Origin of autism

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I think the mantra "parents have the right to raise their children as they see fit" is sacrosanct. Period.

That being said, it's OK for people to express opinions and discuss. And this came out a few days ago.
http://news.nationalgeographic.com/news/2015/01/150129-public-opinion-aaas-health-education-science/

Quite a number of scientists (even some doctors that I know) have refused vaccines for their children. To me, their number is low enough that it's not an overall concern. Personally, as a scientist myself, I make sure my children's immunization shots are up to date. What other parents want to do with their children, it's up to them. Parents make decisions, good or bad, and they will have live with those decisions for the rest of their lives.

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As for cause of autism, I just have to chuckle. Autism has been with us since forever. It's not something new. In some of the meetings I have attended I even become aware that some families have autism running in the family for three generations. What's new is people are marrying late and having babies late. To me, that's one of the few *statistical* correlation about autism. (Statistical, because there are surely autistic children from young couples.) Another solid correlation is autism is linked to ("comorbid with") weak muscle tone.

Now hold on to your seat. Because here comes the best part, if you are interested in scientific discussion.

Gene propagation is a statistical game: there are 250 million sperm trying to fertilize one single egg, and as a recent study in 2012 has shown, the genetic variation of those 250 million sperm is just as varied as the entire society itself.

Evolution is never about the survival of an individual. Evolution is, and has always been, about the survival of a species. In the case of collaborative animals like humans, evolution is about the survival of specialized member subsets of the species.

If you google search for "autism in prehistory," you find serious scientific articles on this subject. It's not something new. Many scientists have already looked at this issue. I have already read a few articles in the past. Autism has been there since prehistory.

If autism has been with us at 1% to 2% level (actually should be even higher), that means it plays a statistically significant role in human genome encoding, and that also means that statistically it helps to the survival of the human species. Statistically, autism is therefore an advantage to the species, not a disadvantage. Once you understand that, you will have a whole different perspective on autism. Sure, there are low-functioning (or "underdeveloped" in my jargon) autistic adults that tend not to survive. But again, *statistically*, the autistic trait has survived in our species. It can only do so because statistically it offers advantage to the survival of the species, or clans within the species.

This means that in ancient times, a certain subset of humans that carried weak muscle tone, married late and had babies late, had an advantage of survival to propagate their offspring. If you think in this direction, the answer becomes apparent. Which humans don't get to find a mate at normal/typical marrying age, yet they do prosper later in life? In ancient times, brute force was what mattered. For male humans, if you don't have brute force, you don't get mates. But there were exceptions. Which exceptions?

Let's face it, humans have been on earth for about 200,000 years. Yet civilization as we know it started only 6,000 years ago. Cave paintings are older: roughly around 30,000 years ago. Something changed around 6,000 years ago. Why did civilization all of sudden happen?

Humans have been socializing for 200,000 years and even earlier. But something happened 30,000 years ago, and then again 6,000 years ago. What happened then?

What happened was humans developed ways of bookkeeping. Using external visual aid to help them manage information, which later became written language. Now, what subset of humans excel at that task? What subset of human beings are patient enough for visual communication instead of verbal communication?

At least to me, personally, autism cannot be disentangled from civilization. As Temple Grandin has said in her book "The Way I See It: A Personal Look at Autism & Asperger's":

"If all the genes and other factors that cause autism were eliminated, the world would be populated by very social people who would accomplish very little." (I think originally she wrote something even stronger than this, but I won't quote that version.)

To me, autism comes from geeks. That's about it. Geeks with weak muscle tone that couldn't get mates. Geeks that somehow partnered up with, and was appreciated by, big-muscle and social guys: mainly because of the geeks' intellectual abilities. Geeks that were rewarded with mates later in life. And this formula of co-existence/symbiosis replicated itself throughout human history. Big-muscle and social guys without geeks were at a disadvantage with those with geeks: those without geeks tended to lose battles and be eliminated. Precisely because of their physical and social weakness, geeks tended to avoid conflicts in mating games earlier in life. For this subset of humans, their physical and social weakness contributed to their survival, and enhanced their chance of mating later to have offspring. Geeks married late, and their female partners tended to be older (in the old days this probably meant second marriage) and geeky, too, statistically speaking. (Though powerful geeks could get younger mates as well.) There is bound to be a difference between the impacts of father's age and mother age. Which is precisely what is observed in a recent study on autism. (Brian K. Lee, Drexel University School of Public Health). Father's age has a linear effect on the probability of autistic children. Mother's age effect shows up only after above 30.

If people are staying longer in school, switching to jobs that require more intellectual skills than physical skills, marrying late and having babies late. What do you expect about the relative proportion of autistic children in the society? After three generations, the "compounded interest" comes in truckload.

