I'd recommend version .97 as it seems more stable.
Version .95 worked fine with vagrant pregnancy on, but it began to crash with multiple errors as soon as I set general pregnancy to "off" (to get offsprings instantly).
When I tried the same with v.0.97, there were no crashes.
Anyways, the game at this stage finally works as a real sandbox. Moreover, if you feel lazy enough, you can have it running in an "automated mode" (with vagrants randomly impregnating each other), while you enjoy watching the outcome.