Evolutionary arguments about disease are difficult. Make sure your argument does not explain too much: vitamin >deficiencies are real!
Yes, they are difficult. That is because there are many factors at play in reality. But if his theory was correct, the solution would be so simple that evolution could solve it easily.
In reality, vitmain deficiencies have strong negative consequences, but nothing as drastic as what he proposes.
If vitamin deficiencies really had such an incredibly huge impact there would be a much stronger evolutionary pressure. With such a strong pressure, evolution might have developed vitamin storage organs or even a way for creatures to exchange vitamins to prevent vitamin deficiencies at any cost.
In fact, vitamin deficiencies are rare, unless you do something outlandish like settle and live on crops. The reason humans need so many vitamins in the first place is that we could easily get them, so could easily drop synthetizing them to put more resources in growing brains to outsmart each other. Most animals need fewer vitamines.
I’m not aware of either a similar trade-off, much less a similar change in conditions (disease would have to become rare before agriculture, then common again), with disease.
Do you have a reference for any of that? It sounds reasonable that vitamin deficiencies are the result of farming, but the loss of synthesis to the specific demand of increasing brain size seems like a too specific hypothesis. In particular, almost no primates synthesize C, while almost all mammals do. Britannica lists six vitamins that no vertebrates synthesize (though it includes D, which all land animals synthesize by sunlight). Other than C, I was unable to track down claims about variation across species. Britannica claims that “more highly evolved” animals need more vitamins.
We don’t have much information about disease among hunter-gatherers. Intermediate pastoralists are more accessible. The book Diseases in Human Evolution seems relevant. Chapter 19 lists many historical accounts of vitamin deficiency. Many were not the result not of all farming, but of the wrong grain. Scurvy was seasonal.
I’ve also heard a plausible argument that agriculture results in much less mineral content in the soil. Note that organic agriculture as usually defined isn’t going to solve the problem—the manure from animals eating plants from lower mineral soil doesn’t get the mineral level back up.
Nothing but deliberately putting minerals back (which ones? how much?) or another glacial period is going to change the situation.
I don’t think evolution always compensates for changed conditions—sometimes the pathways aren’t available, sometimes the lucky chance doesn’t happen, and, after all, you don’t have to get back to the previous level of competence—your competitors are operating under the same constrained conditions you are.
It’s good to see skepticism in attributing everything to genetics...
Some legit anthropologists think pre-agricultural humans actually frequently lived into their 70s and 80s, contrary to popular assumptions
I would consider the possibility that changes in lifestyle and/or diet somewhere between 10,000 years ago and the present could have SERIOUSLY affected human health and social organization. Particular culprits I personally find likely are soil-nutrient depletion, the hyper-domestication and consolidation of monocropping corn & wheat, or confounding modern environmental factors introduced by not-fully-understood technologies.
Maybe decreasing infant mortality means more unhealthy babies are being born to become unhealthy adults
Douglas_Knight is essentially right. NancyLebovitz also makes a good point.
The confounding factors are too complex to possibly deal with individually in the present, so we have to have massive experiments using the best available methods to establish correlation in present-day circumstances.
Yes, they are difficult. That is because there are many factors at play in reality. But if his theory was correct, the solution would be so simple that evolution could solve it easily.
In reality, vitmain deficiencies have strong negative consequences, but nothing as drastic as what he proposes.
If vitamin deficiencies really had such an incredibly huge impact there would be a much stronger evolutionary pressure. With such a strong pressure, evolution might have developed vitamin storage organs or even a way for creatures to exchange vitamins to prevent vitamin deficiencies at any cost.
In fact, vitamin deficiencies are rare, unless you do something outlandish like settle and live on crops. The reason humans need so many vitamins in the first place is that we could easily get them, so could easily drop synthetizing them to put more resources in growing brains to outsmart each other. Most animals need fewer vitamines.
I’m not aware of either a similar trade-off, much less a similar change in conditions (disease would have to become rare before agriculture, then common again), with disease.
Do you have a reference for any of that? It sounds reasonable that vitamin deficiencies are the result of farming, but the loss of synthesis to the specific demand of increasing brain size seems like a too specific hypothesis. In particular, almost no primates synthesize C, while almost all mammals do. Britannica lists six vitamins that no vertebrates synthesize (though it includes D, which all land animals synthesize by sunlight). Other than C, I was unable to track down claims about variation across species. Britannica claims that “more highly evolved” animals need more vitamins.
We don’t have much information about disease among hunter-gatherers. Intermediate pastoralists are more accessible. The book Diseases in Human Evolution seems relevant. Chapter 19 lists many historical accounts of vitamin deficiency. Many were not the result not of all farming, but of the wrong grain. Scurvy was seasonal.
I’ve also heard a plausible argument that agriculture results in much less mineral content in the soil. Note that organic agriculture as usually defined isn’t going to solve the problem—the manure from animals eating plants from lower mineral soil doesn’t get the mineral level back up.
Nothing but deliberately putting minerals back (which ones? how much?) or another glacial period is going to change the situation.
I don’t think evolution always compensates for changed conditions—sometimes the pathways aren’t available, sometimes the lucky chance doesn’t happen, and, after all, you don’t have to get back to the previous level of competence—your competitors are operating under the same constrained conditions you are.
It’s good to see skepticism in attributing everything to genetics...
Some legit anthropologists think pre-agricultural humans actually frequently lived into their 70s and 80s, contrary to popular assumptions
I would consider the possibility that changes in lifestyle and/or diet somewhere between 10,000 years ago and the present could have SERIOUSLY affected human health and social organization. Particular culprits I personally find likely are soil-nutrient depletion, the hyper-domestication and consolidation of monocropping corn & wheat, or confounding modern environmental factors introduced by not-fully-understood technologies.
Maybe decreasing infant mortality means more unhealthy babies are being born to become unhealthy adults
Douglas_Knight is essentially right. NancyLebovitz also makes a good point. The confounding factors are too complex to possibly deal with individually in the present, so we have to have massive experiments using the best available methods to establish correlation in present-day circumstances.