Evolutionary expert Charles Darwin and others identified the evolutionary closeness of humans, chimps and gorillas based on their shared anatomies, raising some big questions: how do humans co-exist? related to other prime ministers, and just how did people move around early? Research by a Texas A&M University professor may provide some answers.
Thomas Cody Prang, associate professor of anthropology, and colleagues studied the skeletal remains of Ardipithecus ramidus (“Ardi”), dated 4.4 million years old and found in Ethiopia. One of Ardi’s hands was well preserved.
The researchers recently compared the shape of Ardi’s hand with hundreds of other hand samples representing humans, onions and monkeys (measured from bones in museum collections around the world) for comparison. about the type of locomotive behavior used by the earliest hominins (fossil human relatives).
The results give an idea of how early people started walking straight and making similar movements that everyone performs today.
This finding is explained in a study published in the current issue of Advances in science.
“Bone shape reflects changes in specific habits or lifestyles – for example the movement of primates – and by drawing links between bone shape and behavior in living forms, we can make decisions about the behavior of species that extinct, like Ardi, that we can look at directly, Prang said.
“Furthermore, we found evidence for a large evolutionary ‘leap’ between the type of hand Ardi represents and all subsequent hominin hands, including the gender of Lucy (famous skeleton). 3.2 million well-preserved years found in the same area in the 1970s). This ‘evolutionary leap’ occurs at a critical time when hominins transform into a shape more like vertical walking, and the earliest evidence for the manufacture of hominin stone tools and the use of stone tools, such as cutting, is traced animal fossils. “
Prang said Ardi represents an earlier stage in the history of important human evolution as it may shed light on the kind of ancestors from which humans and chimpanzees evolved.
“Our study supports a classical idea first proposed by Charles Darwin in 1871, when he had no fossils or understanding of genetics, that the use of the hands and upper limbs for manipulation in early human relatives associated with straight walking, “he said.” The evolution of human hands and feet may have occurred in a connected way. “
As Ardi is an ancient species, it may retain skeletal features that were present in the last common ancestor of humans and chimpanzees. If this is true, it could help researchers put the origins of the human race – as well as just walking – in a brighter light.
“It may take us one step closer to explaining how and why people developed our form of vertical walking,” Prang said.
He said that the dramatic change in hand anatomy between Ardi and all subsequent hominins occurs at one time, about 4.4 and 3.3 million years ago, coinciding with the earliest evidence of a large toe being lost in human evolution. This is also at the same time as the earliest known stone tools and stone-cut animal fossils.
He said it seems to mark a major change in the lifestyle and behavior of human relatives within this period.
“We recommend that it incorporates an evolution of advanced vertical walking, which allowed human hands to adapt with the evolutionary process for improved manual handling, possibly including stone tools. , “said Prang
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This research was funded by the Wenner Gren Foundation.
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