After watching this video I am left with this question.

The video ultimately claims that humans will not disappear, but doesn’t do a great job explaining why.

Correct me if I’m wrong, but for the (or a) population to be and remain stable, the total fertility rate needs to be equal to the global replacement rate (which recently was 2.3).

And since the total average fertility rate appears to be currently at this 2.3, any drop in the fertility rate in place A would have to be compensated with a rise in the fertility rate in place B (assuming that, at some point, we would like to stop population decline)?

I guess one way for a population to remain stable, while women are having fewer than 2.3 children, would be to have fewer men? If a population has 100 women and 10 men, each woman would only have to have on average (a bit more than) 1.1 child? (Which would of course also require a collective form of prenatal sex selection.)

I realize that would be bonkers and unethical. Just wondering out loud.

  • @saltesc
    33•5 months ago

    Mathematically? Obviously, yes.

    Socially? Would never happen. Imagine our population is just stock. It goes up and down depending on how good things look. At some point, it cannot continue as it’s not financially feasible. But when it drops back down into realistic numbers, balance goes up again.

    You can see this behaviour in the generations (Z, Y, X, Boomer, Pre-war, etc.) These generation changes are marked by a tipping point of birthrate increasing or decreasing in a nation—typically globally, which is why we all tend to agree on the start/end of generational eras within 3–5 years.

    • FaceDeer
      5•5 months ago

      Not to mention that technology is continuing to advance in new and unexpected ways.

      We’re getting close to artificial womb technology, for example. There are already artificial wombs that are being experimented with as a way to save extremely premature babies that wouldn’t survive in a conventional incubator, for example.

      Commodity humanoid robots are also in development, and AI has taken surprisingly rapid leaps in development over the past two years.

      I could see a possibility where in a couple of decades a human baby could be born from an artificial womb and raised to adulthood entirely by machines, if we really really needed to for some reason. Embryo space colonization is the usual example given, but it could also potentially work as a way to counter population decline due to people simply not wanting to do their own birthing and child-rearing.