Discussions on the history and historiography of Australia's New England

Sunday, April 28, 2019

The spreading Denisovans

This short piece by  Meilan Solly, in the Smithsonian ,The Hominins We’ve Been Calling Denisovans Are More Diverse Than Previously Thought, provides a very useful summary of current thinking.

So far the only Denisovan remains that have been found are from a cave in Siberia. But the DNA analysis suggests that their influence was wise spread, with several Denisovan groups.

The significance for New England history and the history of the Australian Aborigines in general is that while we now know that Aboriginal ancestors interacted with the Denisovans we do not know when and where. Had the Denisovans actually reached Sahul, prehistoric Australia, or was the interaction earlier. The second is the current view, in South East Asia.

The further back the dates of human occupation of Sahul are pushed, the more complex the story becomes. At 62,000 years, all things are (I guess) on the table.

8 comments:

Johnb said...

Those Asian Aboriginal populations having a Denisovan contribution in their gene pool Jim have so far been found where their settlement required significant navigation. Luzon in the Philippines has never, in recent geological times been connected to a continuous land mass.
In Indonesia a Denisovan connection is East of the Wallace Line which leads us to Papua/New Guinea and Oz.
https://eurekalert.org/pub_releases/2019-04/mpif-mda041119.php
The new evidence also unexpectedly shows extra mixing between Papuans and one of the two Denisovan groups, suggesting that this group actually lived in New Guinea or its adjacent islands. Moreover, Denisovans may have lived in the area until as recently as 30,000 years ago, making them one of the last surviving groups of archaic hominins. "People used to think that Denisovans lived on the Asian mainland and far to the north," says Cox. "Our work instead shows that the center of archaic diversity was not in Europe or the frozen north, but instead in tropical Asia." Stoneking adds, "Moreover, this archaic diversity seems to have persisted much longer in Island Southeast Asia and New Guinea than elsewhere in the world."

Jim Belshaw said...

That's fascinating, John. An earlier DNA study showed Denisovan influence in both Aborigines and Papuans but linked that to an earlier near SEA contact. This was before the split between Papuans and Aborigines. I don't know what to think!

Johnb said...

Homo erectus and evolution over 1.3+ million years Jim is my best intuition. Another less likely prospect is that the the science has proven misleading, if so then time will resolve that.

Jim Belshaw said...

Your comment on the science is important, John. Models are just that, models. We rely on later work tocorrect.

Johnb said...

Chris Stringer has an omnibus review paper of where the latest human evolutionary Science has reached Jim but it is behind a pay wall.
This review of a skull from Southern China neatly illustrates the growing complexities in the understanding of anatomically modern humans..
“The Hualongdong fossils are also by no means the oldest hominin remains found in East Asia; multiple specimens of Homo erectus and related lineages have been unearthed going back more than 1.6 million years. A 2018 study of more than 100 tools from Shangchen suggested that archaic hominins were in China 2.1 million years ago, though no hominin fossils of that age have turned up (yet).”

http://blogs.discovermagazine.com/deadthings/2019/05/01/hualongdong-skull/#.XM6Z3oqubmp

Jim Belshaw said...

Thanks, John. I will bring this up in a post!

Johnb said...

I suspect that as time passes Jim it will be realised that Africa was not unique, just the first and most studied as a consequence of history and circumstance. I read another genetic paper yesterday looking at continent wide African dna that established as one of its findings that North Africans were more closely Eurasian related les so to the Sub Saharan African gene pool. My immediate thought referenced the 300kyrs old HS fossils found in Morocco.

https://genomebiology.biomedcentral.com/articles/10.1186/s13059-019-1684-5

Jim Belshaw said...

Thanks for this link, John. I have brought it up on twitter and my public FB page. This is what i wrote:

"Whole-genome sequence analysis of a Pan African set of samples reveals archaic gene flow from an extinct basal population of modern humans into sub-Saharan populations" is a bit of a mouthful.

DNA analysis can be eye-glazing stuff for. A key conclusion of this African analysis and others including Ancestry is that we are all mongrels with multiple genetic admixtures. We also carry varying traces of other hominid ancestries. People slept around.

The DNA analysis helps show us how groups moved across the continents in large scale migrations both displacing and mixing with earlier groups. Slowly we are writing a hominid history of which our written history is but a tiny part. The link to the paper follows."

I agree with your assessment.