Interesting, thanks.

> That is happening right now. The Y chromosome used to be bigger and is shrinking and will be gone in a few million years.

Can you really extrapolate that it will disappear altogether from the fact that it's shrinking? There's no evolutionary reason that's obvious to me why the Y chromosome needs to be particularly large, but there is an evolutionary reason to have one at all. It's certainly true that there are alternative possibilities, but the probability of losing SRY at a population level is still significantly lower than the probability of losing some other random gene that isn't expressed. Unless there's an established mechanism that means the Y chromosome has to keep shrinking?