[WildUtah]

Yes. The only way to long run sustainability is central control of population with mandatory birth limits or unlimited expansion of land area to extraterrestrial territory.

Otherwise evolution will always exceed its limits and produce a crash. Malthus explained it all mathematically 200 years ago, even before Darwin documented the mechanisms.

[b_emery]

> The only way to long run sustainability is central control of population with mandatory birth limits

This is demonstrably not true. Look at Japan and western Europe: declining population. Its a function of economic situation (no need for more than 1-3 children) and female reproductive choice. If we give that to the world, the population problem goes away. The mathematics of population dynamics work for animals, roughly, but the assumptions don't hold for humans because of the changes in behavior.

[WildUtah]

There are people, even in Japan, that want a whole mess of children. That preference is heritable. Each generation has more of these people because they're the ones that reproduce.

Eventually those fertile and natal enthusiasts will dominate the population and exponential growth resumes. The current situation is a temporary response to an external shock, specifically to reliable contraception. But Malthusian conditions will return; Darwinism requires it.

[kbutler]

Statistics suggest your view of Darwinism is incorrect.

http://www.infoplease.com/ipa/A0884238.html shows avg household size has been declining since before contraception, and it doesn't look like contraception changed the slope.

[b_emery]

I respectfully disagree. Your assumption about the preference being heritable is questionable.

[wolfgke]

Couldn't it not be a gene but a meme that is inherited, instead?

> Each generation has more of these people because they're the ones that reproduce.

I.e. each generation has more of these people since people who see having children as something positive reproduce and teach these values to their children.

Being a memetic instead of genetic factor would have the advantage that it is easier to "unprogram" it, i.e. by having rules/incentives in the society that discourage reproduction or by education.

[kbutler]

Did you forget the /s tag?

It's pretty well understood that population growth curves are logistical, rather than exponential (e.g., https://www.britannica.com/science/population-growth/images-...)

The appearance of exponential growth is always temporary.

As the population increases, negative feedbacks reduce the population growth rate. Examples of these feedbacks include cost to raise children, reduced dependence on large family for security in old age, etc.

Estimates of the "replacement fertility rate" are about 2.1 per woman in a developed society (higher in less-developed societies). Many first world countries are already below this rate, and without immigration, will have declining populations as their native populations age.

https://en.wikipedia.org/wiki/Sub-replacement_fertility https://en.wikipedia.org/wiki/List_of_sovereign_states_and_d...

Malthus and his disciples have been wrong for 200 years.

Paul Ehrlich in particular, because he used to like giving short-term dates for his predictions, so we could watch them slide by. Then he decided time was different to him than to an "average person".

“How many years do you have to not have the world end” to reach a conclusion that “maybe it didn’t end because that reason was wrong?” -- Steward Brand, former disciple of Ehrlich

[snrplfth]

Well, Paul Ehrlich is an entomologist, so it's not too surprising that he should consider human populations to be essentially automatic, mindless swarms.