Very interesting post. The intertwinement of genetic and cultural evolution is very convincing. Given the point about inertia in large population, is it a common view that in the (relatively) recent past selection may have slowed down in large scale societies?
There are too many confounds to give an answer. In Western societies, cognitive evolution did slow down during the late nineteenth century and even regressed during the twentieth. But the immediate cause was the decline in fertility among middle class couples.
Large societies are fragile. People normally feel loyal to their families and immediate kin and are much less likely to make sacrifices for larger societies. Only Northwest Europeans and East Asians have been able to resolve the "Large Society Problem," and in both cases the solution is precarious.
For instance, low time preference helps make larger societies more stable over time. People are more willing to make sacrifices for the future (short-term pain for long-term gain), but they also postpone fertility too far into the future. Similarly, moral universalism is better than kinship morality for the cohesion of larger societies. But moral universalism can be manipulated by free riders, often cynically so.
Frost, P. (2020). The large society problem in Northwest Europe and East Asia. Advances in Anthropology 10(3): 214-134. https://doi.org/10.4236/aa.2020.103012
Thanks a lot for that explanation and the reference, I will check it out. In regards to fertility, it is one behavioural dimension where we could expect evolution to be fast if you have large differences in a population post demographic transition. I wrote a piece with Jason Collins about it https://www.sciencedirect.com/science/article/pii/S1090513817302799.
I've read discussions of that paper, but this is the first time I've actually read it.
When you talk about genetic influences on fertility, what exactly do you have in mind? You could answer that my question is irrelevant: it is sufficient that genetic influences exist. Fine. But do we know anything about the nature of these influences? Are they mainly proximate? (i.e., acting directly on the physiological processes of fertility). Or are they mainly distal? (i.e., acting on time preference, mate choice, fear of monotony, orientation toward familialism, etc.).
It's clearly an interesting question. As you say, it is orthogonal to that study itself. We took the heredity level indicated by genetic studies and drew the implications for population dynamics. There are plenty of possible underlying mechanisms, like the ones you mention. I don't think the (limited) literature on this question has narrowed down the actual mechanisms.
I think the book to turn to (for laymen) is "The 10.000 year explosion" by Greg Cochran and Henry Harpending from 2009. https://en.wikipedia.org/wiki/The_10,000_Year_Explosion "Starting with their own take on the conventional wisdom that the evolutionary process stopped when modern humans appeared, the authors explain the genetic basis of their view that human evolution is accelerating" -- The authors have a very outspoken blog https://westhunt.wordpress.com/2019/04/ - last post was 2022.
Thank you for the background. And for a fine obituary for a fine scientist. Omnes vulnerant, ultima necat, indeed. - I hope Greg is doing ok - at 70? There are better uses of his time than to blog;, for sure.. Very best regards
I'm wondering what the phenotypic change to vision was the happened after the advent of AMHs, especially since apparently it was the most significant. Does it mean something more general like visiou-spatial ability?
Not so much vision itself as the means to store visual data from different points across time and space.
As modern humans spread into more northern environments, they had to hunt over a larger area (because game animals were fewer per square km. and more migratory). Humans thus had to remember visual landmarks over a greater span of time and space. This need to store large quantities of spatiotemporal data led to an increase in brain size among arctic and subarctic humans. http://evoandproud.blogspot.com/2022/11/recent-evolution-in-human-brain-size.html
Very interesting post. The intertwinement of genetic and cultural evolution is very convincing. Given the point about inertia in large population, is it a common view that in the (relatively) recent past selection may have slowed down in large scale societies?
There are too many confounds to give an answer. In Western societies, cognitive evolution did slow down during the late nineteenth century and even regressed during the twentieth. But the immediate cause was the decline in fertility among middle class couples.
Large societies are fragile. People normally feel loyal to their families and immediate kin and are much less likely to make sacrifices for larger societies. Only Northwest Europeans and East Asians have been able to resolve the "Large Society Problem," and in both cases the solution is precarious.
For instance, low time preference helps make larger societies more stable over time. People are more willing to make sacrifices for the future (short-term pain for long-term gain), but they also postpone fertility too far into the future. Similarly, moral universalism is better than kinship morality for the cohesion of larger societies. But moral universalism can be manipulated by free riders, often cynically so.
Frost, P. (2020). The large society problem in Northwest Europe and East Asia. Advances in Anthropology 10(3): 214-134. https://doi.org/10.4236/aa.2020.103012
Thanks a lot for that explanation and the reference, I will check it out. In regards to fertility, it is one behavioural dimension where we could expect evolution to be fast if you have large differences in a population post demographic transition. I wrote a piece with Jason Collins about it https://www.sciencedirect.com/science/article/pii/S1090513817302799.
I've read discussions of that paper, but this is the first time I've actually read it.
When you talk about genetic influences on fertility, what exactly do you have in mind? You could answer that my question is irrelevant: it is sufficient that genetic influences exist. Fine. But do we know anything about the nature of these influences? Are they mainly proximate? (i.e., acting directly on the physiological processes of fertility). Or are they mainly distal? (i.e., acting on time preference, mate choice, fear of monotony, orientation toward familialism, etc.).
It's clearly an interesting question. As you say, it is orthogonal to that study itself. We took the heredity level indicated by genetic studies and drew the implications for population dynamics. There are plenty of possible underlying mechanisms, like the ones you mention. I don't think the (limited) literature on this question has narrowed down the actual mechanisms.
I think the book to turn to (for laymen) is "The 10.000 year explosion" by Greg Cochran and Henry Harpending from 2009. https://en.wikipedia.org/wiki/The_10,000_Year_Explosion "Starting with their own take on the conventional wisdom that the evolutionary process stopped when modern humans appeared, the authors explain the genetic basis of their view that human evolution is accelerating" -- The authors have a very outspoken blog https://westhunt.wordpress.com/2019/04/ - last post was 2022.
Mark,
Greg and Henry were co-authors of the 2007 study by John Hawks. They wrote that book as a way to popularize their findings. Henry died 7 years ago:
https://www.unz.com/pfrost/farewell-to-henry/
Thank you for the background. And for a fine obituary for a fine scientist. Omnes vulnerant, ultima necat, indeed. - I hope Greg is doing ok - at 70? There are better uses of his time than to blog;, for sure.. Very best regards
I'm wondering what the phenotypic change to vision was the happened after the advent of AMHs, especially since apparently it was the most significant. Does it mean something more general like visiou-spatial ability?
Not so much vision itself as the means to store visual data from different points across time and space.
As modern humans spread into more northern environments, they had to hunt over a larger area (because game animals were fewer per square km. and more migratory). Humans thus had to remember visual landmarks over a greater span of time and space. This need to store large quantities of spatiotemporal data led to an increase in brain size among arctic and subarctic humans. http://evoandproud.blogspot.com/2022/11/recent-evolution-in-human-brain-size.html