
If were talking evolution, its actually interesting. The first organisms likely reproduced asexually, so you COULD consider that “jacking off”, as sex hadnt really been invented yet LOL. Sex became advantageous as it diversified the gene pool and allowed the sexes to focus more on producing sperm or eggs (instead of both, thats pretty taxing)
I think it depends on if asexual reproduction counts as “jerkin it” or not. Humans are one of few creatures that have sex solely for pleasure. Assuming asexual reproduction is NOT jerking it, from an evolutionary standpoint it is more likely our early ancestors would not derive sexual pleasure until later on, resulting in sex only being for reproductive purposes, so jerkin it wouldn’t even be a thought