[quote=PlazmaStryke]
For genetic disversity, shouldn't It be both?The Chaos of Life would need more to keep things interesting in every species, right?
[/quote]

Heh, yeah, I just thought about "Why not both?". So yeah, my suggestion would be to give pregnancy to all. It'll be the children's choice whether it's painful or not, and how much time it lasts.

And/or just populate the world with more stuff.