This week we enter the final stages of our journey, moving from the transitional hominins safely into the early members of our own genus Homo. Again, some controversy exists over whether to split the earliest accepted members of our genus into Homo ergaster in Africa and H. erectus in Asia, or whether to lump them both into H. erectus. Personally, I prefer lumping to splitting in this case – H. erectus it is.
A lot of excitement surrounds the ‘transitional’ hominins as these are the members of the hominin clade which appear to bridge the gap between genus Australopithecus (see my previous two posts here and here) and our own genus Homo. Of course, with excitement in the world of palaeoanthropology comes controversy. A large part of this controversy centres around whether any of the transitional hominins actually deserve to be included in genus Homo, or whether they all should be placed in the umbrella-like genus Australopithecus (also here).
Meet Australopithecus sediba (sediba means ‘fountain’ in the local seSotho language; Berger et al., 2010) which was present in South Africa between 1.8 and 2.0 millions years ago (Mya).
Many people often view evolution as a smooth and gradual change from one form into another. For humans, that would involve a reduction in facial projection (prognathism), decreasing size of the teeth and increasing brain size.
This week will hopefully demonstrate that these patterns can also be reversed – it’s time to meet the robust australopithecines. they evolved after dental reduction began so had to re-evolve massive teeth, jaws and facial skeleton in general, surpassing any hominin before or since:
The archaic hominins
Time has moved on a bit since last week, both in the real world and in the world of this blog. Now, the archaic hominins are coming in to their own and the date is between 2.4 and 4.5 million years ago.
You’ve been subjected to enough examples over the past few posts of how our anatomy differs from the extant apes, and that these differences allow us to stand upright and walk bipedally. But you deserve better.
This post is all about where and when we see the differences first appear in the hominin fossil record.