The missing link hasn’t been found ... because there isn’t one
Wits prof lashes out at those misinterpreting the latest research, emphasises the non-linear nature of our evolution
The problem with Homo sapiens? It’s always dumbing things down into cartoons, caricatures and clever little T-shirts – especially when it comes to its own evolution.
The notion of a “missing link” has fascinated many a child (and some adults) over the decades because it implies we have one direct ancestral line and that we can see in the simplest graphic possible how we evolved over millions of years.
Now a professor at the University of the Witwatersrand is putting the foot on the end of his bipedal body down and saying “no more”.
Lee Berger claims the recent descriptions of Australopithecus sediba are being misinterpreted by some to suggest the “missing link” has finally been found.
But that is not the case. It is the opposite, in fact. As more information comes to light, the non-linear nature of our evolution becomes more obvious.
Berger discovered the fossil site of Malapa in the Cradle of Humankind in August 2008, and it proved to be a treasure trove. It is where one of the biggest “rock stars” in evolutionary studies was found: an adult female and a juvenile male discovered by Berger and his son. The new hominin species to which they belong was later named Australopithecus sediba.
About a decade later, Australopithecus sediba has been named and described in a special issue of the open access journal PaleoAnthropology.
But, as Berger knows all too well, no bones are without contention. And he has lashed out at those who have not only oversimplified the research but done so inaccurately.
“The image of human evolution on T-shirts is incorrect. I would prefer that we forget the term ‘missing link’,” said Berger.
Human evolution was not a linear process in which one species developed into another. Instead, it followed “a process similar to a braided stream, or river delta, where a stream might branch off into its own direction, or later flow back and join a different stream, which might ‘evolve’ into a new species”.
Jeremy DeSilva, a professor of anthropology at Dartmouth who is on the international team that just published its research, said: “The anatomies we are seeing in Australopithecus sediba are forcing us to reassess the pathway by which we became human.”
The special issue containing the research contains nine papers analysing: the skull; vertebral column and thorax; pelvis; upper limb: shoulder, arm and forearm; hand; and lower limb fossils of Australopithecus sediba; along with descriptions of body size and proportions; and walking mechanics, including a 3D computer animation of Australopithecus sediba walking.
The researchers found that Australopithecus sediba is a unique species, disagreeing with earlier critics, according to Wits University.