Comment by throwuxiytayq
2 days ago
The main problem is that evolution is just not a thing at our modern civilizational time scale.
And I don’t see any problems with late-life reproduction, assuming we can make it reliable and healthy. If anything, some countries desperately need it.
From my reading this is wrong in principle.
Evolution is really slow on average, but locally it moves quite quickly and probably explains the large variation between members of a species.
Add strong selective pressure to that high local speed and you can change a good part of the genotype within a couple of generations. See: animal husbandry. You can breed a new race of dog within 5-10 generations.
Ethics aside we could probably breed people who can sniff out Alzheimer's in less than 250 years.
Our current late reproduction style will very likely influence future generations health at older ages.
It's probably a wash. Sure people are reproducing later, but it's also more likely that they have recieved some major medical intervention to allow them to make it to that stage. For example, it could be stuff like freezing eggs before starting chemo.
That in of itself is an external selection pressure though, having enough fit to gather resources to delay reproduction.
> in less than 250 years
I don't dispute any of your points in general. But at the same time, it brings a nostalgic smile to my face to envision starting a 250-year project in 2025.
Someone needs to remain alive to provide, protect and raise the kids.
Evolution is still a thing at relatively short time periods.
Icelanders are a well-studied population when it comes to genetics. Frequency of some traits meaningfully changed among them in last 100 years.
Source: this book: https://www.amazon.de/dp/0198821263?ref_=pe_109184651_110380...
Also the moths that "changed" from white to black during and because of the industrial revolution. That was quick, and to me, the best example of how it all works.