Scientists found a hominid skeleton that might be changing the theory of human evolution.
“Ardi,” a 110-pound, 4-foot female skeleton, was first discovered in 1994 in Ethiopia’s Afar Rift. Volcanic layers above and below the fossilized skeleton aided researchers in determining the age of Ardi to be about 4.4 million years. Lucy, who had previously been considered the oldest skeleton discovered, would not roam the earth for another million years. The findings were presented in 11 papers published in the journal Science on Thursday.
This discovery of Ardi could possibly reverse the accepted knowledge that humans evolved from chimp-like creatures. Research suggests that instead, humans and chimps evolved from an ancient common ancestor, each species changing differently throughout time. This common ancestor is believed to have lived anywhere from 6 million to 7 million years ago.
But from the research that U anthropology professor Shawn Carlyle has done, he said he believes this discovery does not change that human evolution is somehow connected to that of modern-day apes.
Many of the traits found in Ardi are not shared with modern apes. Rather, she has a mosaic of traits from both humans and apes, said Carlyle, who did not take part in the research involving Ardi. Findings of other fossils of plants and animals near where Ardi was found suggest that those of her species lived in a woodland environment. The species could use all four limbs to climb in trees, but it is believed they did not spend much time there. While on the ground, they could walk upright on two legs, indicated by the position of Ardi’s muscles in the pelvis and hip area. The feet could be used for walking, though they still had a big toe that could be used to grasp tree limbs when climbing.
That’s not to say Carlyle refutes that Ardi doesn’t change anything.
“The big toe is splayed out like thumbs on a human hand,” Carlyle said. “We don’t have any others like that. It really changes how we model bipedality.”
Another key difference in Ardi is the size of her upper canine teeth. Hers were of an intermediate size, stubby like those of modern-day humans, instead of the long, sharp ones characteristic of most primates. In comparison, the canines were relatively small, Carlyle said.
Ardi’s facial features differ from those of a chimpanzee. Although Ardi does have an ape-like appearance because of a projecting muzzle, it is not as defined as those of modern apes. It has also been suggested that her brain was positioned similarly to modern humans from details found at the base of the skull. This could mean certain aspects of visual and spatial perception might have already begun to develop in these early hominids.
“We assume early human models are very chimpanzee-like,” Carlyle said. “This is still an ape. This doesn’t change that.”
