Yale study - Autism has always been part of evolution

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our knowledge, the current findings provide the first genome-wide evidence for the strong presence of natural-selection signatures in the systems genetics of ASD. Although many authors hypothesized a strong involvement of evolutionary mechanisms in ASD and several studies investigated candidate genes. no evidence of widespread positive selection on ASD-associated SNPs was previously reported. Using genome-wide data, we observed that common alleles associated with increased risk for ASD present a signature of positive selection in European populations. This strongly suggests that these variants have undergone positive selection during the course of human evolutionary history. Genetic correlation results support this hypothesis: ASD genetics (i.e., the set of risk variants that collectively–on a population level–influences ASD risk) strongly correlates with years of schooling, college completion, childhood intelligence, and openness to experience (S5 Table, data available at http://ldsc.broadinstitute.org/). Although these are robust genetic correlation results, further studies are needed to confirm the role of cognitive abilities in the evolutionary mechanisms involved in ASD genetics. However, multiple forms of evidence support that autism and high intelligence quotient share a diverse set of correlates, such as large brain size, fast brain growth, increased sensory and visual-spatial abilities, enhanced synaptic functions, increased attentional focus, high socioeconomic status, more deliberative decision-making, and high levels of positive assortative mating. Accordingly, the genomic signatures observed in ASD risk alleles could be due to their positive associations with cognitive ability. In 2012, the Center for Disease Control and Prevention reported an ASD prevalence of 1.47% in the US population (1 in 68 children; data available at http://www.cdc.gov/ncbddd/autism/data.html). These epidemiological data can be interpreted in relation to the recent studies regarding the genetics of ASD where common genetic variation explains 49% of the ASD heritability and inherited rare and de novo mutations account for only 6% . Considering rare variation, the strongest contribution seems to be played by de novo single nucleotide variants (SNV) and copy number variants (CNV) with a reduced (but still significant) contribution from rare inherited variants. In particular, rare variation associated with ASD is enrichened for disruptive truncating alleles. Accordingly, two different evolutionary mechanisms are likely to be present in relation to ASD genetics. Rare disruptive variants predisposing to ASD are under strong purifying selection (selective removal of deleterious alleles), as already observed in certain ASD genes. Conversely, genetic predisposition to ASD due to common variants is highly polygenic and, taken together on a population level, these alleles present beneficial effects with respect to cognitive ability. This positive selection for ASD risk alleles increased their occurrence in human populations, and this provides a possible explanation for the disease prevalence observed by epidemiological studies. A trait related to rare alleles under strong purifying selection should present much lower prevalence. Furthermore, we observed that common ASD risk alleles with evidence of positive selection are enriched for many biological processes related to developmental mechanisms and, in particular, to mechanisms related to nervous system development. This agrees with the strong evidence indicating that the processes related to human brain development are more responsible for distinctive human traits. Accordingly, ASD risk alleles could positively affect these mechanisms, causing better cognitive ability in carriers as a consequence. However, an excessive burden of these risk variants is correlated with the onset of the developmental disorders included in the autism spectrum as the evolutionary cost.

"However, multiple forms of evidence support that autism and high intelligence quotient share a diverse set of correlates, such as large brain size, fast brain growth, increased sensory and visual-spatial abilities, enhanced synaptic functions, increased attentional focus, high socioeconomic status, more deliberative decision-making, and high levels of positive assortative mating."

'Multiple forms of evidence' - No, there is NO evidence for the claims made in the quote above. The belief that 'autism' and high intelligence go together is a myth just like the belief that those who are 'on the spectrum' also lack empathy. 'Large brain size'??? Seriously? 'High socioeconomic status' - okay, this is a joke. It has to be. How can this particular claim possibly be true when, according to some, about 70 to 85 percent of us are either unemployed or underemployed?

"However, multiple forms of evidence support that autism and high intelligence quotient share a diverse set of correlates, such as large brain size, fast brain growth, increased sensory and visual-spatial abilities, enhanced synaptic functions, increased attentional focus, high socioeconomic status, more deliberative decision-making, and high levels of positive assortative mating."

'Multiple forms of evidence' - No, there is NO evidence for the claims made in the quote above. The belief that 'autism' and high intelligence go together is a myth just like the belief that those who are 'on the spectrum' also lack empathy. 'Large brain size'??? Seriously? 'High socioeconomic status' - okay, this is a joke. It has to be. How can this particular claim possibly be true when, according to some, about 70 to 85 percent of us are either unemployed or underemployed?

"However, multiple forms of evidence support that autism and high intelligence quotient share a diverse set of correlates, such as large brain size, fast brain growth, increased sensory and visual-spatial abilities, enhanced synaptic functions, increased attentional focus, high socioeconomic status, more deliberative decision-making, and high levels of positive assortative mating."

'Multiple forms of evidence' - No, there is NO evidence for the claims made in the quote above. The belief that 'autism' and high intelligence go together is a myth just like the belief that those who are 'on the spectrum' also lack empathy. 'Large brain size'??? Seriously? 'High socioeconomic status' - okay, this is a joke. It has to be. How can this particular claim possibly be true when, according to some, about 70 to 85 percent of us are either unemployed or underemployed?

Do you mind if I ask if you yourself are on the spectrum?

There is plenty of evidence, you just chose to ignore the study for a portion of the quote, which you also completely misinterpreted as it's not saying autism is correlated with high intelligence, but that the two are correlated with various common factors.

You can ask, but obviously you have doubts for some reason that I actually am. Do I sound like an N.T.? Maybe, after all these years, I'm starting to change and become more like the people I associate with.

No, I don't doubt that you're an Aspie. I just wondered why you should have a negative attitude against your brother and sister Aspies.

I wouldn't say we are sisters and brothers because we are aspies.

No, I don't doubt that you're an Aspie. I just wondered why you should have a negative attitude against your brother and sister Aspies.

Its an extremely complex read it looks like.

But it sounds like they are saying what I have sometimes wondered about-that autism is a by product of other trends in evolution. Trends driven by positive natural selection (like increased intelligence, or increases in certain kinds of intelligence).

Maybe it's just the way I write, the words I use, because this isn't the first time I've been called negative. I try to be neither a pessimist nor an optimist, but rather a realist. Maybe it's not working (oops, I'm being negative again). It is also true that I really, REALLY do not like being "an Aspie", for reasons too long, boring and personal to go into here. Maybe the bitterness is showing.