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
question 1:
Handi-andis said:Does there have to be a single root cause for autism or could there be more than one mechanism?
question 2:
Handi-andis said:Could there actually be two "human" species on the planet?
Well this seems a learned thread, or at least one looking at expert research. I have to admit I will often link to a paper without having studied it in detail as I don't really have the energy or specialist research literacy.
Graham's Nature link above, for example, I just skimmed enough for me to assimilate the idea of a 'Neanderthal genetic load', and to wonder if phrenology will return in trying to find links to personality. Here's something by G. Bradley Schaefer (from a lower-quality journal) that I found via Wikipedia, asking
is there an “ASD face”?
That paper is also relevant to question 1. I think despite some enthusiasms about pet theories and overarching frameworks, almost all researchers will admit there are many different things contributing to 'autism'.
Current understanding recognizes autism as having a strong genetic basis with a complex inheritance pattern. Strong genetic factors are involved. As with all human medical conditions, there is environmental modulation. There is clear etiologic and genetic heterogeneity. Literally hundreds of “autism genes” have been identified. Thus, from an etiologic standpoint, it would be better stated “the autisms” rather than “autism”. This understanding will be critical as the science of autism therapies moves forward. Using targeted therapies for specific identified causes of autism holds the promise of improved outcomes and reduced adverse events.
On the subject of 'environmental modulation', Mandy & Lai provide a good and comprehensive review of 'The role of the environment in the developmental psychopathology of autism spectrum condition', distinguishing environmental factors that may add to, or potentiate/multiply risks, and those that may just be associated with autism for some other reason (see mention of taking SSRIs in pregnancy).
Trogluddite mentions epigenetics, and one of the strongest links mentioned by Mandy & Lai is the link between lack of folic acid in pregnancy and 'autistic disorder' (that is, classic Kanner syndrome), and folic acid seems necessary for inter-generational epigenetic changes to happen properly.
If you take autism as meaning differences or difficulties in engaging socially, then it's hard to avoid the facts that (a) engaging socially is an extremely complex process requiring all kinds of different human faculties, cognitive, emotional and other; (b) society is also extremely complex; (c) the interaction of these two is likely to be complex as well. Any number of things could 'go wrong'. This is why I think the notion of a 'syndrome' is misleading. It's also important to realise that some gene variant might be beneficial in one environment, but in other circumstances contribute to 'autism'.
I answer question 2 with 'no'. There were Denisovians and hobbit men (H floresiensis) and all the rest interbreeding. However, I don't even think autistic people and typical people are different tribes let alone species (as in 'finding your tribe' and the title of Neurotribes). I think autistic people are spread throughout every other way H sapiens divides and tend to crop up randomly, and you can also think of autism in at least two other ways: (a) communities may well benefit from having one or more individuals who think differently, are interested in things and animals, or find new knowledge, despite being on the outskirts of that community; (b) some communities stratify in terms of social (not economic) success and some people, based on personal characteristics and luck, are going to find things much harder going than others.
I've mentioned spending time at Autscape and other autistic-dominated events, and actually they're noticeably non-tribal and accepting diversity. There are people who find shared interests, but communication between two autistic people can be fraught with differing needs. More to the point, although autistic–autistic conversation is in many ways more relaxed and interesting and probably functional than autistic–typical communication, there can be long periods of (not necessarily uncomfortable) silence, which does suggest to me that it's not as rich an interaction as between two 'typicals', however defined. Graham mentioned being in a room of people wanting to talk about video games, when presumably he'd prefer to discuss (or read) Marcel Proust.
On the other hand I'm not ruling out the Neanderthal theory as something associated with a particular direction contributing to autism instead of its diversity. That is, all kinds of difference may be seen as autistic or 'weird', but there may be a functional variation in a particular direction, such as hypersensitivity, detailed attention, connection to animals and physical processes more than social relations, when occurring together approaching a 'syndrome'. The guy who made the 'Aspie quiz' has speculated at length on the Neanderthal theory of autism (I don't understand all the statistical conclusions from his testing). Jared Diamond believed Neanderthals didn't have spoken language, and that might fit in again (not forgetting that some autistic people are very verbose). One implication this has for me is that if the divergence is traced to at most 1.8 million years ago, and the assimilation of Neanderthals about 35,000 years ago in particular explains some common traits, then relatively well-funded research accepting genetic analogues for autism in distantly-related mammals like mice seems even less likely to be useful.