A research team from Hunter College in New York , after analyzing numerous human remains that date back to about 4 million years ago, he found the answer:the first walker would have been Ardipithecus ramidus. The first remains of these hominids were discovered in Ethiopia and dated between 5.6 and 4.4 million years ago, and were considered to be among our earliest ancestors.
The first traces of bipedalism were those of famous Lucy , the remains of a female specimen of an Australopithecus afarensis , aged around 18, discovered in 1974 and named after the Beatles song Lucy in the sky with diamonds .
Thanks to its fossil remains and to others found in the same area, researchers have been able to study new details on the evolution of humans, proving that it is from her that we came to Homo sapiens, but also that the human community is identical all over the planet, and that, for humans, speaking of races is scientifically wrong.
They were always from Australopitechus also in the footsteps of Laetoli , the first traces that confirm the new ability, left imprinted in the ash of a volcano.
Previous studies had always argued that when we learned to walk we stopped climbing trees.
The interesting thing that emerges from the research published in Proceedings of the National Academy of Sciences , is that walking on both feet did not prevent climbing on the plants.
It is no coincidence that the hips of the subsequent australopiths ( Lucy and Laetoli ), which had allowed to use the two feet, indicate a progressive weakening of the characteristics that allowed them to secure themselves on the branches.
For walking, two legs are definitely better than four.
And for humans this conquest was of great importance:twice the number of feet resting on the ground corresponds to double the energy expenditure.
California University anthropologist Michael Sockol has calculated that a 50-pound man spends 13 kilocalories to travel one kilometer, while a chimpanzee spends 46.
Walking gave us the opportunity to travel longer distances, but also to free our hands, and to use them to handle tools.
The anatomical changes have been many. The pelvis has become shorter and more rounded, thus providing better leverage to the muscles that move the hips. The angle of the thigh has turned inwards, allowing the feet to align below our center of gravity. The spine has curved in an 'S', bringing the weight to the hips, cushioning the head.
Other important changes concerned the ischium (shorter and more inclined backwards) and the hips, whose muscles could be extended and twisted, also modifying the buttock. In monkeys such as chimpanzees, orangutans and gibbons, the buttock is much smaller than that of humans and does not affect either the hamstrings or the hip.
In humans, however, when the hip flexes, the buttock is activated to compensate for the stretch in the thigh. All this allowed us to support our weight while standing upright.
L’Ardipiteco he had the same ability as us to hyper-extend the hip to walk, but also that of keeping it in the right position when climbing upwards. It remains to be seen whether his feet were still prehensile. But according to scholars this is of little importance:it may have just slowed it down or made it spend a little more energy.
In any case, scholars argue, despite the loss of curved phalanges and extending legs, when we climb rocks and trees we still have an efficiency very similar to that of our relatives.