Classic Maya remains are going to be quite interesting. I wonder what the genotypic profile of those Mayas will look like. They developed a fully fleshed-out writing system and appear to have had an advanced astronomical tradition. The most direct indication of high intelligence is that they sustained a very high population density in the Maya lowlands (possibly as many as 16 million people at their peak!). Of course, while they hold no candle to the Ancient Greeks, it should also be taken into account that they achieved all of this in a far less dynamic environment, with limited external influences or predecessors beyond other surrounding Mesoamerican cultures. What might their solution to the large society problem have looked like? Their decline seems particularly severe as well, with extreme depopulation in the Maya lowlands (up to 90% in some areas, apparently) by the end of the Classic era and a reduction in the complexity of their writing system.
Ancient DNA is poorly preserved in tropical regions, like the Yucatan, see this review article:
Mesoamerican ancient DNA (aDNA) research has mainly focused on the study of mitochondrial DNA in the Basin of Mexico and the Yucatán Peninsula and its nearby territories, particularly during the Postclassic period (900–1519 CE). Despite limitations associated with the poor preservation of samples in tropical areas, recent methodological improvements pave the way for a deeper analysis of Mesoamerica.
Razib's latest article suggested cognitive ability declined with Steppe invasions in Europe and neolithic farmers haf higher cognitive profiles than later Euroeans? Does that match the evidence?
I read through it quickly but I didn't see anything on cognitive ability. Mean cognitive ability was probably a bit higher at the end of the Neolithic than at the end of the Imperial Era.
Quote: "We adapt not only to natural habitats but also to culture. As the latter became more important, human evolution speeded up to cope with new demands on cognitive ability."
I don't doubt that evolution speeded up over the last ten thousand years, but I do question whether, for most humans, the cognitive demands increased compared to what they were in hunting and gathering days. (Full disclosure: I haven't read the article yet so may change my mind.)
Addendum: "Finally, future studies ought to control genomic data for socioeconomic status (SES). Otherwise, there may be sampling bias. " I think this might be the source of the problem: peasant life is not nearly as cognitively demanding as life in hunter/gatherer societies. For artisans and those further up the status hierarchy in post-Neolithic societies that may not be the case. IQ's could rise in part due to differential survival rates of the better off (Gregory Clark's argument) and in part due to the higher cognitive demands on those further up the class structure in the first place.
Further full disclosure: I'm a complete amateur, and 83 to boot. Just like the subject.
Mean cognitive ability remained unchanged throughout the period of hunting and gathering. It then rose progressively after the transition to farming. It looks like there was an increasing demand for cognitive ability.
In all fairness, I should stress the following points:
- Sample sizes of DNA are small for the pre-farming period (because population size was small), so some degree of caution is needed when interpreting the data.
- There may have been differences among hunter-gatherers in cognitive ability. In particular, there was probably a north-south cline, with higher cognitive ability at higher latitudes.
- The initial surge of cognitive ability in the early Neolithic (see Akbari et al) may be due to population replacement of early farmers through absorption of indigenous hunter-gatherers.
3. Christianity (increase in fertility among elite individuals through increase in marital stability and discouragement of non-procreative sexual relationships)
Not at all convincing, for one very simple reason each generation of Western Europeans for at least the last 50 years have been increasingly stupid and useless driven by the increasing shallowness of the culture.
Any theory which extrapolates mental and emotional characteristics based solely on genetics is at best a very partial view and takes no account of cultural influences which are at least as important to human development , if not more so ( and there is a lot of evidence for the latter).
This evidence doesn’t exist at cellular level , unlikely these nerds would get their vision above the level of their electron microscopes though, as they completely lack contextual intelligence.