Autism is part of the plan of Mother Nature. It was decided that way, long ago. Autistic children are designed to specifically adapt to our modern society: they have an edge in the technological world. (Again, this is statistically speaking.) Autistic children are born to excel in technology. So the key is to raise them, ehem, obviously, with technology.

Two more points. In humans, a certain fraction of them are naturally immune to HIV manifestations. In ancient times, if there were an outbreak of AIDS, evolution would handle it by letting 95% of the population die, and the remaining 5% are automatically immune to AIDS, as all their future generations. Another point, it is known that the same genetic trait that causes an allergic disorder known as G6PD deficiency, also provides its carriers an enhanced immunity to a certain type of malaria. That is, often there are two sides to the same coin: what you see as a weakness, actually is an advantage in other areas, for the survival of the species. Mother Nature designs humans so that humans as a species can survive the most unpredictable future environments. For those researchers who think they are smarter than Mother Nature, think again. Mother Nature plays with more DNA molecules than the total memory capacity of all our supercomputers, combined.

One day we might be able to outsmart Mother Nature. But for now, we are not there, yet. As for all those studies to find "the cause of autism"? I am not a believer of any of those studies. I just don't think those researchers are as smart as Mother Nature. Just my personal opinion.

"Parents have the right to raise their children as they see fit." My choice is to communicate with my children, visually. So I draw pictures and make cartoon-like video clips for my children. And my children are always happy and smiling. Whether other people want to help their children by avoiding vaccines, it's none of my business. It's a free information world. Parents make decisions, parents live with the consequences. That's all.

I think there's a basis to what you say. It took a most odd and innovative mind, say, to come up with the wherewithal to conceive of the concept of agriculture. One had to have time away from survival activities to conceive this. I believe the leader of the group was smart enough to see the potential in exempting this (possibly autistic) person from the hunt, thus allowing this person enough space to come up with innovations, which would be relayed in fire gatherings after the completion of the hunting/gathering of the day.

I extend your line of thinking too include the entire genome.

eg. Down Syndrome, You have to remember that not all the males are successful at matrimony.
It's a cruel thing to say, that sometimes what looks to be disadvantageous in society, may actually be advantageous in other scenarios.

Down syndrome is not a visible condition amongst the cave people: It's just another person to them, and, if anything, with promiscuity, a down syndrome person would have been prized. In those days, it may have been called up sindrome!!

Consider if there was a virus that wiped out all of humanity except for the upsin people. Too an observer there would be no major difference in the manner in which society would unfold. If anything, it would save the planet to an extant.

There are other parts of the entire evolutionary genome that we would have no idea the purpose of -- EVEN WITH FULL CALCULATION, it is impossible to consider all possible states that our genes may have to accommodate in the environment.

eg. Maybe somewhere, what looks tobe a disease today, is actually rocket powered feet (astroboy) in the future.

I sometimes wonder what cancer is all about.

Please forgive me for rebutting:

Alas, I believe people like Cro-Magnon Man might have committed infanticide if they discerned signs of Down Syndrome. Also, if the baby wasn't considered "defective" at birth, it probably would have difficulty among other Cro-Magnon children as far as perceived adaptive skills are concerned. These people lived a hard life, and probably did not take kindly (unless moved by altruism), to having an extra mouth to feed who was seen as being "useless."

At least, if a child showed signs of Asperger/autistic type thought patterns, they might have been taken for "special training," perhaps of a spiritual nature. They might have been exempt from the hunt so they could use those faculties which they found "useful." They, perhaps, would have been seen as "unusual"--but "unusual" in a "useful" sense.

The first half (roughly) of this paragraph seems male-centric.
The second half contains a lot of assumptions. What is your evidence that these man-geeks married late, and that they married older women, and that these women were also geeky? Where is any of that recorded?

Man's earliest steps toward civilization occurred during the Holocene Climatic Optimum when they began to settle down in communities and farm instead of being nomadic hunters. It was helped enormously by the accidental creation of a hexaploid wheat by horizontal gene transfer when an additional set of chromosomes from a closely related grass to the early tetraploid wheat they had then.

Much of what followed was by necessity (necessity is truly the mother of invention) as people figured out how to do things better and more efficiently.

This seems largely based on conjecture. We don't know what marriage ages were across the last 30,000 years. It may have been that rich people/tribe leaders were able to marry first. It may have been that rich people/tribe leaders were less concerned about survival and therefore chose to marry later. It may have been random or something else entirely. We can't know whereabouts over the last 30,000 years genes for autism (of which there are numerous combinations) began to appear.

There's also some suggestion that marriage as we know it is a modern thing and that actually, years ago people would have serial monogamous relationships. Maybe people were procreating late because they just happened to have a new partner (and no birth control) and by chance the autism genes occurred.

One important point is that people with ASD don't hold exclusivity to innovative or scientific minds. There are many gifted NT individuals. It was not necessary for these inventions to have been developed by someone with autism.

