3000 BCE to 5000 BCE most males were killed off by warfare
So there was a "genetic bottleneck" in humanity as metal weapons were produced....during the Bronze Age...
Most of the male population across Asia, Europe and Africa seems to have
died off, leaving behind just one man for every 17 women.
I guess the "New World" was sparred but there was a "genetic bottleneck" in the New World just due to the Bering Strait migration that caused a split into two small groups - one going to South America...
"Our belief used to be that the center of humans leaving Africa was in
East Africa. This paper focuses attention on southern Africa, and in
particular to a group of hunter-gatherers, the Bushmen, who speak one of
the Khoisan languages," said Feldman. These languages are characterized
by the presence of "click" sounds.
https://news.stanford.edu/news/2011/march/feldman-africa-genetics-030411.html
Contrary to the claim of GEE McPherSon - the "cognitive revolution" was well-before 30,000 years ago....
So GEE McFearSun is claiming the Mt. Toba supervolcano created the loss of the stratospheric ozone
the loss of stratospheric ozone...that occurred also in the past about 74000 years ago when the Toba supervolcano went off...
GEE McFearSun... But they cite just one paper that is just an analysis without the archaeological evidence while there is conflicting evidence stating otherwise:
Supervolcano Not to Blame for Humanity's Near-Extinction
GEE McFearSun quote: starting around 15 minutes:
Some thousands of years ago, several thousands of years ago, so maybe when we started growing brains at scale is when we made the fundamental mistake and went into human population overshoot. Or maybe it's worse than that. Maybe it was during the cognitive revolution, more than 30,000 years ago when humans, for reasons that are still not explained, humans became the first species that were able to imagine things that they did not personally experience - even without being able to taste and smell and see things: Humans were able to imagine things. And one of the consequences of that cognitive revolution was humans viewed themselves as superior to other organisms; superior to other - up until the cognitive revolution that didn't happen. We viewed ourselves as just another in a vast array of species. But during the cognitive revolution, we somehow came up with the idea that we are SUPERIOR to all the other species on Earth and what that did was gave us the right to kill and eat other species.. it gave us the right, in our minds, to torture other organisms... And you know that was at least 30,000 years ago....
This is one of the reasons that I have been promulgating the message that only love remains for such a very long time: No shame and no blame...somebody who lived more than 30,000 years ago? That doesn't make any sense.
Actually I just documented from the "Radical Anthropology" scholars that our original human culture - the Baka culture - did intentionally not overkill animals - and had a peaceful culture without war, with spiritual healing as the foundation....
So no the "cognitive revolution" was NOT the cause of the tipping point....
The "cognitive revolution" was way before 30,000 years ago - more like 100,000 years ago in the Baka-San Bushmen culture....
Apart from the click-speaking hunter-gatherer populations from South
Africa and Tanzania, they also studied Pygmies and 21 agriculturalist
populations. Statistical analysis showed that the Bushmen had the
greatest genetic variation and are most likely to be the source
population from which all other African populations diverged.
https://www.nature.com/articles/d41586-018-07164-9 (2018 study)
These preliminary results suggest that more than 40,000 years ago, two
of the groups — the San and the Baka Pygmy — were roughly twice the size
of other ethnic groups present at the time, and that the San and Baka
overlapped in central-eastern or southern Africa. Researchers presented
these as-yet unpublished results at an American Society of Human
Genetics (ASHG) meeting in San Diego, California, last week.
No I'm not going to "shame and blame someone who lived more than 30,000 years ago" as GEE McFEarSun claims because the San Bushmen-Baka Pygmy culture is based on protecting ecology!!
Statistical models of the data indicate that the Hadza and the
Sandawe people of Tanzania shared an ancestor in the past 30,000 years.
The
findings also suggest that there was intermingling during that period
between the Hadza, the San in southern Africa and the Baka in central
Africa, all of whom were traditionally hunter-gatherers. “I think we are
seeing an ancient common ancestry between the major hunter-gatherer
groups in Africa,” Tishkoff says.
Some of the findings align with
signals of mixed Hadza and San ancestry in DNA extracted from 2,500- to
8,100-year-old human remains1,
says Pontus Skoglund, a palaeogeneticist at the Francis Crick Institute
in London. “I had been thinking about an interconnected hunter-gatherer
population stretching from present-day Tanzania to South Africa.”
fascinating.
2020 study:
all Khoe-San groups display genetic diversity approaching the levels in
other African groups and a reduction in effective population size
starting around 100,000 years ago. Hence, all human groups show a
reduction in effective population size commencing around the time of the
Out-of-Africa migrations, which coincides with changes in the
paleoclimate records, changes that potentially impacted all humans at
the time.
OK....
we found the mean divergence time of all Khoe-San populations from all other groups to be within the 200–300 ka range
The Mbuti then diverged around ∼220 ka, SD 10 ka (TT method: 215 ka, SD 9
ka), with the other population divergences occurring subsequently.
WOW THE BAKA diverged from the Khoe-San around 220 ka?? amazing.


