12 ms·

Autism and Evolution

73 points by sajid 10y ago

Cozumel 10y ago
Similar: https://www.sciencedaily.com/releases/2016/08/160815064944.htm https://www.sciencedaily.com/releases/2016/08/160815064944.h... Schizophrenia emerged after humans diverged from Neanderthals
- T0T0R0 10y ago
  The incredible part about that detail would be that in any other animal much of Schizophrenia's symptoms would be subclinical, in that language and socialization expresses most of Schizophrenia's detriments. The paper is really about emergence and transmission of the disorder, and not so much about why humans find faults in those afflicted by it. But consider solitary animals, or apex predators. That they'd be schizophrenic, and construct distorted understandings of the world around them probably wouldn't matter, as long as they manage to hunt for food and produce offspring. No one would care about what a bear thinks of the origin of the universe, or how realistic its outlook of its own future is. I realize that Schizophrenia has other debilitating effects, but it also affects people in varying degrees.
- deleted 10y ago
  [deleted]
geggam 10y ago
So DNA is mutating... and we believe its evolution ? Then why are certain groups seemingly evolving at different rates ? https://en.wikipedia.org/wiki/Amish_anomaly https://en.wikipedia.org/wiki/Amish_anomaly Food ? Environment ?
adsfqwop 10y ago
I don't quite buy that autism will be shown to be genetic. I think it's an environmental factor. The rate of increase in autism is pretty much exponential: http://www.nature.com/news/2011/111102/full/479022a/box/1.html http://www.nature.com/news/2011/111102/full/479022a/box/1.ht... Now that's a very scary chart if you start to project that curve into the future. Here's another one. Not saying this is the cause, but it is a cause for concern. We have many similar patterns of environmental factors increasing with autism prevalence, which makes the likelihood of it being environmental stronger than something else. http://images.medicaldaily.com/sites/medicaldaily.com/files/styles/full_breakpoints_theme_medicaldaily_desktop_1x/public/2015/01/05/autism-prevalenceuse-glyphosate.JPG http://images.medicaldaily.com/sites/medicaldaily.com/files/... For example it took a long time to figure out that lead in gasoline could lead to cognitive decline. BPA and phtalates is another recent discovery, which cause hormone distruption. What else do we have today that is yet to be figured out, and what is the likelihood that we have something similar brewing that we do not yet know about.
- jarmitage 10y ago
  It is not prevalence that is growing exponentially, it is diagnosis.
- hoopism 10y ago
  I am not dismissing the idea that environmental causes may be at play... but be VERY VERY cautious when throwing around charts like that. http://www.snopes.com/medical/toxins/glyphosate.asp http://www.snopes.com/medical/toxins/glyphosate.asp Correlation != Causation and not every scientist is an expert on Autism/Genetics/Biology. "Even disregarding the sloppy mathematics, the claim's very basis (that glyphosate is the cause of a perceived increase in autism) is unsupported. No mention was made of how glyphosate was isolated and shown to be a cause (or even a factor) in some or any cases of autism in the article. No autism spikes near agricultural facilities were described, nor was any definitive causative link at all cited by the article (and presumably, Seneff) to back up the purported link between glyphosate and autism rates anywhere other than the imaginations of those making the claim. The single link of merit made within the article (to a USDA report) made absolutely no mention of autism at all but was misleadingly arranged to suggest a connection. What the claim seemed to hinge on largely was a correlation/causation fallacy: Because [unclear activity involving glyphosate] occurred, a corresponding rise in autism diagnoses must be due to that unspecified issue with glyphosate. Claims of a similar nature have been dispelled with graphs like the following that show how difficult (or simple) it is to "prove" any one cause correlates with any one effect:"
- kijin 10y ago
  It doesn't need to be one or the other. Genetics can predispose somebody to be more vulnerable to certain environmental factors. They will not show any symptoms unless those environmental factors are present, but there's still genetics involved. And of course there's this whole field called epigenetics that studies how the same genes can be expressed differently based on environmental factors.
- M_Grey 10y ago
  There are a lot of potential candidates... too many to be honest, and a lot of them are related to basic economic activities. History shows that environmental issues driven by economics aren't solved until an alternative comes along and is adopted; the problems of dead horses and horse dung in NYC streets were solved by... the automobile. I'm put in mind of the recent paper posted on HN regarding magnetic nanoparticles being found in human brains. Unrelated to autism (probably) is the increasing study of prions and in general, maladaptive protein synthesis. What isn't known about these issues could fill volumes.
i14ng 10y ago
The article says 1-5% of the ASD cases they looked at were related to the "HARs" (human-accelerated regions). The most important thing to understand about autism is that it isn't a single condition, but an umbrella category with a bunch of conditions grouped into it. It's a trait (trait cluster, really), analogous to intellectual disability or giftedness, rather than analogous to a condition with a single known cause like trisomy 21. See https://intellectualizing.net/2013/12/17/book-rethinking-autism-variation-and-complexity/ https://intellectualizing.net/2013/12/17/book-rethinking-aut... and https://intellectualizing.net/2015/06/04/why-it-matters-whether-autism-is-a-trait-or-a-unified-condition/ https://intellectualizing.net/2015/06/04/why-it-matters-whet... Once we understand that autism isn't a single condition, a lot of the ways the public (and researchers) talk about autism turn out to be kinda nonsense.
noipv4 10y ago
