The real reason why the righties are shouting Abortion is killing & its supporters are murderers:

[Ampersand Unicode]

76. There's an evolutionary reason?

...for mental illness, substance abuse, and genetic abnormalities like Down syndrome and autism?

They may have been some advantage 10,000 years ago. I've heard this about ADHD being a trait of hunters who had to look in multiple directions and multitask out in the killing fields; that what we consider "schizophrenic delusions" now were actually the visions of tribal shamans, and what we call autism was also a trait of secluded monks who didn't socialize very often and were more in tune with their "inner world." Dyslexia, I've heard, is only a disadvantage because we force people to read left-to-right scripts (this I doubt, because it's more than just reading the wrong direction or transposing letters). I don't know what advantage synesthetes had 10,000 years ago besides maybe also being thought of as having some sort of mystical gift. Down syndrome children were probably sacrificed 10,000 years ago, although maybe that wasn't the case because aren't most cases born to mothers over 40, and back then most people didn't even live that long? Plus, weren't "women" becoming mothers right from about the time they hit puberty? So maybe Down syndrome didn't even exist 10,000 years ago because of conditions that didn't exist then either.

Regardless, since we're not an agricultural nomadic hunter-gatherer society that ascribes high rank to fortune tellers, mead drinkers, mushroom-eaters, and people who have "visions" and talk to imaginary beings that no one else can perceive, why haven't those conditions or tendencies gone away if they're now considered detrimental rather than positive adaptations? The answer is because people who have those DNA markers and traits still continue to reproduce. And also because we have modern medicines that prevent nature from taking its course and weeding out those with congenital heart ailments, and diabetes, and childhood cancers, and other maladies that would have knocked you or your child dead once upon a time. We're probably seeing a negative trade-off in that we're allowing defective people to reproduce whom nature would have prevented from doing so otherwise, and creating new mutations and epidemics of illnesses that, if we had let "nature run its course," probably wouldn't even exist today.

The only solution I guess, if you want to let the nutters continue breeding (and create more nutters such as myself), is to give the born nutters carte blanche to do themselves in if they want to. I'm going OT here, but AFAIC just allowing abortion doesn't go far enough. I'm not a believer in the special-snowflake stuff that everyone has "gifts to give." I know I'm a nutter; my parents shouldn't have had me, but they did, and now I have to find a way to mitigate the circumstances before I become a burden upon society. Especially now that we've got fascists in both houses of Congress who are going to make circumstances even more of a living hell for people who don't "fit in."

I still am a believer in eugenics simply because nature didn't weed me out. And I believe that a "snip" of prevention is worth a lot of cure in terms of averting needless suffering.