More than 1 million years before the early hominin, known as Lucy, crossed the Afar region of Ethiopia, the least known Ardipithecus ramidus roamed about the same area. Now, a team of anthropologists has analyzed the 4.4 million-year-old fossilized hand one copy (affectionately called “Ardi”) and claim that roaming human ancestors could have involved more swinging through trees than previously thought.
Published On Wednesday, in the journal Science Advances, the team’s comparative analysis focuses on the morphology of Ardi’s hand in the context of missing and existing relatives. In the conversation with bones from other parts of our family tree, the features of Ardi’s hand indicate the time when specific adaptations currently observed in different primates appeared. Specifically, knowing how Ardi moved brings us closer to knowing how we will (homo sapiens) became a terrestrial, bipedal bunch of primates.
The team of Thomas Cody Prang, a biological anthropologist at Texas A&M University and the lead author of the recent paper, noticed some key features of Ardi’s hand that indicated how he might have moved. The phalanges of the specimen were long relative to the estimated body size. Those bones as well curved inward, suggesting that the hand was prone to grasping. “The fact that Ardipithecus overlaps in the length and curvature of the fingers with the most suspensive primates strongly implies that Ardipithecus has been adapted to suspension,” Prang said.
“Now, that doesn’t mean that, you know, humans evolved from an ancestor that looked exactly like a chimpanzee,” he added in a phone call. “It doesn’t mean that chimpanzees are living fossils or that chimpanzees themselves have not evolved. Instead, our study shows that Ardipithecus, and probably the first fossil humans retain the characteristics of an ancestor who is more like chimpanzees and bonobos than any other living primate. ”
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Initially excavated and described in the early 1990s by a team led by paleoanthropologist Tim White, Ardipithecus ramidus received more attention after 2009 Description of a partial skeleton (nicknamed Ardi) in the journal Science. White disagrees with the findings of the recent paper, based on the specific bones and specimens selected for analysis and the exclusion of others.
“We do not dispute the well-established fact that the human hand has evolved over time. However, there are no new data or interpretations here, “White wrote in an email. “We cannot take these authors seriously until they deal with the unique anatomy of Ardi’s hand, rather than using limited and selected measurements in a post hoc argument to support the discredited notion that our ancestors were specifically like a chimpanzee ”.
If you are relatively new to the debate over the nature of human origins and how our ancestors might have walked or swayed among the trees, be prepared to spend your time. In 2009, White’s team claimed that Ardi did not have the characteristics to indicate that he was suitable for a monkey-like life; such absent features included a morphological structure to swing among the trees and climb them, and walk on their joints. White’s team claimed that the last common ancestor between humans and chimpanzees was probably quite different from any existing monkey.
Prang’s team claims the opposite in this paper, stating that the ancestor (who preceded Ardi) was closer to the chimpanzees than anything else. He goes on to report that several human-like hands appear first with the most familiar Australopithecus afarensis, Lucy’s species.
The lack of fossil records doesn’t help much, although Ardi’s hand is more complete than the younger Lucy’s. Prang added that Ardi’s hand interpretations are useful in narrowing down the objectives of what could have been the circumstances of his evolution (and, by proxy, what appeared before and after Ardi).
“It illustrates the idea that, in science, we do not prove that something is true. Instead, we eliminate hypotheses and alternatives that could be false, “said Prang. “In this case, the hypothesis that humans evolved from an ancestor who had no suspensive characteristics and an ancestor who was more like a monkey, I think can be thrown on the basis Ardipithecus. ”