On the relationship between autism and evolution

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But genetic inheritance and being hit with a sledgehammer can result in exactly the same brain lesion(s). It's not the end result (condition) that's different, only the basis for it.

Of course, if you define autism from square one as "something that can only come about by genetic inheritance", well, of course you can't become autistic by being hit with a hammer. And, while this definition is based in reality to a large extent, it ignores the larger picture of what autism really is, as compared to where it came from.

Autism is not a brain lesion.

Except that there are no lesions in an autistic's MRI. A sledge hammer leaves more visible damage. Some advanced imaging techniques are showing evidence of structural differences, but autism appears to be more subtle than a direct brain injury.

This is true in some cases, but in a great many cases lesions are quite apparent.

http://www.google.com/search?hl=en&sour ... 1&aql=&oq=

http://scholar.google.com/scholar?hl=en ... a=N&tab=ws

Last edited by Poke on 29 Mar 2011, 8:07 am, edited 1 time in total.

No offense, but, might I suggest that you don't fully understand at least one of the words you just used?

In a sense, you're right, of course--autism isn't a brain lesion, it's the behavioral manifestation of brain abnormalities, to which the word "lesion" can be applied broadly.

Hmmm, that does make a lot of sense.

Although I think the ratio of ethics:laws of nature vary depending on your living conditions. In a place like America or Europe for example a lot of what we need is handed to us on a plate, and the way of life is very convenient with our electrical gadgets and warm houses. So we can afford to care for the vulnerable. and we can run care homes for the severely mentally disabled, and set up charities for them and keep ill people alive. And also of course the autistic people can live perfectly good lives.
But, when you go to places like the middle of the Amazon or in a small community in Kenya somewhere you notice the vast majority are physically healthy and with full mental capacities. And why is this? Well because the ill or ret*d people have died in childhood because they can't keep up with the pace of life. Of course the people are just as altruistic as the city people, but they also have the laws of nature putting pressure on them. When you live in the middle of the rainforest or desert and have to go out running after wild pigs for your food, you can't afford to be born with no legs or be totally blind. And if you're severely mentally ret*d or autistic you become a burden, I know that sounds really mean but when you live in the middle of nowhere it's hard for the rest of the community to look after you even if they do try hard. In these environments you still have the danger of famine, predators, poisonous creatures and severe injury (with no medical care to fall back on). And the unhealthy people are not going to cope.
I read in a book about anthropology there was a tribe a tribe where when a woman gives birth the other women checked the baby and if they weren't strong enough the baby would be abandoned, and if the baby looked strong they giver them to the mum. And when missionaries went over to this tribe to change their views on things that practice was banned. What ended up happening was that the same amount of kids died of illnesses as the babies that died at birth, keeping so many sickly kids alive in these harsher conditions just wasn't possible. And I'm sure the practice of checking newborns is still carried out today in some remote areas.

Last edited by MONKEY on 29 Mar 2011, 8:14 am, edited 1 time in total.

Great (and valid) observations, MONKEY.

Which word are you suggesting I do not understand?

I don't know--one of them, for sure.

If I had to guess, I would say "lesion", which in the world of medicine has a very broad definition. A "brain lesion" is ultimately just an abnormality of tissue. Of course, when it comes to the brain, the line between "organ" and "function" is blurred dramatically, and in cases where the underlying neurological abnormality isn't apparent by means of current measuring methods, it is assumed that the abnormality is simply too subtle to be measured by those methods--not that it isn't there.

These are the advanced techniques I was speaking of. In a standard MRI, there is little discernible difference. A sledge hammer lesion does not require a PET scan to be seen.

In which autistic person? In many cases, the abnormality is just as drastic and obvious as the one that might be produced by the ol' sledgehammer. The fact that we can't quantify the abnormality in some autistic individuals doesn't mean that it isn't dramatic and blatant in others.

Once again, a key concept here is heterogeneity.

We are getting way too caught up in this sledgehammer stuff, which was only a very minor aspect of my original post.

"If I had to guess, I would say "lesion", which in the world of medicine has a very broad definition."

Why would you have to guess? Either I have used the word incorrectly, or I have not.

Often not true. Being able to thrive with that handicap means you must be even better than the normal ones. Lots of animals practice this - humans included.

http://en.wikipedia.org/wiki/Evolution# ... _selection

When you define "too much" as "so much it's bad", duh Sometimes the extremes do better.

If you look at that link I posted, there's a picture of colored circles. It was selected for darkness, so all the circles became dark. What would have happened if you went for diversity instead? You'd get the entire spectrum of color. If then something happened to select for darkness, the dark ones would still survive, leading to basically the same result as selecting for darkness. But, if instead something happened to select for white, the diverse population would manage that just as easily, while the dark one would have a very hard time - maybe even going extinct.

Of course, helping people costs time & energy, so it's a tradeoff. (Goes well with the self-handicapping above.)

Probably they had it, but either the society was different so it wasn't bad, or in a milder version.

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

Was this added to see if anyone would actually read that far?

I am describing a very general pattern, the effects of which are cumulative. Not every instance or trait will adhere to it, of course.



Again, I am describing a very general pattern. Not every instance or trait will adhere to it, of course. But thanks for the "duh ", that was a nice touch.