Four million years later, phalanges of the ancestor of man are recovering, a sign that life in the trees is no longer appropriate. “The hands are freed from locomotion in trees and can specialize in handling,” says the researcher. The first stone tools are emerging to 2.6 million years. The small phalanx straight 36 millimeters long – the same size as that of Homo Sapiens – found at Olduvai “fills a gap: we discovered that this hand modern appearance dates at least 1.85 million years, “says Dominguez-Rodrigo.

” This discovery also shows that this creature was larger hominid no previous or contemporary. His hand is that of a man who was to be more than 1 m 75, “says the researcher. OH 86 may have been able to hunt large animals and to transport their heavy carcasses, such as those that have been found including Olduvai and could weigh up to 350 kilos. “I’ve always wondered how Homo habilis, which measured just over one meter, could also hunt large animals. OH 86 is a better candidate for explaining these accumulations of carcasses, “he said.

But some scientists believe that the researcher goes too far in its conclusions. “A single phalanx straighter, a little finger does not mean that the entire skeleton resembled that of a modern man,” says Tracy Kivell, an anthropologist at the University of Kent (UK) . Others highlight the interest of the study. “It returns the balance to Africa regarding the origin of” real humans “there are 1.9 million years,” says Jean-Jacques Hublin of the Max Planck Institute for the Study of Anthropology (Germany). “It also provides arguments” to those who doubt that Homo habilis is that manufactured stone tools found in the area and from that period, he said.