I’m pretty sure it’s OK. We’ve already talked the latest round of hype into the ground. Also, this is weirdly entertaining. Or entertainingly weird. Probably both really.
I’ll try to be brief: human change is gradual, on the scale of millions of years; however, the average phenotype, basically how each one of us looks from skin tone to hair type and how hirsute we are, is influenced by our genetic ancestors and can change radically in just a few generations.
Gradual, yes. But nowhere near that gradual. Those who, unlike me, actually know what they’re talking about, are very confident our species isn’t even 0.3 million years old.
Now, in human evolution the main forces for evolutionary change are adaptation to environment - survival (aka fitness) - reproduction; however, modern humans are tricky when compared to other animals because while we can provide in a rather straightforward manner for our survival (feeding and shelter) we are highly variable in our reproductive behaviour (from not reproducing at all to having multiple partners, etc).
But as you point out, we’re not talking about the evolution of a species as a whole, we’re talking about a specific, rare trait that quite likely compromises the ability to find a mate for those who exhibit it.
The species doesn’t need to enter an organised breeding plan to get rid of it. You only need the very few people who have the opportunity to pass along the trait, to stop doing it. And without meaning to impose my tastes on everyone else, I’m reasonably confident most people with the opportunity to have little furball babies, decline.
There’s probably a few who won’t pass up the opportunity. A very few might even be seeking it out specifically. So it’s not likely to vanish in a single generation. But in a world where people as a rule don’t want to have furball babies, it won’t take many generations before the trait is so rare that even those who’d want to pass it on, won’t have the chance. At which point it will be gone. That’s of course assuming the trait is as straightforward as that. I don’t know & I’m afraid I’ll have nightmares if I look it up. But given that assumption it won’t take thousands of generations before the trait is gone. It’s a guess, but 50 sounds way more likely.
The evolution of a species can be very slow, but it doesn’t have to be. Whether it is or not depends greatly on the sizes and relative isolation of groups of the species. The severity of the pressures affecting them is just one collection of factors, and not necessarily the strongest one.
Stuff like horse & dog breeding offer nice examples.
As mentioned, I my understanding of the subject is extremely basic and very limited. So apologies if I just said a bunch of stuff you already know, or know better than. But you really don’t give the impression that you know more about the subject than I do.