Another is that 'mother nature' doesn't design people or survival of species. Random mutations occur. Sometimes these are helpful, sometimes these are not. Many of those that are not end up perishing but if for another reason the autistic genes were able to propagate, then autistics could survive without being deemed a necessary advantage.

There are no clear survival advantages of survival for deaf, blind, DS, etc people yet they've continued to survive. This isn't meant to malign this individuals - I'm hard of hearing myself and am quite comfortable with self-value separate from whether or not I'd be optimal in Darwin Games.

This is all wrong.

Evolution cannot directly work on populations as a whole. It can only work on individuals within those populations. The differences between the individuals in the population determine the different ways selection acts on the populations.

Although evolution can credibly be said to act on various levels, from ecosystems to genes, generally the smaller sets are more relevant. It's easier to understand evolution acting on individuals, but most accurately, it primarily acts on genes. There is no "grand plan". If something allows a gene to propagate but harms the individual or even the species, it will propagate.

Characteristics do not need to provide an advantage to survive. Sickle cell anaemia does not provide an advantage, for example. Rather, homozygous individuals ("carriers") have an advantage over unaffected individuals when malaria is present. Hazel coloured eyes do not provide an advantage, yet they propogate. Albinism doesn't provide an advantage. Downs syndrome doesn't provide an advantage. Klinefelter syndrome doesn't provide an advantage. There are all sorts of ways for neutral or even disadvantageous characteristics to not be lost.

This is what I was trying to say, I just couldn't think of all the words for it.

Quite true. Evolution is not about survival but about which genetic traits confer an advantage in reproduction and which genetic traits confer a disadvantage in reproduction.

Thanks.
(1) There are other grains (millet/rice in China, corn in the Americas). Wheat was just one of the choices, I would think.
(2) The prior interglacial (Eemian) had similar temperature characteristics, yet agriculture did not happen.
I would think something happened when humans first started to draw pictures. Agriculture is a non-genetic factor in human civilization, I would think. The "smart gene" for civilization probably predates HCO, since arguably agriculture in the Americas happened independently. Weather/needs could be drivers/triggers on the genetic component, but I would look at the relatively warmed-up period around 30,000 years ago. There is nothing new in looking in this direction (e.g. http://www.jaredreser.com/cognitiveparsimony/partseven.html ). The only thing new here is looking at the collaborative/symbiosis/statistical aspect as an explanation.

There are other grains, but none in a position to spread throughout the world as hexaploid wheat was able to do. Today, wheat is grown in many areas where rice and corn can not be grown and it is the number one source of plant protein in the world for humans. I don't think it is possible to overestimate the importance of wheat in the development of civilization. It didn't cause civilization, but it certainly helped enable civilization.

You mentioned the keyword: reproduction.



Autistic traits are inheritable. You can form a subspecies entirely of autistic people. When looking at evolution, you need to "close the loop" and look at the mating/reproduction step. So Downs and Klinefelter (and even others like Fragile-X, etc.) where fertility is impacted, is a different class of issues. One needs to make this distinction first. Also, Downs/Klinefelter/Fragile-X are all at chromosomal level. When things happen at that level (and provided reproduction is feasible), we are almost crossing the boundary of species.

Eye colors, albinism, etc. may or may not be advantages. Having a nose on top of your head may or may not be advantageous. But (a) combat uniforms of the military in Middle East or Southeast Asia: camouflage certainly is a factor. Light skin color in Northern Europe did not happen for no reason. (b) Having a nose on top of your head enabled mammals like whales and dolphins to live entirely underwater. Eye colors and albinism are inheritable. They've been with us for a long long time. I wouldn't go as far as to claim they "don't provide an advantage." My position is: Mother Nature works with so many DNA molecules and so much information, I am a scientist and I am humbled by her super-computing power. It's naive and dangerous to claim you know everything about her and that you are smarter than her.

Yes, mutations happens everyday. Cancer is prime example. When it happens to gametes, that's where evolution comes into play. 250 million sperm fertilizing an egg, and the genetic variation in 250 million sperm is tremendous. It's statistical in nature. In math this corresponds to the "multi-armed bandit" problem http://en.wikipedia.org/wiki/Multi-armed_bandit. There is always a decision to make about exploration vs. exploitation. Most of the times the reproduction loop is not closed. Cruel as it may be, that does not stop Mother Nature from exploring.

regards,

I'm sorry but you're making a huge number of assumptions and generalizations here. The answer to your question of why did civilization all of the sudden happen is simple: Population growth.

