According to the University of the Witwatersrand, three new papers have confirmed that autralopithecus sediba was in fact a distinct species.
All three papers have been published in the open access journal PaleoAnthropology, along with an introduction focusing on sediba.
The fossils were first found in the Cradle of Humankind in August of 2008. At the time some criticisms were raised as to whether sediba was in fact a different species.
The new research focused on the anatomy of Sediba, with the first looking at sediba’s skull.
Like other australopiths, according to the research abstract it had:
…small brain size, marked glabellar block, robust zygomatics with steeply inclined zygomaticoalveolar crest, degree of prognathism, patent premaxillary suture, topography of the entrance to the nasal cavity and the insertion of vomer, and narrow palate.
But it also had features in common with early humans, including:
…limited postorbital constriction, widely spaced temporal lines, medially positioned mandibular fossa, moderately-defined supraorbital torus and supratoral sulcus with expanded supraorbital trigon, unflared zygomatics, anterolaterally oriented lateral orbital margins, anteriorly positioned anterior nasal tubercle, raised intermaxillary suture, small mandibular symphysis and corpus, well excavated subalveolar fossa, steeply inclined lingual alveolar plane, and weak superior transverse torus with absent inferior transverse torus.
So because it is this mishmash of features from australopith and homo lines, the researchers favour the idea that it may have been an ancestor.
The next study looked at the ribs, vertebrae and sternum of sediba.
Now the question here was, there were two partial fossils, were they the same species? The first fossil’s lumbar vertebrae looked like they belonged to a species of homo, and the second looked like Australopithecus.
What the researchers found, however, on closer examination was that this was actually just because the first fossil was a juvenile, and had lot of growing up to do.
The third study looked at sediba’s shoulder, arm and forearm.
What they found was that sediba was that they arms were pretty primitive, and thus pretty good at climbing and hanging suspended from trees.
Now the thing is – does this all mean that sediba was the “Missing link”?
Well, Lee Berger, the guy credited with the discovery of sediba isn’t a fan of that particular phrase.
You see the thing is evolution isn’t a straight line, it is a branching and twisting path where you have things diverge, converge and sometimes split off completely on their own.
Berger explains further in this video from Wits:
One of the things that I always feel is a pity in South Africa is that we don’t do more to fund science education in our schools.
And that is because as a country, when it comes to science we’re pretty good at it. We don’t release a lot, but what we do release tends to be top notch work.
And sediba is one of those the examples of that – solid work that is slowly leading to a new understanding of where our species came from.
Imagine what we could do if we took the sciences seriously, and properly funded science education in our schools?
If we increased funding for scientific research, setting up new labs and projects to hire scientifically minded students, and have them attain careers as researchers and investigators, how much could we as a country change the world’s understanding of so much else?
Far too much of what has gone wrong in South Africa is that we have accepted that we are the third world, and we accept a standard far below what we can attain.
And that is a lot of my anger over politics, and petty division right there – that I understand that we can achieve so much if we are just willing to decide to do it.
- Picture courtesy of Professor Lee Berger and Wits university via Wikimedia Commons.