https://research.vu.nl/ws/portalfiles/portal/118482841/A_two_million_year_long_hydroclimatic_context_for_hominin_evolution_in_southeastern_Africa.pdf


OK so I previously blogged on this:
https://elixirfield.blogspot.com/2021/08/the-earliest-anthropogenic-landscape-in.html
However, ca. 85 ka, during a wet period following the
last prolonged arid period, the long-term relationship between climate
and vegetation was decoupled. Lake levels remained high for the last
85 kyr but species richness never recovered, and instead remained at
low values previously associated with the driest intervals of the last
600 kyr.
Unlike their Middle Pleistocene counterparts, however,
these humans used burning to halt the typical cycle of forest
recolonization by producing large quantities of ignitions that were
outside the normal seasonality of lightning strikes.
However, there is evidence that at some point near the Middle-Late
Pleistocene boundary humans under-went a threshold-crossing shift in
their behavior that is detectably
different from what came before. The sustained, transformative
effects of these behaviors on sculpting ecosystem functions extend
deep into the human past and the evolution of these systems are
inextricably bound to the evolution of our species itself.
So the question is - do we know if the San Bushmen still use fire to change their landscape?
The use of fire in group hunting is more common in the
grassland savannah areas. Members of the group are positioned
strategically around a patch of grassland known to contain wild
animals. The area is then set on fire and animals are killed with
cutlasses and clubs as they run out of the area to escape the
fire.
https://www.fao.org/3/W7540E/w7540e0i.htm
The thing is that I have NEVER seen that method of hunting described being used by the San Bushmen!!!
Afolayan, 1980;
Martin. 1983
Those are the references. I think I read that Martin book already for a University class! It's just a general overview book. Calvin Martin I think.
Keepers of the Game: Indian-Animal Relationships and the Fur Trade, Calvin Martin, 23 Nat. Resources J. 281 (1983).
Yeah - wouldn't expect that to be a good source of the Kalahari!!
So the other one?
https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2028.1980.tb00272.x
The influence of seasonality on the distribution of large mammals in the Yankari Game Reserve, Nigeria
Yeah that's NOT going to be on the San Bushmen either.... Oops.
By converting the natural seasonal rhythm of wildfire into something
more controlled, people can encourage specific areas of vegetation to
grow at different stages. This so-called “pyrodiversity”
establishes miniature habitat patches and diversifies opportunities for
foraging, kind of like increasing product selection at a supermarket.
https://www.pbs.org/newshour/science/early-humans-used-fire-to-permanently-change-the-landscape
The discovery of fire by humans: a long and convoluted process


That's on Australia....

yeah I don't know - scant evidence to be sure!
F. Scherjon, C. Bakels, K. MacDonald, W. Roebroeks, Burning the land: An
ethnographic study of off-site fire use by current and historically
documented foragers and implications for the interpretation of past fire
practices in the landscape. Curr. Anthropol. 56, 299–326 (2015).
Herders in AFrica - but STILL no San Bushmen evidence!!