Lucy loved the land, new research suggests. A study in this week’s edition of the journal Science puts forth a foot bone from the early hominid Australopithecus afarensis (Lucy’s kind) as evidence that this species was built for walking—meaning human ancestors could have been striding around on ground level for most of their lives by 3.2 million years ago.
Scientists already knew that A. afarensis could walk on two feet but were unsure whether the creatures climbed and grasped tree branches as well, much like their own ancestor species and modern nonhuman apes. The fourth metatarsal … shows that A. afarensis moved around more like modern humans. “Now that we know Lucy and her relatives had arches in their feet, this affects much of what we know about them, from where they lived to what they ate and how they avoided predators,” said Carol Ward. [The Guardian]
The bone in question comes from Ethiopia, home to many significant hominid finds. And though it is just a small sample, that arched shape in the foot bone suggests Australopithecus had rigid feet, and may not have been much better at climbing trees than you or I.
Arches were an important part of our evolution into humans, because they make climbing trees much harder. The arches on the inside of the foot, nearer to the big toe, serve as a shock absorber when we plant our feet back on the ground. All other living primates have feet made for grasping and bending to hang onto tree branches and their young, more like our hands than our feet. [LiveScience]
Back in August, a study in Nature attempted to push back the date of human ancestors’ first known tool use by 800,000 years—from 2.6 million years ago to 3.4 million years ago. The evidence was a set of scratches on animal bones, which—according to the scientists behind the study—show evidence that the hominid species Australopithecus afarensis used cutting tools.
Not so fast, some anthropologists say. At the time of the Nature paper, researchers including the scientists behind the 2.6-million-year-old find said the newly found markings could have been caused by other means, including trampling by other animals. Now, in a study (in press) for today’s edition of the Proceedings of the National Academy of Sciences, a team of anthropologists makes a full case that the 3.4-million-year-old scratches are not evidence of tool use.
They argue that similar cuts can be produced when bones are gnawed by animals, trampled into rough ground, or even eroded by plants and fungi. Their conclusion: the marks on the Dikika bones were probably created by trampling and their age is uncertain. To them, the best evidence for butchery by human ancestors comes from stone tools recovered in Gona, Ethiopia, which are just 2.6 million years old.
Check out the rest of this post at Not Exactly Rocket Science.
Not Exactly Rocket Science: Human ancestors carved meat with stone tools almost a million years earlier than expected
80beats: Lucy’s Species May Have Used Stone Tools 3.4 Million Years Ago
DISCOVER: How Loyal Was Lucy?
Was Lucy a tool user and a meat eater?
Quite possibly, argues a new study in Nature. Archaeologist Shannon McPherron turned up animal bones at an Ethiopian site that he says show markings of stone tool cutting dating back nearly 3.4 million years. That would be a big jump in the record: Right now the oldest known evidence of tool use among our ancestral species dates back about 2.6 million years.
McPherron’s date falls in the time of Australopithecus afarensis, the species to which the famous Lucy find belongs. But thus far he’s found only the markings on bones—not the tools themselves. Perhaps not surprisingly, though, at least one scientist behind the 2.6 million-year-old find says the new study is not convincing evidence that tool use dates back all the way to 3.4 million years ago.
For plenty more about the find—and the differing opinions—check out DISCOVER blogger Ed Yong’s post.
Not Exactly Rocket Science: Human Ancestors Carved Meat with Stone Tools Almost a Million Years Earlier Than Expected
80beats: Lucy’s New Relative, “Big Man,” May Push Back the Origin of Walking
DISCOVER: How Loyal Was Lucy?
Image: Dikika Research Project
No offense, Lucy, but at three feet, six inches you were kind of short. Your diminutive, 3.2 million-year-old bones made it difficult to tell whether your species could even walk like us. Fortunately, researchers in Ethiopia have uncovered an older, bigger relative. As described in Proceedings of the National Academy of Sciences, some researchers believe that these new bones show that members of Lucy’s species, Australopithecus afarensis, could walk like modern humans.
The paper’s authors call him Kadanuumuu (kah-dah-nuu-muu)–”big man” in the Afar language. Big Man still isn’t really that big by today’s standard: His 3.6 million-year-old bones show that he stood at around five feet.
The fossilized remains don’t include a head, but Big Man has many of the same bones as Lucy, and also others previously missing: a shoulder blade and a rib cage bits. Lead researcher Yohannes Haile-Selassie argues that Big Man’s skeleton upends previous beliefs about Lucy’s love of tree climbing and more primitive walk.
“This individual was fully bipedal and had the ability to walk almost like modern humans,” said Haile-Selassie. “As a result of this discovery, we can now confidently say that ‘Lucy’ and her relatives were almost as proficient walking on two legs as we are, and that the elongation of our legs came earlier in our evolution that previously thought.” [Cleveland Museum of Natural History]