A definitive cause for autism spectrum disorders (ASD) has remained elusive, although the best picture so far seems to be one of a mix of genetic and environmental factors. This suggests that any genes involved with the condition by necessity are being passed on from generation to generation. A new study now suggests that these genes are being positively selected for.
The study, published in PLOS Genetics[open,DOI:10.1371/journal.pgen.1006618][DX], looked at the prevalence of alleles, or gene variants, commonly associated with an increased risk of ASD. The researchers discovered that these variants were found in much larger numbers than would be expected by chance, and they suggest that this may be because they are also linked to other genes implicated in cognitive ability.
The authors write that this positive selection between the genes thought to contribute to autism and those that might promote intelligence may explain why autism is such a prevalent condition, especially when it seems like it would have been selected against during human evolution.
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @12:36PM (5 children)
A deficits in social communication and social interaction is conducive to a highly probable "reproductive dead end".
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @01:48PM (1 child)
Incorrect.
A sufficiently high population of "antisocial" humans could simply interbreed among themselves, as they do not see this as a negative selector.
And for the record: a lot of what normies/ungifted people consider social, isn't.
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @08:20PM
Agreed ^
Simply being around other people does not automatically make something a truly social activity. Also, a lot of "actual" social activity is simply superficial bullshit, circle-jerking into a sense of comfort that gives us some security in this insecure world.
(Score: 2, Insightful) by Anonymous Coward on Tuesday March 07 2017, @02:05PM
The researchers are saying that genes associated with autism were positively selected for. In other words, these genes are somehow beneficial for survival and reproduction, otherwise there would be mostly negative selection pressure. This is in direct contrast to your "reproductive dead end" hypothesis. Apparently whatever positive selection effect these genes have is stronger than the negative selection effects of autism disorders.
Now why would genes that tend to cause or increase chances for autism be beneficial to survival? The theory here goes that these genes have other effects beside the possibility for autism disorders, namely promoting intelligence. It could be the case that autism spectrum disorders are simply a side-effect/cost of higher cognitive function. In other words, the prevalence of autism in individuals could be strongly related to our intelligence as a species.
Also note that autism is a spectrum, not a binary condition. There are many people high on the spectrum, who have difficulties socializing or other issues, but who otherwise live perfectly normal lives and will never have an ASD diagnosis. It only becomes a problem (and is diagnosed as a disorder) when the autism traits are so extreme that they impede an individual's everyday life or functioning in society. I believe right now we are only seeing the tip of the iceberg, the extreme cases, but we are slowly starting to see more of it as we gain understanding of this spectrum.
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @07:09PM
Not necessarily. Maybe anti-social people have learned to live in the hills. Whenever a big war happens, they survive because the invaders are unlikely to go into the spooky hills to root out a small number of people.
(Score: 2) by ese002 on Tuesday March 07 2017, @07:52PM
A deficits in social communication and social interaction is conducive to a highly probable "reproductive dead end".
Only when extreme. The research suggests that genes that increase risk of autism also increase neural capacity. So, as long you don't get full hammer of autism, you get higher intelligence. That is a reproductive advantage.
The classic example of this effect is sickle cell anaemia> [sciencedaily.com]. Two copies of the gene results in a deadly genetic disease. But inheriting the sickle cell gene from only one parent improves resistance to malaria. Thus, the gene persists in areas with high incidence of malaria.
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @01:18PM (1 child)
then the vaccines are severely damaging the more intelligent of us? conspiracy, or just convenient coincidence for the ruling class?
(Score: 2) by q.kontinuum on Tuesday March 07 2017, @03:27PM
Unlikely. I'd expect that the ruling class considers themselves intelligent, qua Dunning-Krueger-effect [wikipedia.org].
Registered IRC nick on chat.soylentnews.org: qkontinuum
(Score: 2) by JoeMerchant on Tuesday March 07 2017, @01:30PM (3 children)
This theory has been suggested for the last 10-15 years: match.com caused the autism increase.
Anybody read the article deeply enough to find sample sizes? Anything less than thousands is not going to confirm or deny anything.
🌻🌻 [google.com]
(Score: 4, Interesting) by VLM on Tuesday March 07 2017, @02:08PM
Its a weird meme because buzzfeed tier media has been pushing it intensely endlessly repeatedly but the academics repeatedly see no evidence of it.
https://jamanetwork.com/journals/jamapediatrics/fullarticle/570079 [jamanetwork.com]
My hard sci fi book plot theory is its just an incident of socioeconomic change and cultural pre-disposition. So 1000 years ago a genetically predisposed turbo-engineer and his genetic kin were just peasant #1535 on the ole feudal estate, nobody cared if a few percent here or there were autistic as long as he could stack hay bales or whatever. Someone a bit on the spectrum isn't a real problem when working in the fields maybe he'd make an unusually good blacksmith apprentice, as for the ones far along the spectrum well infant mortality was extremely high and in those conditions mental illness does not exactly flourish. Turns out a disease of computer programmers and engineers is autism, well, NOW they got lot of money and attention and there's an "outbreak". Where it gets hard sci fi is maybe along the lines of Dune series in 500 years we'll discover that brains attuned to warp field space travel calculations are super susceptible to psychedelic addiction. Or maybe opiate addiction. Or they just need hyper consumption of caffeine or vitamin C to function. Today its just an underclass of homeless people talking to themselves on highway onramps but maybe 500 years from now thats the brain-type that designs starship engines. They got a rough next 500 years coming up, but it gets better after that.
