It is not entirely without merit to say that religious folks that encourage large families like the Amish, Catholics and Mormons will dominate in the distant future. Hell, I have 45 first cousins (on one side) and they on average have 3+ kids so it might just be my extended family :)
I can't help but wonder if large families also beget religion just as religion begets large families.
Now I personally think every religion I've encountered is ridiculous fiction (no offence, just my opinion), but I will admit that there can be some pretty significant advantages in a community. Raising a ton of kids is probably just easier in a close community of similar minded families (a.k.a. the local church/temple/mosque). It's almost like it's intentionally engineered to be this way.
Religion is subject to natural selection just like anything else. Religions which produce more offspring that stay in the religion will always win out over the ones that don't.
> So long as the children survive to give birth to more children
Big if. In a true famine, the poor usually die first.
> Evolution doesn't care for the comfort of anyone.
Evolution cares about sexual desireability and fitness. Rich people usually have more.
In nature we see these two strategies as well. Some species try and have as many babies as possible, where others have fewer but concentrate resources to make sure the few are more likely to survive. Neither strategy is optimal in all situations.