On the relationship between autism and evolution

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"Because you might have understood the word "lesion" but not "autism" or "brain"."

Why would you assume I do not understand these words?
Are you going to back up your accusations at all?

Because your statement was inaccurate. Autism has everything to do with brain lesions.

What if we replaced "hit on the head with a sledgehammer" with "deprived of oxygen in the womb for some reason"?

Please, people, forget about the sledgehammer bit. That wasn't my point.

My statement was not inaccurate.

Be honest; you felt threatened by my responses to your ridiculous "sledgehammer" comment, and made a sloppy attempt to establish your intellectual superiority by insulting me. Tsk, tsk.

If you think autism isn't the behavioral manifestation of brain lesions (abnormalities), then you're wrong.

I do not feel "threatened" by a lack of understanding.

What a shame that this thread has already been derailed by ancillary argument.

...General?

I have no idea what you're talking about. What's your argument?

Thanks.

Bluefin, perhaps you should try to clarify what you find objectionable about my post.

Define lesion.

Lesions usually are something like scarring or changes do to some process that changes the cellular structures in a negative way. . Are some of the hyperplasticity things found considered lesions? Aren't some of these microstructural differences just that - differences? I suppose I'm splitting hairs, but a structural difference isn't necessarily a lesion.

Let us gloss over the sledgehammer issue as saying that it is possible to damage an NT brain in such a way as to cause similar impairment of social interaction and other symptoms of AS. It is definitely possible to (disturbingly easily) damage those processing centers which allow one to recognize faces, emotions, verbal cues, etc. While one could not call the resulting condition "autism" proper, it would definitely be similar in effect: they could act in a manner indistinguishable from someone with an autism phenotype.

Consider Phinneas Gage, or the many curious victims of brain trauma in Oliver Sacks' works.

I recommend reading Oliver Sacks' The Man Who Mistook His Wife For a Hat, to find how even small brain trauma can produce frighteningly pervasive effects. It would not surprise me if there have been cases of a specific injury reproducing the symptoms of any recognized mental illness.

As I said, "lesion" is a very broad term in the world of medicine, especially when it comes to the brain, and can be applied to any "abnormality"--including hyperplaticity.

And you are splitting hairs--not that you don't have a point, but, where do you draw the line? When does it stop being a "difference" and start being a "negative" trait"? The truth is, there is a meaningful, general continuity and correlation between the concepts of "deviance" and "bad".

Meh. That's one reason the medical and psychiatric fields make me nuts. Terms are too fuzzy.

Deviance becomes bad at what point? Without deviance there is no genetic 'experimentation' with potentially beneficial change. Unfortunately, too much of what is good or bad is embedded in cultural expectations and can't be objectified in any reliable way. This is where neurodiversity and autistic pride gain a foothold. It is not entirely unjustified either. A great deal of my difficulty with executive functioning is simply that I don't parse time into the 8 hour days pushed by this culture. I don't have a dysfunctional view of time until it has to mesh with a world that has a substantially different view of it. And this micromanaged time is very new in terms of human culture. A pocket watch was a rarity except among the wealthy as late as a few hundred years ago. That's nothing in evolutionary scales.

I think autism may be akin to the first fish that started to grow feet instead of fins. While that mutation would not have been very advantageous for an animal living in the open ocean, as the oceans receded and more land mass became available for colonization by developing species, there came a tipping point where feet (and the corollary ability to breath air) were VERY advantgeous. This opened up a practically endless amount of new habitat for creatures that could survive on land.

Any mutation can survive natural selection as long as it does not cause such a detriment to the individual's ability to survive that the individual never reproduces. Mutations that result in deviations (to use Poke's original word) that are so great that the individual who exhibits the mutation never reproduces do not persist in the population. Mutations that result in a behavior or structure that is clearly advantgeous can quickly become part of the norm of the population.

Current research is developing a theory of autism that includes a highly interconnected brain structure. While this has yet to undergo extensive study in humans, rat models and imaging techniques are showing support for this theory. A highly interconnected brain structure could turn out to be a very advantgeous mutation. It appears that the "abnormal" (by today's standards) brain structure may be responsible for the extreme intelligence exhibited by many people on the spectrum however, it may also be the reason behind the extreme sensory problems and ultimately the reason why some autistics cannot communicate with people or otherwise generally interact with the world around them. I predict that if it were to become possible to abate the detrimental impact of sensory overload without interfering with the extreme intelligence, autism would become the new norm of the human population.

It might be helpful to remember that the point of my original post was not that "deviance = bad" in any intrinsic sense, but that natural selection rewards (and predisposes us toward) normality.

I would disagree - natural selection rewards advantage - if the environment changes, "normal" may become disadvantgeous in a big hurry!

The problem is that, again, autism is a heterogeneous condition, and even though some autistic brains are "highly interconnected", any given autistic brain is just a likely (probably more likely) to be "underconnected".

The fact that environmental change can deem "normal" traits disadvantageous has no bearing on whether or not natural selection has produced in us a predisposition toward normality in the meantime. It would just mean that the predisposition in question would no longer be useful.