4 ms·

If health has no effect on conception success, I don't see any reason to be worried about declining health. I agree that in-vitro and artificial insemination c

If health has no effect on conception success, I don't see any reason to be worried about declining health. I agree that in-vitro and artificial insemination could remove an important feedback mechanism for sperm evolution, and that would be a cause for worry.

Dalewyn 4y ago
My understanding is that it is starting to (presumably anyway) have an effect on conception, because a sperm that can't move is a sperm that can't fertilize an egg, and there aren't competing superior sperm to make up for the shortfall. Which by itself is fine, really. Sperm that fails to reach an egg means the genes that made that sperm do not "deserve" to reproduce. However, if people want to make a fuss over low birth rates, and this is one factor behind it, it's going to get attention.