
Modern human brain organization emerged only recently - wslh
https://www.sciencedaily.com/releases/2018/01/180125105444.htm
======
sunstone
How do they reconcile the fact that apparently only brains after 35k years ago
show this new brain morphology when humans left Africa at least 70k years ago
(when they showed up in Australia).

So one of the groups, either the "in Africa group" or the "out of Africa"
group still should have the "old style brains" unless magically the changed
happened in both groups at simultaneously. And yet I believe all humans
currently alive have essentially similar brains.

~~~
astebbin
It's uncomfortable to consider, but there is strong evidence to suggest that
the brains of Australian aboriginal people differ in significant ways from
their Caucasian bretheren. One study found the aboriginal visual cortex to be
significantly larger than the Caucasian equivalent [0], possibly as an
adaption to Australia's (visually) vast open spaces. The same study found the
Caucasians had significantly larger parietal lobes and cerebellums - the same
structures mentioned in this article. Another study found that Caucasians have
significantly larger brains on average compared to those of aboriginals [1].

There's also evidence to suggest that modern humans from India [2] have
contributed to the Australian gene pool for millennia (long before the arrival
of the British), so more dramatic cranial differences may have already been
averaged out.

EDIT: deleted figure mis-remembered from an unrelated study.

[0]
[https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1261675/](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1261675/)
[1]
[https://www.ncbi.nlm.nih.gov/pubmed/6926391](https://www.ncbi.nlm.nih.gov/pubmed/6926391)
[2]
[http://www.pnas.org/content/110/5/1803](http://www.pnas.org/content/110/5/1803)

~~~
kakarot
We better get this racism thing in check before we're literally dealing with
different species of human (assuming that some groups of people remain
isolated and we don't experience total global homogeneity in the future)

~~~
tomrod
I thought racism was defined as:

> prejudice, discrimination, or antagonism directed against someone of a
> different race based on the belief that one's own race is superior.

I completely agree that when looking at differences among population groups in
a species, one should avoid normative statements such as "such and such makes
this population superior," but is there harm caused by identifying differences
in averages, medians, and variance in said defined population groups? In other
words, if I am speaking about dogs, is it inappropriate to say chihuahuas are
on average smaller than boxers and labs? Same species, but distinct
populations.

I think that is at the heart of it. To be "colorblind" to both the historical
and modern claims of specific population superiority in one dimension or
another is misguided-bad claims made in good faith should be addressed head
on, in requests for citations, evidence, etc. Similarly, to identify where
differences may occur seems to be a reasonable action so long as there is
recognition to cultural or historical drivers too, as GP implicitly identifies
with the optical adaptation mentioned (though, TBH, I have not read the study
he or she proffers and thus have no insight to the claim).

~~~
kakarot
On one hand, we have Darwin, who straight up wrote a book about why some races
are superior [0], and on the other hand we have extremists who take offense
even at assessments like "Men are on average stronger than women."

For a modern-day Darwin, we have James Watson, the father of genetics, who has
some interesting things to say [1]

[0]
[https://en.wikipedia.org/wiki/On_the_Origin_of_Species](https://en.wikipedia.org/wiki/On_the_Origin_of_Species)
[1]
[https://en.wikipedia.org/wiki/James_Watson#Controversial_com...](https://en.wikipedia.org/wiki/James_Watson#Controversial_comments)

James Watson definitely has a masculine, biased perspective, but I mostly
consider him to be somewhere in the middle of the spectrum. Yet, his career
has suffered greatly for his remarks dealing with race and genetics.

Personally, I think it is patronizing if not downright deceitful to pretend
differences don't exist between isolated demographics, but it will remain a
touchy subject for a long time and most scientists will see what happened to
Watson and pursue other areas of research.

~~~
wycs
It is something we will have to grapple with. Cognitive genomics is already
starting to confirm very politically incorrect things, such as the the
confirmation of a dysgenic trend in Iceland, which has been implied from
phenotypic data but career ending to acknowledge:
[https://www.gwern.net/docs/genetics/selection/2017-kong.pdf](https://www.gwern.net/docs/genetics/selection/2017-kong.pdf)

This is the tip of the iceberg. Once we have a million genomes tagged with
cognitive measures, a huge swath of politically-incorrect but factually true
descriptive statements will be confirmed. We need to work now to avoid
confusing the descriptive with the normative and be willing to consider
technological fixes for unfair distributions of economically valuable allies,
such as embryo selection and direct genetic modification. Our society is so in
denial of biological realities, this may not happen in time. But there will be
competitive pressure from Asian (and perhaps Islamic) societies that do not
share our tabbos.

