[nudq]

> You do not understand evolution

Probably.

But although it is almost tautological that fertility is heritable, it doesn't follow that the first world infertility trend will reverse.

If whatever is causing first world infertility (1) actually profits from our infertility and (2) is some kind of evolving entity itself, we could find ourselves in an evolutionary arms race, and lose.

[dTal]

An insightful point. The tacit assumption here is that your "whatever" is some sort of meme, yes? But memes are also strongly heritable. So far, in all of human history, memes which promote celibacy and childlessness have a tendency to die out.