Published on 12, July, 2020
Hello all
I was musing the other day on the roots of autism and two things struck me:
So both are potentially controversial theories and please we are trying to only look at scientific information and not conspiracy theories, my reason for saying this will become very clear in a moment.
Looking at the first point, whilst it had been comprehensively shown scientifically in multiple studies that there is not a direct link between vaccines and autism, and the original "research" that started that whole controversy was unscientific and unethical, there are still some important questions that remain. Autistics for instance, are far more likely than the neurotypical population to have a range of autoimmune medical conditions, such as Rheumatoid Arthritis, which is interesting as there is a small risk with every vaccination of an autoimmune reaction. Hence there is an interesting question as to why autistics are more autoimmune disease prone and does this make them more disposed to a vaccination reaction? So whilst they already had autism do the traits come out post vaccination due to an autoimmune reaction or is there not link or something more sinister?
As for two species, we know that all, but people of direct African decent, modern humans contain some neanderthal DNA. IS it possible though that autistics contain some other neanderthal DNA that makes them more neanderthal than human, hence two species in effect. We know that humans and neanderthals did copulate ad have cross-species babies, so its possible that they "live on". Think also what happens when one crosses a horse and a donkey, so what happens if one crosses a neanderthal and a human? Before dismissing it, think about it, think about the possibilities and what we could represent.
Cheers
Andy
An interesting topic!
Firstly I would ask; is there a third possibility; that there are multiple autism phenotypes? Autism is currently defined pretty much by it's behavioural signs, but different internal experiences might produce the same observable signs. For example; some of us find eye contact hard because it creeps us out; others find it hard because it adds to sensory processing strain; others, because of difficulties with focusing their attention. However, all of these could be labelled as the diagnostic sign "poor eye-contact" (would this even be a diagnostic sign at all in a culture which frowns upon eye-contact? - e.g. Japan.) Similarly with social reciprocation; does the person struggle because of poor theory of mind; because of slow language processing; because of lack of focus; because they have no motivation to?
I read a lot of research papers about autism, and I find that many simply make assumptions about the inner causes of observed behaviour, and only correlate the behaviour itself with outcomes. We could see autism not as a specific condition, but a category of conditions in which the internal model of the world differs from what is typical to a degree which leads to the diagnostic behaviours; but this doesn't imply that the "different internal world", and the sensory, perceptual and cognitive differences which cause it, are comparable from one "sub-type" of autism to the next. That there is a lot of commonality in our difficulties dealing with the non-autistic world may not necessarily imply that we share anything in particular genetically; the very fact that we are different may be more important to outcomes than the exact way in which we are different at a biological level.
The fact that the genetics of autism seems complex is not surprising; there are very few genes which act alone, and very few which code for a single physical or psychological trait. Each gene is just a code for producing certain bio-chemicals, subject to the type of cell, it's location in the body, environmental factors etc. - it's the particular combination of those bio-chemicals, the way that they interact, and where they are found in the body which determine the end result. This is further complicated by the relatively new science of epigenetics, which has shown that heritable changes can happen without the DNA codes themselves being mutated.
Much of our DNA is inert, chemically "turned-off" by chemical markers; but various factors have been shown capable of enabling or disabling these chemical switches, and the changes can be inherited - this is the essence of epigenetics. There are even suggestions that our life experiences can have heritable epigenetic effects due to things like stress hormones changing the state of these switches. In effect, there may be non-autistic people who have a set of genes associated with autism, but who show no effects because those genes are disabled; this might be revealed in subsequent generations due to a chemical exposure which epigenetically enables those genes without having to change the DNA code itself. This has been suggested as a mechanism for the recently reported link between autism and exposure to the pesticide DDT, and implies that the OP's suggestion of auto-immune related autism is not so far fetched. Some of us might, in part, be autistic because ancestors several generations removed were exposed to something environmental which we have never been exposed to ourselves.
Autism being a sign that we are more "Neanderthal" is an interesting idea. I wouldn't go quite as far as that, as I believe that all humans are mongrels to a greater or lesser extent, but it's certainly possible to come up with a mechanism for it. The environmental conditions may well have been very different between the migrations which led to Neanderthal societies and those of later migrations, so there could well have been evolutionary pressures which led to different kinds of perception and cognition being more fit in an evolutionary sense. The traditional definition of a species is that its members can produce viable offspring, but cases where speciation has been observed happening have led biologists to question how well this represents the spread of diversity. There may not be an easy way to decide whether Neanderthals were a separate species, just an outlying variation of our own, or some kind of accidental biological compatibility. They have now been shown archaeologically to have been capable of much the same toolmaking and artwork as our own species when it was still very young, so we may have been much more psychologically and socially similar than the traditional "ogre in a cave" impression of Neanderthals would suggest. Whether African populations, who don't have the Neanderthal component, truly experience less autism is also a very tricky point to establish; differences in economic status, social attitudes and healthcare systems could easily mask the true extent of autism, just as many of us here would not have been thought autistic as little as a generation ago.
I don't think there's much hope of finding specific causes except for a few special cases, as there are so many confounding factors; there will likely just be combinations of risk factors which in most cases would not be totally reliable as markers. However, I don't think we'll get very far along that road until researchers look more behind the social effects of autism into the perceptual and cognitive differences which cause them; we need to know first whether there are different sub-categories of autism, and if so, what they are.