At https://phys.org/print449151180.html … as the argument on what constitutes a modern human heats up and the date to be assigned to their migration Out of Africa we now have another spanner in the works (or sort of as these are old humans with modern human embellishments. The old idea modern humans evolved around 50,000 years ago, mainly because around 40,000 years Neanderthals were superceded by modern human physical types in Europe, has been dealt a blow as anatomically modern human skulls have been unearthed in Ethiopia and Morocco that go back to nigh on 300,000 years ago (and in the Levant to over 100,000 years ago). Rather than just re-designate the Neanderthals as modern humans, the most logical solution, the idea is being floated that Europe was some kind of modern human desert. There is still heavy resistance against looking at Neanderthals as the equals of modern humans – even though a lot of recent evidence might challenge that view. For instance, a few weeks ago a new study reckoned they hunted animals in packs, spearing them at close quarters (the sort of thing occurring in Africa until recently, amongst the bushmen for example).
A new study in the Journal of Human Evolution (June 2018) has shown the cranium of an extinct Australopithecus hominin found in a cave in South Africa has similarities to the inside of skulls of modern humans, going back a couple of million years ago. Using high resolution scanning the researchers explored the inner structure of the skull. What they are talking about is not the shape of the skull, as such, the old way of distinguishing human physical types, but the composition of the skull inside the bone case – a layer of spongy bone tissue designed to protect the brains. Defining what is and what isn't a modern human may have to be revised – but this may open a can of worms. We may expect the lid to be firmly kept on.