~~~
kakarot
> willing to consider technological fixes for unfair distributions of
> economically valuable allies, such as embryo selection and direct genetic
> modification

A short story about the consequences of normalized post-birth genetic
alteration:
[http://compellingsciencefiction.com/stories/thelittlegods.ht...](http://compellingsciencefiction.com/stories/thelittlegods.html)

A short description of the pre-birth and post-birth conditioning present in
Aldous Huxley's famous _Brave New World_ :
[https://en.wikipedia.org/wiki/Brave_New_World#Fordism_and_so...](https://en.wikipedia.org/wiki/Brave_New_World#Fordism_and_society)

 _The Last Book In The Universe_ takes a different approach to the issue. A
cataclysmic event called The Big Shake destroys society, and only a small
group of surviving scientists hidden underground were able to genetically
modify their offspring to be superior to the rest of the world. This creates
an immensely divisive class system, and the genetically altered humans live
and govern separately from the rest of the planet.

This will not be an easy problem to solve, and there is no telling what the
future effects will be. But it seems precise genetic alteration is the
inevitable holy grail, doesn't it?

------
perl4ever
As a layperson, I find this article deficient of worthwhile information,
because while it juxtaposes two examples of skulls which are clearly
different, it says nothing about the variance in modern human brain shape. It
doesn't seem interesting to me unless one were to characterize the variance
and describe the ancient skull in terms of the modern distribution.

------
cafebeen
Note, the original paper is about evolutionary patterns of overall brain
shape, which is far from indicating how brain organization evolved. The
important parts of brain organization are encoded by patterns of structural
and functional connectivity, which are internal to the brain and not well
depicted by the overall shape. The paper is great, but the write-up just jumps
to some distant conclusions.

~~~
Gibbon1
I'm reminded of head binding practices at this point.

~~~
stochastic_monk
I’m reminded of phrenology.

------
wozer
Original article:
[http://advances.sciencemag.org/content/4/1/eaao5961.full](http://advances.sciencemag.org/content/4/1/eaao5961.full)

------
nrau
What's interesting that if the basic point is true (that modern human brains
emerged only 100,000 - 35,000 years ago) then its amazing (and scary) how
quickly things have moved from there. It wasn't that long after "relatively
speaking" that the Greeks emerged, then the Romans, Egyptians, Europe, Asia,
etc, and now our modern technology driven civilization.

~~~
danieltillett
Speed of evolutionary change is basically proportional to the population size.
Thanks to the huge increase in population size after the rise of agriculture,
more human evolution has happened in the last 5000 years than the previous
500,000.

~~~
TheAdamAndChe
Really? I thought selective pressure was required to cause a major shift in
the average human. The reason that our population has boomed is because our
selective pressure has declined significantly. Or are you more talking about
the adaptability of the species overall has increased?

~~~
danieltillett
Evolution acts on genetic diversity present in the population. The rate at
which new genes (mutations) appear is basically a constant proportional to the
population size (i.e. double the population and you double the rate new genes
are formed). The rate at which new genes under positive selection spread
through the population is approximantly equal to the log of the population
size. This means it only taken 3x longer for a new gene to spread through a
population of 100 million as it does to spread through a population of 1
million.

The end result is the bigger the population the more evolution even if in a
static environment most of the evolution is invisible. Of course the
environment of farmers is very different to hunter-gathers so there has been a
large amount of visible evolution in the last 5000 years.

------
randomdrake
Study: The evolution of modern human brain shape

Citation: Simon Neubauer, Jean-Jacques Hublin, Philipp Gunz. Science Advances,
2018; 4 (1): eaao5961.

Link:
[https://doi.org/10.1126/sciadv.aao5961](https://doi.org/10.1126/sciadv.aao5961)

DOI: 10.1126/sciadv.aao5961

Abstract: Modern humans have large and globular brains that distinguish them
from their extinct Homo relatives. The characteristic globularity develops
during a prenatal and early postnatal period of rapid brain growth critical
for neural wiring and cognitive development. However, it remains unknown when
and how brain globularity evolved and how it relates to evolutionary brain
size increase. On the basis of computed tomographic scans and geometric
morphometric analyses, we analyzed endocranial casts of Homo sapiens fossils
(N = 20) from different time periods. Our data show that, 300,000 years ago,
brain size in early H. sapiens already fell within the range of present-day
humans. Brain shape, however, evolved gradually within the H. sapiens lineage,
reaching present-day human variation between about 100,000 and 35,000 years
ago. This process started only after other key features of craniofacial
morphology appeared modern and paralleled the emergence of behavioral
modernity as seen from the archeological record. Our findings are consistent
with important genetic changes affecting early brain development within the H.
sapiens lineage since the origin of the species and before the transition to
the Later Stone Age and the Upper Paleolithic that mark full behavioral
modernity.

------
leonroy
It's interesting to note that a technological civilization has occurred only
in the past 200 years. Homo sapiens have been around on the planet for a long
time so why is it only happening now?

I suspect that easy access to large amounts of food, more time available for
mental activities and the easy spread of information have given us advantages
our ancestors did not have despite the apparent similarities in our brains.

One tragedy currently ongoing is that many potentially brilliant minds in
LEDCs are suffering from lack of the above three items. It does beg the
question - how much mental capability could humanity gain by ensuring everyone
on the planet has food, time and access to knowledge.

