Human Brain Evolution: ASPM and FOXP2

The accumulation of small heritable changes within populations over time.

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Re: Human Brain Evolution: ASPM and FOXP2

#41  Postby Tyrannical » Jan 06, 2011 5:41 am

The Denisova fossil also has the modern human version of foxp2, just like neanderthal man does. That makes the origin of foxp2 prior to 250k -400k years ago.

Finding the human-specific substitutions in the Denisova sequence helps to narrow down the evolution of language in the human lineage. If both substitutions were present in the ancestors of the Neandertal-Denisova-African trichotomy, any selection associated with these substitutions must have occurred prior to the divergence of these hominins. By the timeline of Reich and colleagues [1], that would be prior to 250,000-400,000 years ago. Remembering that we do not really know the function of these substitutions, it suggests at least a novel adaptive environment for communication in humans during the early to mid-Middle Pleistocene. Given the evidence of humanlike hyoid and middle ear morphology at Sima de los Huesos, this Middle Pleistocene development of human communication ability may also be unsurprising.
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Re: Human Brain Evolution: ASPM and FOXP2

#42  Postby Vosje » Feb 13, 2011 9:08 am

jez9999 wrote:
trubble76 wrote:
jez9999 wrote:But if our success is short-lived, it will surely be because we destroy ourselves through war or destroying the climate. It won't be for 'baser' evolutionary reasons that we've been out-competed by other species. The fact that only one thing like the human brain has ever evolved is why I'm drawing attention to it as a massive evolutionary anomaly, without precedent, that's hard to explain scientifically.

Evolution doesn't care (for want of a better word) whether we become "unfit" through competition or through self-inflicted reasons, there is no difference.
I agree that the human brain is an anomaly and without precedent, but I don't think it necessarily follows that it's scientifically difficult to explain, no more than other bits of our body. Perhaps you could specify which aspects of human brain evolution that you consider to be the most problematic and maybe we could take a look?

Our development of incredibly advanced speech, ability for abstract reasoning, future planning based on knowledge of past events, and a very advanced development of art and culture. All of these seem like big advantages to humans now, but it's hard to see them developing in a slow, incremental, evolutionary way.

I think it's just a selection that progressed and escalated over time. In the old days the tribe leader, the boss, was the one with the best pick of the women. The tribe leader, the king, could have had more than one wife plus a series of concubines, just because he was the man in charge. And who got to be king? That wasn't just a matter of strength, but one of intelligence and tactical skills. Why you and not your older or younger brother or your overly ambitious cousin? The one who could make the best alliances, make the best decisions, get the best people to look after him, would have a better chance of getting to be boss around the village, no? And it also has an impact on which tribe gets to rule the area and which tribe gets to be enslaved or even annihilated. Those with the better generals tend to have the best chances and how often in history did a lead general or warlord get to be the next king?
So yes, intelligence and hyper intelligence are selected for because that brings a man higher on the social ladder and thus better chances to reproduce. Even today one needs intelligence to climb the social ladder, outwitting those trying to do the same and those above you.
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Re: Human Brain Evolution: ASPM and FOXP2

#43  Postby Grace » Jul 27, 2011 5:35 am

Wow setiman, I just spent 1 hour and 10 minutes watching that video of yours.

The brain is my passion, so I thoroughly enjoyed it and learned a whole bunch of new stuff too:
-- mglur5 antagonist for fragile x and autism
-- mglur5 agonist for schizophrenia
-- nicotinic CHRNA7 receptor antagonist for fragile x and autism
-- nicotinic CHRNA7 agonist for schizophrenia.
-- there is a connection to insanity and genius.
-- engineers are more likely to be autistic than schizophrenic.

Many humans place acceptance and worthiness on verbal skills, but Dr. Bernie Crespi says, "verbal skills did not transform our world, it was technoloty." (So there verbal stuck ups!)

The most exciting information for me was the work on the genome. Humans have 98.8% pairs identical to chimpanzees, but we have 99.7% pairs identical to Neanderthals who lived 38,000 years ago in Croatia.

After listening to Dr. Bernie Crespi, I have come to believe that Evolutionary Behaviorists, Neuropsychiatrists, and Neuro-endocrinologists are doing more for psychiatry than psychiatrists are capable doing. Psychiatric quackery is about 200 years behind medical science. Instead of using diagnostics and the scientific method, they use talk therapy, questionairs, and poly pharmacy.

Patients are known to exaggerate, distort, tell-half truths, cover up, and lie. What good is that?

Hopefully, some day soon, Psychiatric Medical Science and Research will take the place of psychiatry.
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Re: Human Brain Evolution: ASPM and FOXP2

#44  Postby Atheistoclast » Sep 17, 2011 9:31 pm

I hereby contend that the scientific evidence for evolution of brain size and language development is suitably solid.

Except that I just performed an alignment using BLAST of human and chimp peptide sequences for ASPM.


Score = 7091 bits (18399), Expect = 0.0, Method: Compositional matrix adjust.
Identities = 3443/3477 (99%), Positives = 3457/3477 (99%), Gaps = 0/3477 (0%)

The number of differences is 1% - this is not unusual. Most of them would just be the result of neutral mutational pressures.

I also compared the human and macaque (rhesus monkey) sequences:


Score = 6777 bits (17583), Expect = 0.0, Method: Compositional matrix adjust.
Identities = 3333/3480 (96%), Positives = 3407/3480 (98%), Gaps = 4/3480 (0%)
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Re: Human Brain Evolution: ASPM and FOXP2

#45  Postby lucaspa » Oct 07, 2011 7:00 pm

Tyrannical wrote:

The Denisova fossil also has the modern human version of foxp2, just like neanderthal man does. That makes the origin of foxp2 prior to 250k -400k years ago.

From the original paper: "The phalanx was found in layer 11, which has been dated to 50,000 to 30,000 years ago." That sample is not much older than the samples of the neandertal genome that were sequenced, if at all.

The paper says that the Denisovans are a sister group to Neandertals (and thus to sapiens) "Nevertheless, the picture that emerges from analysis of the nuclear genome is one where the Denisova population is a sister group to Neanderthals."

One way to have the same FOXP2 is to inherit it from a common ancestor. Humans and neandertals have a common ancestor about 800,000 years ago. Another way is for gene flow much more recently. Since it has now been shown that there was gene flow between neandertals and sapiens, there may have also been gene flow between Denisovans and sapiens. In fact, the paper does note that Denisovans contributed to the genes of Melanesians. So it is possible that FOXP2 is less than 100,000 years old and was passed by sapiens to both neandertals and Denisovans.

By the timeline of Reich and colleagues [1], that would be prior to 250,000-400,000 years ago.

I don't see a timeline like that in the Reich et al. paper.
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