@Jimpithecus, our resident paleoanthropology expert, is working on a follow-up article on how this discovery relates to our understanding of human evolution and the process of science.
What questions do you have about Homo naledi or the current state of human evolution science that Jim could answer in his post?
Not specifically about humans or naledi, but how do they know this:
Meanwhile, back in Africa, we know from genetic evidence that, in addition to H. naledi, another unknown hominin species was present and interbred with our species as recently as 30,000 years ago.
Specifically, what kind of genetic evidence shows interbreeding with another species as opposed to just some subpopulation having some different variation?
There are some very interesting anatomical features, almost a combination of modern lower limbs and much more ancient upper limbs. Is this juxtaposition of “old” and “new” features in a single organism as unusual as it sounds? Also, is there any realistic hope of finding any biomolecules in samples this old?
I’m afraid most of my questions might call for a bit of speculation, but I’ll ask a few anyway, in case @Jimpithecus is willing to play along.
As I understand his blog post on the relationship between humans, Neanderthals, and Denisovans, the Denisovans arose from Homo erectus, who migrated out of Africa about 1.8 million years ago. Meanwhile, Neanderthal (or his predecessor) migrated out of Africa into Europe between 300-500 kya. So far so good?
Based on its mix of “old and new” anatomy, H. naledi is speculated to be an ancient species, perhaps arising as much as 2 million years ago. This would imply that it was an ancestor of H. erectus, and therefore of Denisovans, as well. However, if H. naledi arose after some population of H. erectus already had migrated out of Africa, then H. naledi is an ancestor of Neanderthal and H. sapien, but not of Denisovans and other Asian hominids. Does that logic make sense? How could such a thing be verified? Do the Denisovans show the same type of frontal lobe development as Neanderthal and H. sapiens? How does the H. erectus frontal lobe development compare to H. naledi’s?
Most of this calls for a great deal of speculation, which Dr. Kidder may or may not be comfortable doing. Thanks for the opportunity to ask, though. Hope I’m not too late to the party.