[Rockhounds] Hominids nearly went extinct 900,000 years ago

[Tim Fisher]

Google the Mitochondrial Eve theory, which has since been thoroughly
disproven. It's actually kind of an entertaining read, the first time I came
across it on a genetic genealogy website I said WHAT THE F to myself 😊

Tim Fisher
nospam at orerockon.com



-----Original Message-----
From: Rockhounds <rockhounds-bounces at rockhounds.drizzle.com> On Behalf Of
Dora Smith
Sent: Saturday, September 2, 2023 6:23 AM
To: Rockhound List <rockhounds at rockhounds.drizzle.com>
Subject: Re: [Rockhounds] Hominids nearly went extinct 900,000 years ago


Thanks for the link to the preprint.  

What occurs to me is that there is a known genetic bottleneck where humans
were reduced to 5000 or so breeding pairs about 65,000 years ago,
corresponding to the Toba supereruption - which was larger than
Yellowstone's notorious supereruptions.   It is not clear if this is the
same genetic bottleneck or a different one, nor how they established the
time frame.

It also isn't clear what the actual consequence was.    A million years
ago, human species were still sorting themselves out.  Rapid climate
changes, which could cause specific places to go from wet to dry and warm to
cold and back again often and quickly, forced hominids to become more
adaptive and pushed human intelligence.   It has been thought ofr a long
time that this drove human evolution.   It would have caused other hominid
species to go extinct, and could not have done its evolutionary work if it
had not also stressed our own ancestral population.    We must also keep in
mind the mounting evidence that modern humans are as much the product of
interbreeding among the hominid lineages as direct line evolution and
competition between teh lineages.   

So in short I'm not sure what this tells us that we didn't already know.
It also isn't clear they know what genetic bottleneck and in what time frame
they are talking about.

Yours,
Dora Smith







 On Friday, September 1, 2023 at 01:05:26 PM CDT, Paul <etchplain at att.net>
wrote:





 Human ancestors nearly went extinct 900,000 years ago A new technique
analysing modern genetic data suggests that pre-humans survived in a group
of only 1,280 individuals.
Anna Ikarashi, Nature News, August 31, 2023
https://www.nature.com/articles/d41586-023-02712-4

Humanity’s Ancestors Nearly Died Out, Genetic Study Suggests The population
crashed following climate change about 930,000 years ago, scientists
concluded. Other experts aren’t convinced by the analysis. Carl Zimmer, New
York Times, August 31, 2023
https://www.nytimes.com/2023/08/31/science/human-survival-bottleneck.html

The PDF of the preprint of the paper is at:

Hu, W., Hao, Z., Du, P., Di Vincenzo, F., Manzi, G., Pan, Y.H. and Li, H.,
2021. Genomic inference of a human super bottleneck in Mid-Pleistocene
transition. bioRxiv, pp.2021-05.
https://www.biorxiv.org/content/10.1101/2021.05.16.444351v3.abstract

The paywalled paper is at:

Hu, W., Hao, Z., Du, P., Di Vincenzo, F., Manzi, G., Pan, Y.H. and Li, H.,
2021. Genomic inference of a human super bottleneck in Mid-Pleistocene
transition.
Science, 381(6661), pp. 979-984.
https://www.science.org/doi/10.1126/science.abq7487

Yours,

Paul H.
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