Saturday , April 17 2021

What a fossilized hand says about man’s last ancestors and chimpanzees



The skull of Ardipithecus ramidus at the National Museum of Natural Sciences in Spain.

The skull of Ardipithecus ramidus at the National Museum of Natural Sciences in Spain.
Image: Tia Monte

More than a million years before the early hominin known as Lucy crossed the lesser-known Afar region of Ethiopia Ardipithecus remidus Wander around the same area. Now a team of anthropologists has examined the 4.4 million-year-old fossilized hand One sample (Affectionately nicknamed “Ardi”), arguing that the migration of ancestors may involve more momentum among the trees than previously thought.

Published On Wednesday in the journal Science Advances, the team’s comparative analysis focuses on Ardi’s hand morphology in the context of extinct and found relatives. In conversation with bones from other places in our family tree, the characteristics of Ardi’s hand indicate when specific adaptations that are currently observed in different primates were adapted. Specifically, knowing how Ardi got closer brings us closer to knowing how we (Gay Spines) Became a terrestrial and primary group of primates.

The team of Thomas Cody Frang, a biological anthropologist at A&M University in Texas and the paper’s lead author, noted some key features of Ardie’s hand that indicated how it might move. The phalanges of the specimen were relatively long for its approximate body size. ninthTube bones as well Curved inward, implying that the hand is inclined to grasp. “The fact that Ardipithecus overlaps the length of the fingers and their curvature with the most stressful primates, strongly suggests that Ardipithecus was adapted for suspension,” Frang said.

“Now, that does not mean you know, humans evolved from an ancestor that looked just like a chimpanzee,” he added in a phone call. “This does not mean that chimpanzees are living fossils, or that chimpanzees themselves have not evolved. Instead, our research shows this. Ardipithecus, And apparently, the earliest fossil humans retain characteristics from an ancestor most similar to chimpanzees and bonobos, than to any other living primate. “

Both Ardipithecus and Lucy were found in the Afar region of Ethiopia.

Both Ardipithecus and Lucy were found in the Afar region of Ethiopia.
Image: Wikimedia (fair use)

Originally excavated and described In the early 1990s by a team led by paleo-anthropologist Tim White, Ardipithecus remidus Gained more attention following 2009 Description A partial skeleton (known as Ardi) in the journal Science. White disagrees with the findings of the latest paper, based on the specific bones and specimens selected for surgery, and excluding others.

“We do not dispute the constant 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 achieve the unique anatomy of Ardi’s hand, instead. To use limited and selected measurements in a post-hook argument that supports the unfounded notion that our ancestors were specific chimpanzee-like. “

If you are relatively new to the debate over the nature of human origin and how our ancestors walked or walked among the trees, be prepared to turn around. Back in 2009, White’s team claimed that Hardy lacked characteristics that would indicate that he was fit for a monkey-like life; Such absent features included a morphological array for swaying and climbing trees, and walking on their knuckles. White’s team claimed that the last common ancestor between humans and chimpanzees was probably completely different from any existing monkey.

Frang’s team claims the opposite in this article and stated that the ancestor (who preceded Ardi) was closer to chimpanzees than anything else. They continue to report that more human-like hands first pop up the more well-known ones Australopithecus afarensis, Lucy’s Sex.

The sparsity in the fossil record does not help much, though Ardi’s hand is more complete than that of young Lucy. Frang added that interpretations of Ardi’s hand are helpful in narrowing down the target positions of what the circumstances of her evolution may have been (and by proxy, what arose before and after Ardi).

“This illustrates the point that in science we do not prove something to be true. Instead, we discard hypotheses and alternatives that may be false,” Frang said. “In this case, the hypothesis that humans evolved from an ancestor lacking stress characteristics, and an ancestor that was more like a monkey, I think can be discarded on the basis of Ardipithecus. ”


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