Classic Maya remains are going to be quite interesting. I wonder what the genotypic profile of those Mayas will look like. They developed a fully fleshed-out writing system and appear to have had an advanced astronomical tradition. The most direct indication of high intelligence is that they sustained a very high population density in the Maya lowlands (possibly as many as 16 million people at their peak!). Of course, while they hold no candle to the Ancient Greeks, it should also be taken into account that they achieved all of this in a far less dynamic environment, with limited external influences or predecessors beyond other surrounding Mesoamerican cultures. What might their solution to the large society problem have looked like? Their decline seems particularly severe as well, with extreme depopulation in the Maya lowlands (up to 90% in some areas, apparently) by the end of the Classic era and a reduction in the complexity of their writing system.
Ancient DNA is poorly preserved in tropical regions, like the Yucatan, see this review article:
Mesoamerican ancient DNA (aDNA) research has mainly focused on the study of mitochondrial DNA in the Basin of Mexico and the Yucatán Peninsula and its nearby territories, particularly during the Postclassic period (900–1519 CE). Despite limitations associated with the poor preservation of samples in tropical areas, recent methodological improvements pave the way for a deeper analysis of Mesoamerica.
https://doi.org/10.3390/genes11111346
I certainly would like to see a study of cognitive evolution among the Maya, as well as the civilizations of the Andes and central Mexico.
potential typos -
>human evolution speeded up to cope
>the Imperial Era (27-300 BCE), Late Antiquity (300-700 BCE), and medieval/early modern times (700-1800).
Thanks! The dates have been fixed. What would you like to change in your first point?
Razib's latest article suggested cognitive ability declined with Steppe invasions in Europe and neolithic farmers haf higher cognitive profiles than later Euroeans? Does that match the evidence?
Are you referring to this post? https://www.razibkhan.com/p/two-steppes-forward-one-step-back
I read through it quickly but I didn't see anything on cognitive ability. Mean cognitive ability was probably a bit higher at the end of the Neolithic than at the end of the Imperial Era.
Quote: "We adapt not only to natural habitats but also to culture. As the latter became more important, human evolution speeded up to cope with new demands on cognitive ability."
I don't doubt that evolution speeded up over the last ten thousand years, but I do question whether, for most humans, the cognitive demands increased compared to what they were in hunting and gathering days. (Full disclosure: I haven't read the article yet so may change my mind.)
Addendum: "Finally, future studies ought to control genomic data for socioeconomic status (SES). Otherwise, there may be sampling bias. " I think this might be the source of the problem: peasant life is not nearly as cognitively demanding as life in hunter/gatherer societies. For artisans and those further up the status hierarchy in post-Neolithic societies that may not be the case. IQ's could rise in part due to differential survival rates of the better off (Gregory Clark's argument) and in part due to the higher cognitive demands on those further up the class structure in the first place.
Further full disclosure: I'm a complete amateur, and 83 to boot. Just like the subject.
Mean cognitive ability remained unchanged throughout the period of hunting and gathering. It then rose progressively after the transition to farming. It looks like there was an increasing demand for cognitive ability.
In all fairness, I should stress the following points:
- Sample sizes of DNA are small for the pre-farming period (because population size was small), so some degree of caution is needed when interpreting the data.
- There may have been differences among hunter-gatherers in cognitive ability. In particular, there was probably a north-south cline, with higher cognitive ability at higher latitudes.
- The initial surge of cognitive ability in the early Neolithic (see Akbari et al) may be due to population replacement of early farmers through absorption of indigenous hunter-gatherers.
Thanks.
Very useful overview of the literature.
Thanks for outlining the periods of rapid increases in cognitive ability. One can only wonder what initiated these periods.
1. Farming
2. Increase in social complexity
3. Christianity (increase in fertility among elite individuals through increase in marital stability and discouragement of non-procreative sexual relationships)
Not at all convincing, for one very simple reason each generation of Western Europeans for at least the last 50 years have been increasingly stupid and useless driven by the increasing shallowness of the culture.
Any theory which extrapolates mental and emotional characteristics based solely on genetics is at best a very partial view and takes no account of cultural influences which are at least as important to human development , if not more so ( and there is a lot of evidence for the latter).
This evidence doesn’t exist at cellular level , unlikely these nerds would get their vision above the level of their electron microscopes though, as they completely lack contextual intelligence.