~~~
dalbasal
Depends what you consider technology, I would say.

Plant and animal domestication. A heavy hand axe that gave homo erectus a more
dangerous clank than a big ram? Fish traps? Hydraulic engineering?

Yuval Noah Harari puts the start around the same time as this article's modern
brain, the palaeolithic revolution. The point at which cultural evolution
takes over and replaces biological evolution as the driving force of change.

But yeah, we have a ton of wasted potential. Nutrition, education, information
and (uncomfortably) inbreeding along with the many types of unavailable
opportunities...

------
cm2187
What is striking is the contrast between how little we understand how the
brain actually works, and the bold statements about no difference between men
and women brains, everything is nurture/nothing nature, etc. The reality is
that we don’t really know. I am dying for science to figure out, but until
then I only take claims arguing either way as made up opinions.

~~~
Karnickel
> the bold statements about no difference between men and women brains,
> everything is nurture/nothing nature, etc.

You are attacking a position that is not the common scientist position at all.
Your whole comment is a bit surprising given the context. You went out of your
way to invent a reason to vent.

"Study finds some significant differences in brains of men and women":
[http://www.sciencemag.org/news/2017/04/study-finds-some-
sign...](http://www.sciencemag.org/news/2017/04/study-finds-some-significant-
differences-brains-men-and-women)

[https://stanmed.stanford.edu/2017spring/how-mens-and-
womens-...](https://stanmed.stanford.edu/2017spring/how-mens-and-womens-
brains-are-different.html)

[https://www.psychologytoday.com/blog/hope-
relationships/2014...](https://www.psychologytoday.com/blog/hope-
relationships/201402/brain-differences-between-genders)

It does not even matter how accurate any of those articles are, this just
serves to show that the claim made by OP is wrong. There are plenty of science
articles about differences.

So what exactly is the basis for your claim again? Did you do _any_ research
of your position at all (and just googling quickly before posting already
counts)? It seems to be entirely made up.

> made up opinion

Such as yours? :-)

~~~
cm2187
Talking about making up your own invented antagonistic positions: I am not
arguing everyone else pretends there are no difference, I am arguing that some
do. Quoting some articles arguing that there are differences doesn't prove
anything. As for the ad hominem arguments,...

~~~
Karnickel
> I am arguing that some do.

What is the purpose of finding someone, _anyone_ , who holds some fringe
opinion to attack it as if its common? You can find _any_ opinion about
anything out there after all.

> Quoting some articles arguing that there are differences doesn't prove
> anything.

It proves that the opinion you attack does not seem to be the opinion of the
scientific community. Unfortunately you did not include a single link to show
whom or what exactly your comment is about.

I hope you don't consider it rude or an "attack" that I point out that you did
not point to anyone/anywhere specifically? Because you really did not. I think
your argument would benefit greatly from being more specific.

I have Facebook friends _(who I keep because they are ex colleagues and mostly
harmless otherwise)_ whose whole life (judging by their news feed) seems to be
centered around finding the most stupid comments on the entire Internet and
then posting them to show how stupid they are. Your comment strongly reminds
me of that phenomenon. Personally, I consider it not only highly illogical but
also a huge waste of time, not to mention what it probably does for your
outlook on life to concentrate on the most absurd and ridiculous fringe
opinions that you can find.

Also, counter to your latest claim, you make no such distinction at all. You
attack the position as if it's common. The Facebook friends I mention at least
include specific links that they attack. Not that that would make much sense
given that we are here discussing a specific article.

