Four Million Year Old Skull Unlocks Some of the Mystery of Human Life
Scientists have been able to answer some long-standing questions by virtually reconstructing the brain case of a four-million-year-old human relative.
The researchers found the fossilized cranium was composed of the spongy bone found in our own skulls. However, when they studied other types of hominin skulls they found it displayed striking differences. The research was published in the Journal of Human Evolution.
Study author and University of the Witwatersrand scientist Amélie Beaudet said in a statement that this large portion of spongy bone, also found in our own cranium, may indicate that blood flow in the brain of Australopithecus may have been comparable to us, and/or that the brain case had an important role in the protection of the evolving brain.
The ancient skull fragments belonged to a member of the Australopithecus group—an extinct hominin family which scientists believe led to our own genus: Homo. Modern humans are known as Homo sapiens.
The broken braincase was first excavated in the Jacovec Cavern in the Sterkfontein Caves close to Johannesburg in South Africa. Even though scientists have examined the specimen for many, many years, its fragmentary nature has limited their results. But now, according to the scientists advanced “virtual paleontology” imaging has enabled them to look inside the bones in precise detail.
Beaudet explained that their study revealed that the cranium of the Jacovec specimen and of the Ausralopithecus specimens from Sterkfontein, in general, was thick and essentially composed of spongy bone. Adding that this large portion of spongy bone, also found in our own cranium, may indicate that blood flow in the brain of Australopithecus may have been comparable to us, and/or that the brain case had an important role in the protection of the evolving brain.
The team also realized that the skull material was different to some other ancient hominin heads that had been analyzed. The cranium of distant human relative Paranthropus—who lived less than two million years ago—was thinner and composed of more compact bone. Beaudet remarked that this result is of particular interest because it may suggest a different biology.
Beaudet also explained that the four-million-year-old bone fragments offer scientists a unique chance to learn more about the biology and diversity of our ancestors and their relatives and, ultimately, about their evolution.
This is the most recent find to expand scientific understanding of our ancestors. New studies have cast light on the diets of our forebears. Scientists think ancient hunter-gatherers may have snacked on jerky, while Vikings appear to have feasted on raw fish and tapeworms.
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