So are Asperger / ASD mutations, a step back, step forward, or a step in a different direction (evolution?)
- dragonwriter 10y ago
  Evolution isn't directed.
  - Spellman 10y ago
    And if there's no pressure to remove a particular trait from being in the reproductive environment...
  - ricksplat 10y ago
    It sounds as though you are speaking from the standpoint that genes mutate at random in all and any "directions" (net). However, non-successful genes are eliminated, so in the effective sense it is (gross). The direction of evolution is towards being "more suitable" for a particular environment.
- nickpsecurity 10y ago
  dragonwriter is right in general sense. We can evaluate it, though, from our own perspective. It's a step forward in terms of intelligence and stability in world. It's a giant leap backward in terms of success or happiness in a world of non-autistic people. Evolution would also consider it a negative in that autistics get laid and reproduce less than non-autistics. They also are more likely to loose in competition in corporations, battlefields, and jungles. So, it's a net loss overall for evolution's main function but autistics persist for one reason or another.
  - lets-tryagain 10y ago
    These comments are simply unbelievable. Autism is not a super power. Visit families with meaningfully autistic children and come back and tell me if you think it is a "step forward" in "intelligence and stability". These children will need to be institutionalized as adults.
nickpsecurity 10y ago
I went the other way with it: high-functioning autism is a component of more-evolved humans. The autistics are more rational, often less selfish in my anecdotal experience, and cause almost no harm to others vs baseline. A world full of them would've largely eliminated famine, pollution, war, violent crime. It would be a fraction of what we see. Further, autistics and introverts are often behind many great advances that push progress of our species forward. That would increase greatly. So, I've always thought of us as the next thing after homo sapiens. Jokingly call it Neosapiens from a cartoon as it was a cool name. Not likely to actually happen but a nice example of how the world might have been better. My ideal one, though, preserves the different types of people with two modifications: built-in mechanism where causing harm to others makes individual experience personal pain; built-in need to connect outside local sphere to reduce isolationism. These two would keep world more interesting than the safe, autistic one while also eliminating many problems. Just two, small changes in the brain.
- gertef 10y ago
  OTOH, a world full of people with autism might never be able to come together and build large group projects. Autism might work well for creating in the computer+Internet age (but I have doubts that non-autism traits are totally unnecessary), but much less likely to work in lower-tech society.
  - psyc 10y ago
    I don't know. I for one love working with people as long as the focus stays on the goal and not on interpersonal stuff.
  - nickpsecurity 10y ago
    "OTOH, a world full of people with autism might never be able to come together and build large group projects. " This was a problem for the Autreat conference. It was made by autistics for autistics. The coordination required to create it was a big problem. I wonder if things would get better if they were the norm. I'm not sure.
- wpietri 10y ago
slantedview 10y ago
There have been instances of biological twins where one winds up with autism and another doesn't. So to the extent that autism has a genetic component - it is just that - a component.
- azakai 10y ago
  That does support non-genetic factors to some extent, but the existence of such twins matters less than their frequency, because twins don't always have identical DNA (mutations can occur after they separate).
  - SomeStupidPoint 10y ago
    Also, even with identical DNA, that doesn't mean the twins will be exactly identical: if things like fingerprints are only very similar instead of exactly matching, then there's reason to think that the fine brain structure can vary as well -- perhaps enough to straddle sides of a disorder. So in addition to twin frequency, it would be worth analyzing twin spread: what is the variation in the behavior of twins (in the background), and is the spread in autistic/non-autistic twin pairs statistically similar, ie, are we just selecting for normal, expected variation that happens to fall close to a boundary?
  - gertef 10y ago
    If autism is caused by an individual mutation (not alredy present in the parent genome) it would be amazing that the mutation is so common, but not currently of a known form (like trisomy).
    - roywiggins 10y ago
      It could be that there are many genes and many mutations possible to cause it, which means two people with autism would almost certainly not share the same mutation. This would make it quite difficult to work out what the mutations are. (There is one mutation that causes something like autism, fragile-X)
- gertef 10y ago
deleted 10y ago
[deleted]
throwwit 10y ago
After spending some time with an individual that has autism, I feel like there's an underlying process to 'normal' cognition that spans a gamut from Schizophrenia to Autism. A shaky metaphor to the neurology might be how equivalent logic circuits can be made from corollary gates. It's as if one condition skews toward signal powered gates vs source powered gates. I.e. more concrete vs 'out there'... Just a quick thought.
- throwwit 10y ago
  (Forgot to explicitly say, the failure modes are different: an inactivation that inhibits gracefully (simply forgetting) vs activation independent of actual signal (spurious thought). False negatives vs false positives.)
deleted 10y ago
[deleted]
jokoon 10y ago
> Chimps are social creatures, but they’re different from humans. They don’t live in compact cities of a million people. That requires extraordinary social behavior.” I don't think cities are a result of social behavior, it's more the result of economic behavior. Cities are clusters of box apartments, which don't really demonstrate social behavior.