Or if you want fantasy plot, miners would seem to have a competitive advantage with shortness and strongness and body hair for warmth, so you can act all surprised about how dwarfs look and live, but it makes sense, and you'd need a population highly disconnected and ignorant of dwarves to be mystified at why those people that mine the mithril and gold seem to trend toward looking kinda dwarfy.
Almost as if human biological differences exist or something. Which is politically unacceptable for some, so the hamster wheel spins up and we're subjected to "well, um, the most politically acceptable idea I can say is it must be chemtrails like alex jones says" or whatever.
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @02:24PM (1 child)
Anybody read the article deeply enough to find sample sizes? Anything less than thousands is not going to confirm or deny anything.
These the numbers you're looking for? I don't know how to interpret them, but the sample size seems quite large to me.
Phenotypic Trait | Sample size | Reference
Attention Deficit Hyperactivity Disorder | (ADHD) 2,064 trios, 896 cases, and 2,455 controls | 27
Autism Spectrum Disorder | (ASD) | 5,305 ASD cases and 5,305 pseudocontrols | 7
Bipolar Disorder (BP) | 11,974 cases and 51,792 controls | 26
Major Depressive Disorder (MDD) | 9,240 cases and 9,519 controls | 28
Schizophrenia (SCZ) | 36,989 cases and 113,075 controls | 23
Source:
Original text http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1006618/ [plos.org]
S6 Table. Details of the GWAS summary statistics used in the present study.
(Score: 2) by JoeMerchant on Tuesday March 07 2017, @04:10PM
Thanks - 5000 is large enough to draw some conclusions, if the data cooperates.
🌻🌻 [google.com]
(Score: 1, Interesting) by Anonymous Coward on Tuesday March 07 2017, @03:51PM
Read Vernor Vinge's A Deepness in the Sky, he predicted all of this over a decade ago.
(Score: 2) by stormwyrm on Tuesday March 07 2017, @04:22PM (3 children)
The criteria of what constitutes autism has just expanded over the years, and diagnosis has also gotten more aggressive. We weren't looking as hard for autism in the past. The harder you look for something, the more of it you will tend to find, and you'll find even more of it if you broaden the criteria of your search.
http://scienceblogs.com/insolence/2017/01/25/another-reminder-that-there-is-no-autism-epidemic/ [scienceblogs.com]
If there was a genetic selection for autism, it likely took place a lot longer than a mere decade or two ago. It literally takes generations for genetic selection to happen, so the timeframe is more like centuries.
Numquam ponenda est pluralitas sine necessitate.
(Score: 2, Interesting) by JoeMerchant on Tuesday March 07 2017, @05:33PM (1 child)
what constitutes autism has just expanded over the years
In-part, this is true. However, in the 1980s, Autism was a 1:2000 diagnosis, even applying today's diagnostic criteria to the population back then would not get you to the 1:68 rates we have today, or, alternatively, if you apply the 1980s diagnostic criteria to today's population, you'll get much higher than 1:2000 rates.
A combination of genetic and environmental factors have caused a change in the rate and severity of incidence. I think this is most dramatically demonstrated with displaced populations, like Africans relocated to the U.S. - in a single generation they see marked increase in autism symptoms, something they did not experience in their native environment. Within our own family, we've had "autism like" symptoms for generations, but the relative severity of the effects has taken a dramatic upturn for males born since 1970. As you say, this is too fast for simple genetics to explain.
🌻🌻 [google.com]
(Score: 0) by Anonymous Coward on Tuesday March 07 2017, @11:22PM
(Score: 2) by dry on Wednesday March 08 2017, @02:24AM
While they weren't looking for autism as hard in the past, they still noticed the dysfunctional. I got diagnosed as brain damaged due to shortage of oxygen at birth back when I was evaluated in 1967. During my sons diagnosis for basically the same symptoms, the Doctors and researchers were very interested in the relationship between my son and I, as in blood samples for genetic tests and they seemed to just automatically accept that I'm autistic.
(Score: 2) by Subsentient on Tuesday March 07 2017, @10:05PM
"It is no measure of health to be well adjusted to a profoundly sick society." -Jiddu Krishnamurti
(Score: 2) by DutchUncle on Thursday March 09 2017, @05:40PM
Conjecture: A wild creature, especially prey, needs to be totally ADHD about noticing all the possible threats all around, while gathering food at the same time. That doesn't leave much time for contemplation, research, concentration; but then , those abilities aren't being selected for either. A wild predator needs patience and focus, but still isn't building much for the long term. By comparison, the abilities to focus on details and maintain concentration are needed to develop civilization and intelligence (as we tend to recognize it). So, yes, they are desirable traits, for some range of intensity; and this increases as civilization allows for the development of specialists (metalworking, construction) requiring deeper concentrated study. Too much, though, veers towards some variety of OCD or the autistic spectrum.