Well, my high school biology textbook is a resource. If you must, you may ask my Biology teachers. Actually, please don't ask my bio teachers. They'd think that is weird.
It's a funny thing how my biology textbook doesn't even mention Autism. Not in it's evolution chapter, not in it's genetics chapter. Not in any chapter at all, basically. It's almost as if scientists know that Autism isn't an evolution.
Of course your biology textbook doesn't mention autism. I very much doubt there are many high-school textbooks that do. Autism is a subtle variation in the human genome that affects behaviour - a "phenotype" and therefore a bit beyond the scope of such a book. Neither it is a subject that would normally be discussed in an evolutionary context which is the point of the article.
The idea discussed in the article is that autism is not "the next step in evolution" as some people like to speculate. The reason being that evolution does not work in the simplistic way those people suggest. Evolution has no direction, no drive for perfection - it's a process of survival in an ever changing world. Those best adapted to the environment of the time survive and reproduce whilst the weakest perish. It takes hundreds of generations for even tiny mutations to make an impact on evolution which in human terms means tens of thousands of years. That's why Drosophila have been so important in biological study, because they reproduce so quickly we can observe the pace of change over hundreds of generations.
Autism has been a variation in the human genome since the first modern Homo Sapiens walked this Earth approximately 315,000 years ago. That it still exists today demonstrates it has some value to our survival as a species or we all would have died out by now.
How about we talk about the differences between wolves and beagles? That difference has taken about 10,000 years to occur, since dogs were first domesticated. That's not evolution. That's selective breeding. In human terms you would call it "eugenics". Humans specifically bred wolves with similar traits together to propagate those traits and exaggerate them over time - often incestuously - inseminating mothers with the gametes of their sons. Since most wolves and dogs achieve sexual maturity at about 3 years (compared to 13/14 average for humans) that means there have been approximately 3,300 generations of dog/wolves in that time, all the while being manipulated by their human owners/breeders. Domestic dogs, of every breed, are not the result of evolution, they are a human creation. It's the most primitive form of genetic mutation and is exactly the same principle the Nazis wished to apply to human biology. And it still goes on. Look at all these new breeds that are becoming popular - cockerpoos, labradoodles and the like.
The only way that Autism COULD become the next step in evolution would be to sterilise everyone who is NOT on the spectrum and only allow autistic people to bear offspring. Considering we number somewhere between 1/100 to 1/30 of the current population, that would cause a massive reduction in our population and therefore our viability as a species, not to mention being unspeakably evil.
https://www.amazon.co.uk/Selfish-Gene-Anniversary-Landmark-Science/dp/0198788606
https://www.amazon.co.uk/Blind-Watchmaker-Cover-image-differ/dp/0141026162
https://www.amazon.co.uk/Evolution-Beginners-Guide-Guides/dp/1851683712
https://www.amazon.co.uk/Genetics-Beginners-Guide-Guides/dp/1851683046