73 points by sajid 10y ago

Similar: https://www.sciencedaily.com/releases/2016/08/160815064944.htm https://www.sciencedaily.com/releases/2016/08/160815064944.h... Schizophrenia emerged after humans diverged from Neanderthals

T0T0R0 10y ago
The incredible part about that detail would be that in any other animal much of Schizophrenia's symptoms would be subclinical, in that language and socialization expresses most of Schizophrenia's detriments. The paper is really about emergence and transmission of the disorder, and not so much about why humans find faults in those afflicted by it. But consider solitary animals, or apex predators. That they'd be schizophrenic, and construct distorted understandings of the world around them probably wouldn't matter, as long as they manage to hunt for food and produce offspring. No one would care about what a bear thinks of the origin of the universe, or how realistic its outlook of its own future is. I realize that Schizophrenia has other debilitating effects, but it also affects people in varying degrees.
deleted 10y ago
[deleted]

geggam 10y ago

So DNA is mutating... and we believe its evolution ? Then why are certain groups seemingly evolving at different rates ? https://en.wikipedia.org/wiki/Amish_anomaly https://en.wikipedia.org/wiki/Amish_anomaly Food ? Environment ?

adsfqwop 10y ago

I don't quite buy that autism will be shown to be genetic. I think it's an environmental factor. The rate of increase in autism is pretty much exponential: http://www.nature.com/news/2011/111102/full/479022a/box/1.html http://www.nature.com/news/2011/111102/full/479022a/box/1.ht... Now that's a very scary chart if you start to project that curve into the future. Here's another one. Not saying this is the cause, but it is a cause for concern. We have many similar patterns of environmental factors increasing with autism prevalence, which makes the likelihood of it being environmental stronger than something else. http://images.medicaldaily.com/sites/medicaldaily.com/files/styles/full_breakpoints_theme_medicaldaily_desktop_1x/public/2015/01/05/autism-prevalenceuse-glyphosate.JPG http://images.medicaldaily.com/sites/medicaldaily.com/files/... For example it took a long time to figure out that lead in gasoline could lead to cognitive decline. BPA and phtalates is another recent discovery, which cause hormone distruption. What else do we have today that is yet to be figured out, and what is the likelihood that we have something similar brewing that we do not yet know about.

