In 2010, archaeologists discovered the first fossils of Australopithecus sediba, a human-like species that lived in Africa about 1.9 million years ago. Now, extensive analysis shows that these fossils don’t belong to just any old extinct hominids…they might actually represent a direct link in the evolutionary chain of humanity. In other words, a missing link.
The Missing “Missing Link”?
It’s commonly thought that early humans and chimpanzees parted evolutionary ways about five to seven million years ago. The genus Homo proceeded to evolve even further, leading to numerous species and subspecies. Through a process of extinction and introgression, all of these other creatures eventually disappeared, leaving modern man as the sole surviving members of the Homo genus.
But the exact path of human evolution remains a mystery, due to the difficulty in locating ancient transitional fossils (aka missing links). However, its generally accepted that modern humans can trace their lineage back to Homo Erectus, which may have been the first hominid to leave Africa. The ancestors to Homo Erectus are less certain, with scientists taking sides among numerous candidates.
Is Australopithecus Sediba a Missing Link?
In 2010, a team led by Professor Lee Berger announced the discovery of the remains of two early protohumans in South Africa. The bones consisted of an adult female and a boy who most likely died when they fell into an underground cave. The protohumans were dubbed Australopithecus sediba.
After further examination, Professor Berger and his team now believe that this new species, although older than other species typically considered ancestors to Homo Erectus, was actually more advanced in terms of anatomy and likely capabilities. This has led the team to announce that Australopithecus sediba is a more likely candidate for the ancestor for Homo Erectus than the usual suspects. If true, that would make it “on the direct evolutionary line to us.” In other words, it could be a missing link.
“We have examined the critical areas of anatomy that have been used consistently for identifying the uniqueness of human beings. Any one of these features could have evolved separately, but it is highly unlikely that all of them would have evolved together if Australopithecus sediba was not related to our lineage.” ~ Professor Lee Berger, The University of the Witwatersrand
Some of the evidence backing this assertion include:
- Age: The fossils were dated to 1.977 to 1.980 million years ago, making it old enough to be an ancestor to Homo Erectus.
- Brain: While smaller than older fossils, the boy’s brain was probably more similar to modern humans in terms of shape. This may indicate “the start of the reorganization of the brain that would be necessary to make us what we are today.”
- Hand: The adult female’s right hand shares far more in common with modern humans than with apes.
Guerrilla Explorer’s Analysis
So, is Australopithecus sediba a direct ancestor to Homo Erectus and thus, a direct ancestor to us? Is it a missing link? As of this point, scientists aren’t completely convinced. However, many seem to think that it’s a distinct possibility.
“One lineage of Australopithecus almost certainly led into the first member of our own genus called Homo, and from then eventually emerged modern humans. But some of them are side branches, and we’re trying to work out which ones are and which ones aren’t – and that’s why this finding is so important. In many ways, these fossils are the ‘smoking gun’ just before the emergence of our own genus.” ~ Dr. William Harcourt-Smit, American Museum of Natural History