I'm actually glad to be getting a lot of push-back on this idea.

Old men like me can afford to be cynical, but I'm glad the next generation has enough idealists that they reject the dark future I'm predicting.

Still, I'm forced to reply.

> The vast majority of people are already not harnessing more and more resources in order to reproduce more.

Considering that every other species larger than a rat is being driven into extinction, largely because we are converting their habitats into farms or strip malls, I don't see evidence that we've learned not to consume more and more.

Sure, over the next hundred years our population will stabilize, but as the great scientist Jeff Goldblum said, "Life...ah...finds a way!"

If you want to know how humans will evolve you have to ask, which genes will spread? Obviously, genes for raw strength aren't useful--that's what machines are for. What about genes for intelligence? Do the smartest people have the most kids? No, which means those genes won't necessarily dominate.

In nature, every species is constrained either by food availability or predators or both. If two rabbits have four baby rabbits, and those four have eight baby rabbits, then why aren't there trillions of rabbits now? Obviously, it's because eventually they run out of food or get eaten by coyotes.

But a technological species like us has no predators, and we can continue to make more food by cutting down forests (where other species live) and turn them into farms.

The only limit we have right now is that we don't want to have too many kids. Unlike every other species, we can (mostly) control our reproduction, and we sometimes choose to have fewer children so that we can have a more luxurious life.

Of course, the desire to have children varies across individuals. We all know some people who want to have more kids and some who don't want any. It is likely, of course, that this innate desire is partly or mostly heritable.

Over long enough time-scales--maybe a thousand generations or 25,000 years--the genes of people who want to have kids will dominate. By then, of course, we will have run out of forests to cut down, so we'll have to start colonizing the oceans and other planets.

But like I said, I'm just a cynical old man.

You might look into the Norway rat experiments done by Calhoun and the idea of a behavioral sink. The essence of your hypothesis was disproven, in rats, likely before you were born.

It seems your idea of the primacy of the forces of evolution, especially when this view is overextended and when competing forces are oversimplified or excluded, produces this dystopian view.

Reproduction does not continue no matter what. The genes of people who want to have kids have been shown to be overwhelmed within social mammals, purely by social forces.

Humans are unique in that they can escape the behavioral sink. It is your simple extrapolation of the theoretical animal limits that produces projected doom. But that extrapolation does not even hold in animals.