jarmitage 10y ago
It is not prevalence that is growing exponentially, it is diagnosis.
hoopism 10y ago
I am not dismissing the idea that environmental causes may be at play... but be VERY VERY cautious when throwing around charts like that. http://www.snopes.com/medical/toxins/glyphosate.asp http://www.snopes.com/medical/toxins/glyphosate.asp Correlation != Causation and not every scientist is an expert on Autism/Genetics/Biology. "Even disregarding the sloppy mathematics, the claim's very basis (that glyphosate is the cause of a perceived increase in autism) is unsupported. No mention was made of how glyphosate was isolated and shown to be a cause (or even a factor) in some or any cases of autism in the article. No autism spikes near agricultural facilities were described, nor was any definitive causative link at all cited by the article (and presumably, Seneff) to back up the purported link between glyphosate and autism rates anywhere other than the imaginations of those making the claim. The single link of merit made within the article (to a USDA report) made absolutely no mention of autism at all but was misleadingly arranged to suggest a connection. What the claim seemed to hinge on largely was a correlation/causation fallacy: Because [unclear activity involving glyphosate] occurred, a corresponding rise in autism diagnoses must be due to that unspecified issue with glyphosate. Claims of a similar nature have been dispelled with graphs like the following that show how difficult (or simple) it is to "prove" any one cause correlates with any one effect:"
kijin 10y ago
It doesn't need to be one or the other. Genetics can predispose somebody to be more vulnerable to certain environmental factors. They will not show any symptoms unless those environmental factors are present, but there's still genetics involved. And of course there's this whole field called epigenetics that studies how the same genes can be expressed differently based on environmental factors.
M_Grey 10y ago
There are a lot of potential candidates... too many to be honest, and a lot of them are related to basic economic activities. History shows that environmental issues driven by economics aren't solved until an alternative comes along and is adopted; the problems of dead horses and horse dung in NYC streets were solved by... the automobile. I'm put in mind of the recent paper posted on HN regarding magnetic nanoparticles being found in human brains. Unrelated to autism (probably) is the increasing study of prions and in general, maladaptive protein synthesis. What isn't known about these issues could fill volumes.

i14ng 10y ago

The article says 1-5% of the ASD cases they looked at were related to the "HARs" (human-accelerated regions). The most important thing to understand about autism is that it isn't a single condition, but an umbrella category with a bunch of conditions grouped into it. It's a trait (trait cluster, really), analogous to intellectual disability or giftedness, rather than analogous to a condition with a single known cause like trisomy 21. See https://intellectualizing.net/2013/12/17/book-rethinking-autism-variation-and-complexity/ https://intellectualizing.net/2013/12/17/book-rethinking-aut... and https://intellectualizing.net/2015/06/04/why-it-matters-whether-autism-is-a-trait-or-a-unified-condition/ https://intellectualizing.net/2015/06/04/why-it-matters-whet... Once we understand that autism isn't a single condition, a lot of the ways the public (and researchers) talk about autism turn out to be kinda nonsense.

noipv4 10y ago

So are Asperger / ASD mutations, a step back, step forward, or a step in a different direction (evolution?)

dragonwriter 10y ago
Evolution isn't directed.
- Spellman 10y ago
  And if there's no pressure to remove a particular trait from being in the reproductive environment...
- ricksplat 10y ago
  It sounds as though you are speaking from the standpoint that genes mutate at random in all and any "directions" (net). However, non-successful genes are eliminated, so in the effective sense it is (gross). The direction of evolution is towards being "more suitable" for a particular environment.
nickpsecurity 10y ago
dragonwriter is right in general sense. We can evaluate it, though, from our own perspective. It's a step forward in terms of intelligence and stability in world. It's a giant leap backward in terms of success or happiness in a world of non-autistic people. Evolution would also consider it a negative in that autistics get laid and reproduce less than non-autistics. They also are more likely to loose in competition in corporations, battlefields, and jungles. So, it's a net loss overall for evolution's main function but autistics persist for one reason or another.
- lets-tryagain 10y ago
  These comments are simply unbelievable. Autism is not a super power. Visit families with meaningfully autistic children and come back and tell me if you think it is a "step forward" in "intelligence and stability". These children will need to be institutionalized as adults.

