Science

Australopithecus sediva behaved like humans and apes

Scott A. Williams He is an associate professor of biological anthropology at New York University. Originally featured story conversation.

About 2 million years ago, an ancient human relative, Australopithecus sedivaLives in South Africa today and is near a cave called Malapa. Human cradle.. Until recently, it was not clear how much the seeds spent climbing trees or walking on two legs on the ground.

This was changed by the discovery of the lumbar spine in the lumbar region of a single female Australopithecus sediva, along with other parts of the vertebrae of the same specimen.Scientists from New York University in the United States, the University of the Witwatersrand in South Africa, and 15 other institutions Journal articles It shows Australopithecus sediva I walked like a human, but climbed like an ape. Conversation AfricaNatasha Joseph asked lead author Scott A. Williams about the study and its implications.

What was known Australopithecus sediva Before this study?

Quite a lot.This species was first discovered in 2008 (and Announced in 2010); Since then, the recovery of new fossil material from Malapa has continued. This is because excavations have been conducted since 2008, but large blocks removed from the site were scanned by medical computed tomography (CT) to see if there were any fossils inside. If so, the blocks are prepared to reveal the fossils.

The new lumbar fossil came from one such block, which was removed from a temporary road made by miners many years ago. They blew up the site and used some large blocks to build a mining road. And they were also exploding Hominini fossils.

Two partial skeletal parts (a young male “Kalabo” and an adult female “Issa”) were recovered in the wreckage of the Malapa Cave and outside. So, there are at least two individuals in Malapa, the population of which is less than 2 million years old, they are separate species, Australopithecus Still, the skull, teeth, and skeletal features resembled the members of our genus Homo.very Controversial seed for that reason.

What made you start looking at this particular set of fossils?

I wrote My dissertation About the evolution of the human spinal column, a group that includes us and our closest relatives, apes (chimpanzees, gorillas, orangutans, gibbons).Announcement A. Sediva Published in the meantime, I wrote to Professor Lee Berger. Professor Lee Berger, with his nine-year-old son at the time, discovered that the first fossil remained and asked about the vertebrae found in the figures in the publication. He kindly invited me to work on them, and I’ve been doing that ever since.

we have Already explained Vertebrae recovered by around 2013 and fully published in 2018 Explanation and comparative analysis Of the skeleton.

Initially, we knew about Issa’s spine in the lower thoracic spine, lower lumbar spine, and part of the pelvis. Many of the lumbar vertebrae were missing.

But all the while, new fossils were discovered. And in 2016, a new lumbar spine was prepared. This allowed me to study Issa’s almost perfect waist.

What did the new lumbar spine reveal?

I was able to talk more about Issa’s hips and adaptation to bipedal walking (bipedal walking) than before. In 2013, there were only two of the lowest lumbar vertebrae. From these facts, it was found that the wedge of the bone indicates that Issa is potentially very lordotic (curved forward), in the lumbar region.

With new fossils, more lumbar vertebrae can be included. This balances the estimated curvature with something very similar to the degree of lordosis that modern humans have. In fact, Issa’s bone wedge most closely resembled the average of modern human females. Therefore, Issa was able to reject the previous hypothesis that it was characterized by “hyperlordosis” (the limit of modern human change, or excessive lordosis).

She has shown other clear adaptations to bipedal locomotion, such as the enlargement of inter-articular facets in the lumbar spine. This forms a “pyramidal structure” that allows the upper body to sit down and transfer weight.

However, Issa also has some characteristics that suggest she was a climber. She stood up on a tree and had a strong waist to hang under a branch.Its characteristic mosaic is typical of other body parts A. Sediva Then make sure that the species walked on two legs on the ground, but climbed a tree like an ape.

Does this help find species in the human family tree?

Get closer A. SedivaEvolutionary relationships with other Hominini, whole-body character-based analysis is needed, and we are more and more A. Sediva Every year.Given what this and other studies show, I think it’s a candidate for a close relative of the genus. Homo.. Hopefully Issa’s skull wasn’t destroyed by the miners. Recovering it and other body parts from both her and Karabo will greatly help resolve the debate.

Is there a way for others to study fossils?

New fossils, 3D models of all previously published fossils, and our reconstruction Available online.. Anyone can download, investigate, repeat the analysis, perform their own analysis, or 3D print for educational or other purposes.

The fossils themselves, curated at the University of Witt in South Africa, are also available for research by qualified researchers. The more open the access, the better the science, as individuals with diverse training and backgrounds will undoubtedly make novel observations and move towards a better understanding of human evolution.



https://www.popsci.com/science/human-ancestors-climb-trees/ Australopithecus sediva behaved like humans and apes

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