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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 Ca

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

lobf 9y ago
Isn't gene expression dependent on environment though? Is there some reason to believe that these differences are inherent, and not the result of gene expression being affected by the environment?
- astebbin 9y ago
  IANA biologist. That said, if by "inherent" you mean primarily genetically determined, I'd say that explanation seems most likely given the evidence.
  - lobf 9y ago
    >primarily genetically determined Even this statement isn't as absolute as you seem to think it is. Your genes may or may not express based on the environment in which you grow up. Primarily genetically determined doesn't make sense, since genes aren't working in a vacuum.
- TheAdamAndChe 9y ago
  > Is there some reason to believe that these differences are inherent, and not the result of gene expression being affected by the environment? That is a question that remains to be answered, and is only just beginning to be looked into through research on epigenetics[1]. [1] https://en.wikipedia.org/wiki/Epigenetics https://en.wikipedia.org/wiki/Epigenetics
  - why42 9y ago
    If our brain structures were different (at least in so far as the organization or distribution of cells within the cranium and not the external measurement) then one would expect adopted children from places where brains are very different to perform differently then peers in new locations. Yet I remember reading a study that showed that black children from Africa adopted by white parents in Germany performed at the same level as their peers. There have been other such studies with very similar conclusions.
    - ankjl 9y ago
      It could also be that differences in academic performance (I'm assuming academic is the performance you were referring to in your comment) are not accurate metrics for identifying the effects of differential brain organization. In scenarios like that, it's also difficult to control for the impact of different level of support for students in academic matters. For example, focused support for under-performing students compared to relatively relaxed support for students meeting expectations. I could probably also see the impact of different psychological factors associated with being adopted by a family on a different continent being hard to control for.
      - why42 9y ago
        My rambling brain confounded a few studies I had read. My mistake. I was incorrect about the study being related to adoptions. It was actually something interesting that happened in Germany. I had read an environmental interpretation of the Eyferth Study: https://en.wikipedia.org/wiki/Eyferth_study https://en.wikipedia.org/wiki/Eyferth_study
kakarot 9y ago
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)
- taneq 9y ago
  What do you mean by "get in check"? It's pretty well accepted that we deal differently with different species. We'll need to decide what counts as ethically acceptable, but blind insistence that "all humans are created equal" isn't going to fly when we have undeniably different species of human.
  - kakarot 9y ago
    I mean racism needs to be obliterated before the differences our governments and world religions trick us into bickering about become even greater, and we regress on fair and ethical treatment of all people in both the eyes of the law and the heart of the common man.
- tomrod 9y ago
  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).
kingkawn 9y ago
Sounds much more like science revealing its still-lingering capacity for producing racist hierarchical judgements of human anatomy
- astebbin 9y ago
  I honestly can't tell if this comment is satire. If it's not, please point to the racism. The study makes no moral judgement as to whether it's better to have a bigger parietal lobe vs. visual cortex. Do you think the study's results are somehow inaccurate, or improperly obtained?
x2398dh1 9y ago
From the article: > Only fossils younger than 35,000 years show the same globular shape as present-day humans and > They used state-of-art statistics to analyze endocasts of various fossils and present-day humans. There's nothing uncomfortable about this. They analyzed modern day humans and compared it to humans 35k years ago and found a statistical difference. "Uncomfortable" thoughts fall into the category of pseudoscience which has been long discredited - phrenology, essentially.
anentropic 9y ago
Is this any different to the "taxi drivers have bigger [part of] brains" or "musicians have bigger [part of] brains" memes that go around? i.e. true but insignificant

lobf 9y ago

Isn't gene expression dependent on environment though? Is there some reason to believe that these differences are inherent, and not the result of gene expression being affected by the environment?

astebbin 9y ago
IANA biologist. That said, if by "inherent" you mean primarily genetically determined, I'd say that explanation seems most likely given the evidence.
- lobf 9y ago
  >primarily genetically determined Even this statement isn't as absolute as you seem to think it is. Your genes may or may not express based on the environment in which you grow up. Primarily genetically determined doesn't make sense, since genes aren't working in a vacuum.
TheAdamAndChe 9y ago
> Is there some reason to believe that these differences are inherent, and not the result of gene expression being affected by the environment? That is a question that remains to be answered, and is only just beginning to be looked into through research on epigenetics[1]. [1] https://en.wikipedia.org/wiki/Epigenetics https://en.wikipedia.org/wiki/Epigenetics
- why42 9y ago
  If our brain structures were different (at least in so far as the organization or distribution of cells within the cranium and not the external measurement) then one would expect adopted children from places where brains are very different to perform differently then peers in new locations. Yet I remember reading a study that showed that black children from Africa adopted by white parents in Germany performed at the same level as their peers. There have been other such studies with very similar conclusions.
  - ankjl 9y ago
    It could also be that differences in academic performance (I'm assuming academic is the performance you were referring to in your comment) are not accurate metrics for identifying the effects of differential brain organization. In scenarios like that, it's also difficult to control for the impact of different level of support for students in academic matters. For example, focused support for under-performing students compared to relatively relaxed support for students meeting expectations. I could probably also see the impact of different psychological factors associated with being adopted by a family on a different continent being hard to control for.
    - why42 9y ago
      My rambling brain confounded a few studies I had read. My mistake. I was incorrect about the study being related to adoptions. It was actually something interesting that happened in Germany. I had read an environmental interpretation of the Eyferth Study: https://en.wikipedia.org/wiki/Eyferth_study https://en.wikipedia.org/wiki/Eyferth_study

kakarot 9y ago

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)

taneq 9y ago
What do you mean by "get in check"? It's pretty well accepted that we deal differently with different species. We'll need to decide what counts as ethically acceptable, but blind insistence that "all humans are created equal" isn't going to fly when we have undeniably different species of human.
- kakarot 9y ago
  I mean racism needs to be obliterated before the differences our governments and world religions trick us into bickering about become even greater, and we regress on fair and ethical treatment of all people in both the eyes of the law and the heart of the common man.
tomrod 9y ago
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).

kingkawn 9y ago

Sounds much more like science revealing its still-lingering capacity for producing racist hierarchical judgements of human anatomy

astebbin 9y ago
I honestly can't tell if this comment is satire. If it's not, please point to the racism. The study makes no moral judgement as to whether it's better to have a bigger parietal lobe vs. visual cortex. Do you think the study's results are somehow inaccurate, or improperly obtained?

x2398dh1 9y ago

From the article: > Only fossils younger than 35,000 years show the same globular shape as present-day humans and > They used state-of-art statistics to analyze endocasts of various fossils and present-day humans. There's nothing uncomfortable about this. They analyzed modern day humans and compared it to humans 35k years ago and found a statistical difference. "Uncomfortable" thoughts fall into the category of pseudoscience which has been long discredited - phrenology, essentially.

anentropic 9y ago

Is this any different to the "taxi drivers have bigger [part of] brains" or "musicians have bigger [part of] brains" memes that go around? i.e. true but insignificant