
Fossils from Morocco complicate the story of modern humans - biridir
https://www.nature.com/scientificamerican/journal/v317/n3/full/scientificamerican0917-12.html
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tombh
Coincidently I've been reading and youtubing about human evolution recently.
If anyone's interested here are some bullet point facts that may surprise
other laymen.

* In the last few years the Out Of Africa theory (modern humans originated solely in Africa) has received stiff competition from the Multi Regional theory. Namely that waves of human species have left Africa since we diverged from chimpanzees 4 million years ago and that our ancestors are from all the homo-inhabited regions of the world to a greater or lesser extent.

* Neanderthals and Denisovans are 2 known species that certainly inhabited much of the world (apart from the Americas) from around 2/300,000 to 50,000 years ago.

* We certainly bred with Neanderthals and Denisovans, some of us contain up to 4% of their DNA.

* Mammals generally take about 5 million years before they evolve far enough to be reproductively isolated. Of course before then there can still be breeding problems, for which there is evidence of in our breeding with the aforementioned.

* DNA from human skeletons several hunreds of thousands of years old can still be analysed.

* Mitochondrial DNA is passed by mothers only and so undergoes very little mutation. So it provides a stable and valuable signature for detecting ancient affinities between species/sub-species.

* By analysing the variation within genes certain characteristics can be interpreted like population size (eg; there were very few Denisovans) and that there are as yet unidentified species that humans have inherited from.

* Neanderthals possessed the FOXP2 gene known to be central in human speech.

* One of the oldest known oral traditions has evidence to verify a story from around 30,000 years ago: that Australian aboriginees brought the palm tree seeds with them from the north. See: [http://www.abc.net.au/news/2015-04-03/aboriginal-legend-palm...](http://www.abc.net.au/news/2015-04-03/aboriginal-legend-palm-tree-origin-central-australia-research/6369832)

Forgive any errors in this amateur homework report.

~~~
detritus
Wow. That last bullet point is particularly remarkable to me - both the
implied level of 'technological understanding' and presumed foreplanning for
significant journeys 30K years back and for the capacity of oral history to
record what come today might not be the most pertinent information.

Also quite amusing in the context of contemporary Australia's philosophy where
alien plants and animals are concerned! :)

~~~
yuchi
Citing that article:

> “It suggests that Aboriginal oral traditions may have endured for up to
> 30,000 years, and lends further weight to the idea that some Aboriginal
> myths pertaining to gigantic animals may be authentic records of extinct
> megafauna”

Wow ^ 2

~~~
pamqzl
I'm always _extremely_ skeptical when someone suggests that oral traditions
could possibly have survived for long periods of time. That's twelve hundred
generations! Given what we know about the speed at which Chinese Whispers tend
to drift, the idea that any story can last 1200 generations is an
extraordinary claim that demands extraordinary proof.

Hundreds of Aboriginal tribes had hundreds of contradictory myths on hundreds
of subjects. Most of them are verifiably false (e.g. those rocks over there
are not, in fact, the remains of three young women who got turned into stone
for disobeying their father). Some of them are probably correct by complete
accident.

As for gigantic animals... well, they're a pretty common motif in myths and
stories all around the world. Maybe it's some distant memory our cultures all
have of the larger animals that used to live around here... or maybe it's just
because giant animals are cool. In Aboriginal myths, giant animals are often
_really really_ giant, because they're used as explanations for geographic
features -- e.g. rivers are caused by the meanderings of a giant snake.

~~~
micheljones
Some tribes in north of Australia have verifiable myths about the geography of
the lands that have been under the sea off the north of Australia for 6-8
thousand years at least (meaning, the description of the land features matches
the sea floor geography).

~~~
flukus
Has anyone quantified their myths properly? If not then they're just cherry
picking.