It did not happen 'suddenly' either. Before the agricultural revolution the hunter-gatherer groups were small and spaced far apart (each group had a large territory) and their population was kept in check by what you can call natural forces...primarily access to food, predators and disease. When agriculture began in the middle east, it brought with it the means to support a larger population which went from being mobile to steadily settling down (first agricultural groups planted fields and moved on then returned to the fields when it was ready to harvest) until they became permanently settled. Once settled their populations grew to the point where there was excess population in terms of labor... aka if a field could be tended by 10 people and you had 15 then you had 5 who had little to do. This excess population brought upon the beginnings of specializations (craftsmen,etc...those whose work was not directly related to securing food and shelter).

Over long periods of time the larger the population grew the more specialists it could have. Growing populations required more territory and it wasn't soon after until there simply was no more land to 'take' as going in any direction meant you'd find other human groups already settled in it. Now humans were primarily competing with other humans for resources. This is what we see roughly ~9kya where populations start to show signs of violence (constant) and villages start to change in design to be defensible (walls/fortifications) and for the first time we see evidence of a new specialization: soldiers/warriors (as evidenced by barracks being built inside villages). Women around this time become vital resources and it is said this is where 'male domination' begins (villages also house women in separate, protected buildings near the barracks and skeletal remains show women around this time stop showing evidence of being involved in work outside 'domestic' aka weaving, grinding food, etc... no longer seen with markers seen earlier that matched male skeletons that meant both sexes were equally involved in their daily work lives).

It is in this time period that the 'big leap' in advances starts. By competition between these villages there are quick (relatively) changes to building style, metalworking, weapon tech, agricultural techniques... all because they HAD to use what they had more efficiently and then they had to protect it from other humans. The advances you mention...writing, arts, etc..using external visual aids to communicate with others have been used since pre-agricultural times (cave paintings for example..and tattoos and clothing decorations). During this period of intense competition and an increased population the transition to more organized forms of communication became necessary to TRADE with others.... to maintain social status and control... to be able to organize themselves better and thus survive.

This is not the work of the 1% of AS-like population sitting down and thinking it all up and handing it to the NT overlords. It is far more likely that highly social and smart individuals got together and out of necessity agreed that a little drawing meant 'fish' and many generations later others said 'this is stupid, we can't keep memorizing tens of thousands of little drawings for everything around us.. why not make a drawing for every sound our mouths make and build words by drawing them? F-I-S-H . Less drawings to memorize!!' .

I very much enjoyed your post.

Without delving into all the details or worrying about if there are parts I might not be 100% in agreement with this, I agree that it is absolutely clear that nature demands that a certain percentage of the population be "different," and every attempt to force changes in that formula is likely to backfire in one way or another.

I guess the keywords I meant to express are "Behavioral Modernity." Since "behavioral modernity" and "autism" don't happen together often enough in Google search, I though I might as well add a follow-up posting here.

Behavioral Modernity: http://en.wikipedia.org/wiki/Behavioral_modernity

Basically, there is a school of thought known as "Great Leap Forward" that subscribes to the idea that there was a genetic mutation around 50,000 years ago that lead human to develop modern tools and ultimately written language. I am just saying that that genetic mutation could be linked to the emergence of autism. There is nothing new in thinking in this direction.

Cave paintings arose around the same time: http://en.wikipedia.org/wiki/Cave_painting. The earliest painting discovered so far is located in Indonesia: http://www.bbc.com/news/science-environment-29415716, it's dated 39,900 years of age.

If temperature can serve as trigger of these paintings, then it would more-or-less make sense. Here is a chart of historical temperature (and CO2) relevant to that period:

There are two warmed-up peaks around 57,000 and 50,000 years ago, and then a plateau starting at 40,000 years ago and that ended around 30,000 years ago. I am not sure when the autistic trait happened exactly, but one of those three warmed-up periods could be the candidate time frames.

And here is another article regarding this subject: "Autistic spectrum disorder in prehistory" , Catriona Pickard, Ben Pickard & Clive Bonsall (2011) http://www.research.ed.ac.uk/portal/files/539348/2011_CAJ_Pickard_etal.pdf, it contains good list of references of work done in this direction as well.

I think these authors still had the old, simplistic view about genetic inheritance. The Stanford study (2012) on genetic diversity in a male's sperm http://www.the-scientist.com/?articles.view/articleNo/32389/title/Surprising-Sperm-Diversity/ fundamentally changed how we view diversity in human genome. That is, a male's sperm is not there to shape the offspring of a family, but rather the offspring of a society. Mother Nature designs the whole human society, not just separate individuals. The existence of autistic individuals cannot be studied in isolation to the rest of the society. The symbiotic effect *must* be taken into account. Otherwise it'll be hard to explain why weaknesses such as social ineptitude and physical shortcomings can turn out to be advantages for the survival, mating and reproduction of this subgroup of humans.

All in all, I still believe that my explanation has gone beyond all other existing explanations so far. It still might not be right, but it has gone beyond what everybody else has said. Hopefully one day we can collect enough prehistoric DNAs to make a call.