nickpsecurity 10y ago

I went the other way with it: high-functioning autism is a component of more-evolved humans. The autistics are more rational, often less selfish in my anecdotal experience, and cause almost no harm to others vs baseline. A world full of them would've largely eliminated famine, pollution, war, violent crime. It would be a fraction of what we see. Further, autistics and introverts are often behind many great advances that push progress of our species forward. That would increase greatly. So, I've always thought of us as the next thing after homo sapiens. Jokingly call it Neosapiens from a cartoon as it was a cool name. Not likely to actually happen but a nice example of how the world might have been better. My ideal one, though, preserves the different types of people with two modifications: built-in mechanism where causing harm to others makes individual experience personal pain; built-in need to connect outside local sphere to reduce isolationism. These two would keep world more interesting than the safe, autistic one while also eliminating many problems. Just two, small changes in the brain.

gertef 10y ago
OTOH, a world full of people with autism might never be able to come together and build large group projects. Autism might work well for creating in the computer+Internet age (but I have doubts that non-autism traits are totally unnecessary), but much less likely to work in lower-tech society.
- psyc 10y ago
  I don't know. I for one love working with people as long as the focus stays on the goal and not on interpersonal stuff.
- nickpsecurity 10y ago
  "OTOH, a world full of people with autism might never be able to come together and build large group projects. " This was a problem for the Autreat conference. It was made by autistics for autistics. The coordination required to create it was a big problem. I wonder if things would get better if they were the norm. I'm not sure.
wpietri 10y ago

slantedview 10y ago

There have been instances of biological twins where one winds up with autism and another doesn't. So to the extent that autism has a genetic component - it is just that - a component.

azakai 10y ago
That does support non-genetic factors to some extent, but the existence of such twins matters less than their frequency, because twins don't always have identical DNA (mutations can occur after they separate).
- SomeStupidPoint 10y ago
  Also, even with identical DNA, that doesn't mean the twins will be exactly identical: if things like fingerprints are only very similar instead of exactly matching, then there's reason to think that the fine brain structure can vary as well -- perhaps enough to straddle sides of a disorder. So in addition to twin frequency, it would be worth analyzing twin spread: what is the variation in the behavior of twins (in the background), and is the spread in autistic/non-autistic twin pairs statistically similar, ie, are we just selecting for normal, expected variation that happens to fall close to a boundary?
- gertef 10y ago
  If autism is caused by an individual mutation (not alredy present in the parent genome) it would be amazing that the mutation is so common, but not currently of a known form (like trisomy).
  - roywiggins 10y ago
    It could be that there are many genes and many mutations possible to cause it, which means two people with autism would almost certainly not share the same mutation. This would make it quite difficult to work out what the mutations are. (There is one mutation that causes something like autism, fragile-X)
gertef 10y ago

deleted 10y ago

[deleted]

throwwit 10y ago

After spending some time with an individual that has autism, I feel like there's an underlying process to 'normal' cognition that spans a gamut from Schizophrenia to Autism. A shaky metaphor to the neurology might be how equivalent logic circuits can be made from corollary gates. It's as if one condition skews toward signal powered gates vs source powered gates. I.e. more concrete vs 'out there'... Just a quick thought.

throwwit 10y ago
(Forgot to explicitly say, the failure modes are different: an inactivation that inhibits gracefully (simply forgetting) vs activation independent of actual signal (spurious thought). False negatives vs false positives.)

deleted 10y ago

[deleted]

jokoon 10y ago

> Chimps are social creatures, but they’re different from humans. They don’t live in compact cities of a million people. That requires extraordinary social behavior.” I don't think cities are a result of social behavior, it's more the result of economic behavior. Cities are clusters of box apartments, which don't really demonstrate social behavior.