~~~
micheljones
Do you have any proof that they are just cherry picking?

~~~
flukus
No, I just assume they are until they provide data to prove otherwise. We
don't even know if the same tribes were in the same area that long ago.

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meri_dian
The San people of southern Africa are claimed to be the living human group
with the most ancient divergence from the rest of humanity, around 200,000
years ago. That they are so similar to the rest of humanity has always made me
wonder if the commonly accepted divergence date ranges should be pushed back.

From the Wiki:

"A DNA study of fully sequenced genomes, published in September 2016, showed
that the ancestors of today's San hunter-gatherers began to diverge from other
human populations in Africa about 200,000 years ago and were fully isolated by
100,000 years ago, well before the first archaeological evidence of modern
behaviour in humans."

[https://en.wikipedia.org/wiki/San_people?wprov=sfla1](https://en.wikipedia.org/wiki/San_people?wprov=sfla1)

~~~
Danihan
Do you know if they are related to the Berbers?

~~~
micheljones
Well, we are all related to each other, the only question is how _closely_
related we are. And as for that, any non-Khoisan/non-Pygmy human subgroup is
more closely related to any other non-Khoisan/non-Pygmy subgroup than they are
to Khoisan or Pygmy people. In other words, Khoisan and Pygmyies are the most
distant cousins to all other homo sapiens (diverged from us 175-200 thousand
years ago).

------
micheljones
I was always surprised by the tendency of anthropologists to assign hard
evolutionary 'milepoints' based on the very limited set of archeological data.
Most egregious example is 'behavioral modernity' theory which claims that homo
sapiens developed language, culture and art only relatively recently (30kya)
because that's how old the currently oldest archeological finds of culture/art
expression are. This doesn't stand up even to the simplest application of
Occam's razor.

~~~
ralfd
But then the question is why our ancestors didn't invent stuff 100 thousand
years earlier.

~~~
micheljones
Well, that's not what I'm arguing. What I am arguing is that lack of proof is
not proof of lack - the fact that, for example, currently oldest artwork we
know of is 30 000 years old does not prove that's when homo sapiens started
making art and not any earlier, but instead that it proves that humans have
been making art AT LEAST 30kya, AND that they must have started doing it
earlier.

P.S. the 'oldest art is 30 thousand years old' bit is in the context of
'behavioral modernity' theory at the time it was posited, based on European
cave art; in the meantime, we've found even older art in a cave in Indonesia
(40 thousand years old).

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eponeponepon
I've never really grasped where the surprise comes from with these kinds of
discoveries - we know that our ancestry always had the potential to give rise
to lines that look very much like us, since _we_ look very much like us. Why
should it be a surprise if it happened more than once? We're looking at a
terribly long timescale, after all - at least by comparison to our recorded
history.

~~~
gus_massa
Evolution is not linear. At each step there are multiple choices. If you split
a population, each one will have different problems in it's environment to
solve or they may "find" different solutions to the same problems.

After some time the changes in the ADN make the two population incompatible
for reproduction, so they become different species. [An easy case is when the
number of chromosomes changes in one of the part but it doesn't change in the
others. But more subtle changes are more frequent.]

~~~
danans
> After some time the changes in the ADN make the two population incompatible
> for reproduction, so they become different species.

The time scales being discussed here are orders of magnitude too short to even
consider speciation, evidenced by what we know about our human/Neanderthal
hybrid ancestors, and the fact that a Pygmy or Khoi-San person can have viable
offspring with any person of the opposite gender in the human diaspora today.

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eXpl0it3r
I'm surprised how much variations there are in the dating of the fossils. At
first it's 40'000 years, then 160'000, then between 280'000 and 350'000.

Can someone explain to me why there's so much difference?

~~~
tinix
Carbon dating is a flawed concept.

~~~
Strilanc
They're obviously not using carbon dating. The ages are too big.

IIRC The half life of carbon 14 is too short to distinguish samples that have
been decaying for 50k years from background noise. You have to use other kinds
of radiometric dating instead.

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andrewflnr
I wish they'd go into more detail about how the shape of the brain case
affects brain organization. Does anyone have a good layman-oriented source on
that?

Edit: it looks like both are affected by differences in brain development.
[https://www.mpg.de/623578/pressRelease201011021](https://www.mpg.de/623578/pressRelease201011021)

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halflings
It doesn't seem like there's anything new in this article compared to the
original announcement.

