‘Lucy’ walked on two feet with human ancestors 3.2 mn-yrs ago
By ANIFriday, February 11, 2011
WASHINGTON - A new study has found that ‘Lucy’ or Australopithecus afarensis, a species that lived more than three million years ago, walked on two feets just like Homo Sapiens.
The University of Missouri and Arizona State University study could change scientists’ views of human evolution.
Carol Ward, an MU researcher and William Kimbel and Donald Johanson of the Institute of Human Origins at Arizona State University, studied a 3.2 million-year-old fourth metatarsal of Australopithecus afarensis.
A team from the Institute of Human Origins and National Museum of Ethiopia led by Kimbel discovered the fossil in Hadar, Ethiopia.
The foot bone suggested that these hominids had stiff, arched feet, similar to humans. Australopithecus afarensis had smaller brains and stronger jaws than humans, and scientists have known the animals walked upright on two feet.
However, researchers have not known whether Lucy and her kin were more versatile creatures than humans and spent time climbing through the trees.
“Now that we know Lucy and her relatives had arches in their feet, this affects much of we know about them, from where they lived to what they ate and how they avoided predators.
“The development of arched feet was a fundamental shift toward the human condition, because it meant giving up the ability to use the big toe for grasping branches, signaling that our ancestors had finally abandoned life in the trees in favor of life on the ground,” said Ward.
With human-like arches in its feet, Australopithecus afarensis was able to roam the countryside and leave the forest to forage for food when necessary.
Combining their strong jaws and their new skill of walking, Lucy and her relatives were able to live in open areas as well as wooded ones.
“Understanding that the arch appeared very early in our evolution shows that the unique structure of our feet is fundamental to human locomotion. If we can understand what we were designed to do and the natural selection that shaped the human skeleton, we can gain insight into how our skeletons work today. Arches in our feet were just as important for our ancestors as they are for us,” added Ward.
The study has been published in Science. (ANI)