From Newsgroup: sci.anthropology.paleo


https://www.pnas.org/doi/epdf/10.1073/pnas.2502158122

Abstract
Light eyes, hair, and skins probably evolved several
times as Homo sapiens dispersedfrom Africa. In areas
with lower UV radiation, light pigmentation alleles
increased in frequency because of their adaptive
advantage and of other contingent factors such as
migration and drift. However, the tempo and mode of
their spread is not known. Phenotypic inference from
ancient DNA is complicated, both because these
traits are polygenic and because of low sequence depth.
We evaluated the effects of the latter by randomly
removing reads in three high-coverage ancient samples,
the Paleolithic UstrCO- Ishim from Russia, the Mesolithic
SF12 from Sweden, and the Neolithic I5077 from current
Croatia. We could thus compare three approaches to
pigmentation inference, concluding that for suboptimal
levels of coverage (<8|u), a probabilistic method
estimating genotype likelihoods leads to the most
robust predictions. We then applied that protocol to
348 ancient genomes from Eurasia, describing how skin,
eye, and haircolor evolved over the past 45,000 y.
The shift toward lighter pigmentations turned out to
be all but linear in time and place, and slower than
expected, with half of the individuals showing dark
or intermediate skin colors well into the Bronze and
Iron ages. We also observed a peak of light eye
pigmentation in Mesolithic times, and an accelerated
change during the spread of Neolithic farmers over
Western Eurasia, although localized processes of gene
flow and admixture, or lack thereof, also played a
significant role.

"By a probabilistic approach, we showed that eye,
hair, and skin color changed substantially through
time in Eurasia. It was reasonable to imagine that
the first hunting-gathering settlers, who came from
warmer climates, had mostly dark pigmentation. We
are now showing that their phenotypes persisted up
to the Iron age. We found the earliest instance of
light skin color in the Swedish Mesolithic, but it
comes from only one sample in >50. Things changed
afterward, but very slowly, so that only in the
Bronze Age did the frequency of light skins equal
that of dark skins in Europe; during much of
prehistory, most Europeans were dark-skinned. A
similar trend, with dark pigmentation long
coexisting with an increasing, yet relatively small
proportion of lighter traits, is observed for hair
and eye color, although there was a temporary peak
of light eye frequency in the Mesolithic period,
when we inferred light pigmentation for 11 out of
35 samples."
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: sci.anthropology.paleo

Primum Sapienti wrote:

Abstract
Light eyes, hair, and skins probably evolved several
times as Homo sapiens dispersedfrom Africa.

That's a conclusion.

Homo sapiens dispersed to Africa, and back out of Africa...

The evidence from chromosome 11 says billions of people
can trace their ancestry to an Eurasian ancestor
significantly older than any Mitochondrial Eve, or even
any Y Chromosome Adam. And the oldest known y chromosome,
A00, was likely a RECENT infusion into modern populations.
It's associated with west Africa, the same place as
"Unknown Ancestor" DNA and even an archaic skull of about
13k years in age.

Disclaimer: Paleo anthropology is about as far away from
a real science as you can get and still be taught in
accredited schools. The archaic skull, though clearly NOT
modern, has been redefined as "Anatomically Modern" by the
politicians pretending to be academics who own paleo
anthropology. Of course, A00 is still there, the "Unknown
Ancestor" DNA still exists and their idiocy just makes it
all harder -- not easier -- to explain away...

In areas
with lower UV radiation, light pigmentation alleles
increased in frequency because of their adaptive
advantage and of other contingent factors such as
migration and drift.

Some humans were sexually selected. Period. We know this
because we can see it even in modern humans who are not
uniformly monogamous, and even where we can't observe
nature we can goddamn well see anatomy. Human testicles
fit between Chimps and Gorillas. Oddly, Gorillas have no
sexual competition and Chimps have oodles of it. Now we
can't be simultaneously both monogamous and promiscuous
so it has to be a case where humans AS A GROUP or a
population practice both, even if individuals don't.

Of course culture plays a big role here, whether or not
certain reproductive strategies (intended or not) are
permissible...

Okay, so AT LEAST some humans are sexually selected, and
this places evolutionary pressures on neonatal traits.
These are traits associated with the young, children, and
supposedly trigger a "Caring" or nurturing response. But,
they are also considered attractive. And these traits
would include things such as hairlessness and, now get
this, light skin...

https://www.wildchimps.org/fileadmin/_processed_/3/3/csm_how-they-grow-up_311d542b0e.jpg

But...

But there's a catch. Light skin in the wrong environment
is sunburn, skin cancer. In another environment, light
skin is vitamin D.

The normal explanation -- because, again, paleo anthropology
is far from a real science -- is INTELLIGENT DESIGN. God or
some aliens decided that some people might benefit from
light skin so they gave light skin to people...

The shift toward lighter pigmentations turned out to
be all but linear in time and place, and slower than
expected, with half of the individuals showing dark
or intermediate skin colors well into the Bronze and
Iron ages.

In Europe, we have plenty of evidence for skin lightening
even since the Black Death. I don't mean that we had the
likes of sub Saharan Africans running the place until the
plague hit but, look at the Welsh. Take Tom Jones for
example. One researcher explained it this way:

If you look at the west coast of Europe, places like
Ireland and Wales are pretty far away from the Mediterranean.
But if you rotate the map 90 degrees counter clockwise,
suddenly your mind sees them as very close together. This
is because we are wired to see movement up & down as more
difficult than left and right.... climbing stairs as
opposed to walking down a hall.

Anyway, long story short: Irish ruins seem to be far more
related to the Basque than to, say, the Vikings...

So, European skin tones appear to have lightened since the
plague. Nobody knows why. One simple explanation I've heard
is that the lighter the skin, the easier to spot a flea if
it landed on you...
--
https://jtem.tumblr.com/tagged/The%20Book%20of%20JTEM/page/5
--- Synchronet 3.21a-Linux NewsLink 1.2