A paper (Reconstructing Denisovan Anatomy Using DNA Methylation Maps, by David Gokhman et al., Cell, Vol 179 - 1, P 180-192. doi:https://doi.org/10.1016/j.cell.2019.08.035) published today came up with a "reconstructed Denisovan anatomical profile".
Unlike forensic reconstructions (there aren't enough Densiovan bones to do such a thing), the authors used DNA hypermethylation to work out how genes were regulated and validated against Neanderthals and chimpanzees.
They found that "Denisovans likely shared with Neanderthals traits such as an elongated face and a wide pelvis", and also Denisovan traits such as "as an increased dental arch and lateral cranial expansion".
But how did they do this? They looked for differences in the activity of certain genes known to be linked to anatomical features.
They found 32 different traits which give a good idea of what the Denisovan skeleton looked like.
They have several common features with Neanderthals such as The 21 shared traits include characteristic Neanderthal features such as "robust jaws, low cranium, increased cranial base growth, low forehead, thick enamel, wide pelvis, large femoral articulations, wide fingertips, and large ribcage"
Their face was wider than that of modern humans and Neanderthals and it protruded more than ours but less than the Neanderthals' face.
Face shape was also predicted: "we predict a widening of the Neanderthal and Denisovan chin compared to MHs [modern humans]. We also predict that the Denisovan had a more triangular face compared to the Neanderthal".
To validate this method they used it to define the morphology of chimps and Neanderthals and obtained a precision of +85% in predicting their traits (here of course they had bones to compare to their predictions, validating them).
The images below reproduce the work of Maayan Harel who also illustrated the paper:
Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2019 by Austin Whittall ©
Amazing post!!...and I think, so amazing is all the data that researchers have been extracting from the remains of Denisova 3 individual (only a tiny bone and a few teeth, but from which valid DNA could be obtained). But this reconstruction filled my astonishment.
ReplyDeleteActually, the paper is extremely interesting, though it´s too complex to my knowledge. Anyway, it seems clear to me what the authors are suggesting … as long as certain requirements are met, this method for predicting changes of traits, relative to other species, could be, at least, reasonably accurate…
So, the face shown probably is representing fairly more than a mere tentative reconstruction of a generic Denisovan one…
Not less interesting to me, are the appreciations made by the authors, in the sense that many of the Denisovan reconstructed traits, could be correlated with “Neanderthal like” fossils from the Middle Peistocene of China, particularly Xuchang man (dated between 130-100 Ka), which is one of these “hard to classify” East Asian hominids (as well as Maba man, dated >130Ka and Xujiayao man, dated 240 Ka average age, are)…all of them with Neanderthal similarities, but still retaining (apparently upon the opinion of non Chinese anthropologists, too) at least some traits that resemble that´s from Zhoukoudian H. erectus individuals, dated at 780 Ka…
These fossils probably have hidden clues, not only about Denisova lineage, but also others related to the way in which genus Homo could have evolved in Middle Pleistocene times…though, unfortunately, many of these clues will never be decoded, mainly due to their lack of DNA.
As it is known, obtaining valid DNA requires an exceptionally well preserved material, which is a very restrictive condition for old archaeological contexts (>40 ka). There is not a well defined age as a limit, as it depends on the burial environment history…but one can tentatively suppose that it would be extremely rare that a 150Ka or older bone/teeth could qualify for this
Anyway, it becomes clear that DNA researches have an ever growing importance as tools, able to provide a different, but not less valuable approach, in order to explore into human origins...In fact, while the lack of DNA evidence in the above mentioned fossils, only leaves room for speculations about them (although, very interesting ones…)… its presence in Denisova Cave remains, have led to the most relevant researches, being this reconstruction an impressive example of this.
Best regards
Marcelo