Paleofantasy Flashcards
Commentary on the use of modern hunter-gatherers as windows into life before civilization
This classification is incorrect. All human groups have been evolving genetically and socially for the same period of time. We still can learn something from them, but the extent is very limited.
Paleo-diet/’Greatest Mistake In the History of Mankind’ argument
Touted by Jared Diamond and paleo-diet proponents like Loren Cordian:
Adopting agriculture has been a net detriment for humanity due to increased incidence of disease, lack of exercise, and lack of variety in diet.
In Jared Diamond’s words: “With agriculture came the gross social and sexual inequality, the disease and despotism, that curse our existence.”
Spencer Wells takes it farther: “Ultimately, nearly every single major disease affecting modern human populations- whether bacterial, viral, parasitic, or noncommunicable- has its roots in the mismatch between our biology and the world we have created since the advent of agriculture.”
Three types of agriculture
- Horticulture: Relatively unmodified crops are rown and cultivated with simple tools. May be nomadic. May “slash and burn” areas they cultivate, leaving them in-between growing periods.
- Pastoralism: Domesticated herds of animals that feed on natural pasture rather than on food provided by their keepers are. May be somewhat nomadic.
- Intensive agriculture: Fields are more permanent than those used by horticulturalists. Utilizes fertilizer to farm one field indefinitely rather than needing to slash and burn. Crops may be raised in excess for trade, meaning people may live in larger groups and dedicate time to more activities than sustenance. Also provides opportunity for social stratification.
Myths about the Neanderthal Diet
Neanderthals and other early humans ground grains into flour and cooked them. They were not simply restricted to a meat and fruit diet. And the fruit and vegetables they were eating is not the fruit we eat today, which has been changed drastically by domestication.
Importance of Experience to Hunter-Gatherer Output
From what we know from modern hunter-gatherers, production of food from hunting and gathering is a skill that takes decades to master, with lifetime hunter-gatherers not peaking in output until their mid-30’s or 40’s.
Human Evolution in Response to Agriculture
Jared Diamond argues in his essay that, when comparing the centuries straddling the invention of agricultural techniques, the post-agriculture skeletons were shorter and displayed more signs of malnutrition in enamel than the pre-agriculture skeletons. While this is true, this trend only lasted for ~6,000 years and by 4,000 years ago these signs of increased rates of malnutrition disappeared entirely from the archaeological record.
Geoffrey West angle
With the population boom that came from agriculture (from ~1-5 million worldwide pre-agriculture to a few hundred million after the establishment of agriculture), many things scaled superlinearly. This includes disease, but also innovation and evolution (more genes, more mutations, more fodder for natural selection- bigger populations can evolve faster).
‘Unintended consequences of agriculture’
All consequences of evolution are unintended consequences. To say this is to misunderstand evolution. Clearly, agriculture has out-competed hunter-gatherer techniques on a Darwinian level.
Environment of Evolutionary Adaptedness
Coined by psychologist John Bowlby in the late 1960’s. The idea is that natural selection is too slow to catch up to our new environments and that we must consider what we have been adapted for.
This argument has a few major problems:
- Natural selection is much faster than suggested here, especially given human population size. Natural selection may act in ~10 or less generations if the pressure is strong enough.
- The stone-age man bears no greater evolutionary significance to us that to any other of our evolutionary ancestors – the question is not what our genes WERE, it is what are genes ARE. It is more important to look specifically at TODAY’s genetics.
- The number of genes which differ is not as important as WHICH genes differ and HOW they differ. Even though most human genes have not changed since stone-age times, the ones that have tell a clear story: lactase persistence, FOXP2, etc.
Adaptively Relevant Environment
Suggested alternative to the EEA.
A set of environmental features, such as the amount of rainfall or abundance of snakes, that is important to a trait, such as having a fear of reptiles.
As part of his critique of the EEA, Irons, who invented this concept, notes the difficulty of pinning down the precise environment in which any adaptation occurred, since we have many ancestors across many environments almost all of whom were migratory and lived across vast migration paths including many climates.
Pleistocentrism
False belief that all human psychological adaptations are tightly tied to the conditions of Pleistocene foraging societies.
Calcium Assimilation Hypothesis
Proposes that lactose tolerance is advantageous at high latitudes, where sunlight can be scarce and hence vitamin D levels low. Drinking of milk enabled by lactase persistence allows more efficient lifetime uptake of calcium, making up for the vitamin D deficiency.
Supplementary Nutrition Hypothesis
Proposes that lactose tolerance was beneficial for pastoralists who could gain consistent nutrition from herds without sacrificing animals.
Uncontaminated Fluid Hypothesis
Proposes that lactose tolerance was beneficial since milk is a source of uncontaminated water, which was once extremely scarce, especially in desert environments.
Proposed Relationship Between Malaria and Lactase Persistence
Those who do not drink milk in Africa often suffer from low riboflavin (vitamin B2) levels, especially if they are otherwise poorly nourished. The Plasmodium parasite that causes malaria does not grow very quickly in cells which have low stores of B2, and thus people without lactase persistence may be somewhat protected from malaria.
