Paleofantasy [Marlene Zuk]

Goodreads link.

Start Date: 27 November 2019

Finish Date: 6 December 2019

Source: Brooklyn Public Library

Notes:

  • This was vastly entertaining. I love a good debunking, even if the idea being debunked was fringe to begin with.
  • I think I found out about Paleofantasy in Angela Saini’s Inferior. More on that later. For now, here are the chapter-by-chapter notes.

Chapter 01: Cavemen in Condos

  • I learned that lower back pain is a consequence of the shift to walking upright
  • ‘Hunting makes sharing necessary and sharing makes hunting necessary’ reminds me of the German Left party’s campaign slogan for higher taxes: ‘Teilen macht spaß!’ Not that there is a clear connection – just two pithy sayings centred around the word ‘share’.
  • The more serious point here is that sharing food could have been the evolutionary trigger for the social structure of human beings.
  • The ability to run begins with Homo ergaster, and it’s possible that running made hunting possible, which led to protein rich food, which led to the development of brains, which led to tool making, which led to Homo sapiens. So Doctor Who’s motif of running, brought about by low budgets, may actually speak to something very deep about the human condition.
  • But by that logic, Bhaag Bhaag D K Bose is also on to something.
  • And because there must be a Pratchett quote: “For now, gloriously uncomplicated and wonderfully clean, and hopefully with never an end, under a clear sky, in a world untarnished… there was only the chase.”
  • The chapter issues a warning that hunter-gatherer groups are not ‘pristine’, and have been interacting with settled groups for ages.
  • Furthermore, hunter-gatherers should be seen as models of small scale societies, not models of prehistoric or pre-evolutionary societies.
  • Ozzy Osbourne did a DNA test, and then claimed that his ability to go through so much alcohol is because he has Neanderthal DNA. Legend.

Chapter 02: Are We Stuck?

  • I have totally forgotten most of Guns, Germs, and Steel – it was new to me that Diamond was anti-agriculture.
  • ‘Hunting gathering takes less time per calorie of food than agriculture’ ignores the time investment required in learning how to become an efficient hunter or gatherer.
  • Yes, disease and malnutrition made the first humans to take up agriculture shorter than their hunter-gatherer ancestors, but the agriculturalists / pastoralists made up the gap within a thousand years.
  • Settlement leads to larger populations, which means a larger absolute number of mutations in genes, which accelerates natural selection and evolution.
  • I learnt about Sewall Wright’s peaks and valleys metaphor for natural selection, and didn’t get it at all. It seems to be an analogy more complex than the underlying concept.

Chapter 03: Crickets, Sparrows, and Darwins – or, Evolution Before Our Eyes

  • traditionally we think of evolution taking place over eons, but rapid evolution may be more common than thought
  • The chapter than discusses various examples: e.g., crickets in Hawaii that stop making mating calls, and by doing so, aren’t heard by parasitic flies
  • The beak size of the Galapagos finch changed over the course of a single El Niño event as the change in rainfall led to a change in food available
  • Guppy size and age of sexual maturity changes in 2.5 years, after the introduction of predators into the habitat – fast breeding and short guppies escape predatory fish
  • Toad eating snakes in Australia – snakes which are too small to swallow the poisonous cane toad survive, so population becomes smaller over time
  • “Fishery induced evolution” – the term for how overfishing leads to ocean fish also becoming smaller and smaller
  • Lake Apoyeque was formed 1800 years ago as a result of volcanic activity -however fish in that lake have diverged into different species in that period of time.

Chapter 04: The Perfect Paleofantasy Diet: Milk

  • Lactose tolerance is the best studied aspect of rapid human evolution, and shows gene-culture interaction operating in a virtuous cycle
  • Cow milk is higher in protein and lower in fat than human milk. Whales and seals have super-high-fat milk, the consistency of toothpaste. And mouse milk has 2.5 x calories as cow milk. It must have been fun finding that out. I’m remembering the scene in Meet the Parents where Ben Stiller says ‘You can milk anything with nipples.’
  • There has been independent and convergent evolution of lactose tolerance (lactase persistence) in Scandinavian, Bedouin, and Somali populations – all areas with a tradition of keeping cattle.
  • This is the chapter in which I first learned about how the presence of nearby genes allows for statistical analysis about whether a particular gene is present because of genetic drift or natural selection.
  • Milk protein allergies are independent of lactose intolerance.

Chapter 05: The Perfect Paleofantasy Diet: Meat, Grains, and Cooking

  • Zuk’s main counter is “If human beings had the inability to digest grains, ten thousand years is enough time for natural selection to allow the ability to evolve.”
  • There’s archaeological evidence that paleo-humans were in fact eating grains and tubers, contrary to the claims of Paleo dieters.
  • The bow and arrow was the key to increasing the meat component of diet, so it’s not like very early humans were thulping meat all the time.
  • The amylase producing gene also occurs more frequently (as in, more copies of the gene in the genome) in starch eating cultures – another example of rapid evolution in humans.
  • The Japanese’ gut flora get the ability to digest seaweed from horizontal transfer from microbes living on the seaweed itself. This is passed down from mother to child before the child even starts solids.

Chapter 06: Exercising the Paleofantasy

  • TIL that Paleo adherents think that marathoning is artificial and harmful, and promote Crossfit and HIIT instead. To be honest, the Crossfit approach sounds good to me, not because of purported evolutionary reasons, but because it cures boredom.
  • The Active Couch Potato hypothesis: Too much sitting is a problem independent of ‘too little exercise’
  • As I suspected, Europeans are less prone to diabetes on a genetic basis
  • TI also L that NN Taleb also believes in “random exercise” and that fear is a vital component of running.
  • Well, that’s one place where the Doctor Who analogy breaks down.
  • Contrary to the paleo-hate for jogging and marathons, humans may have evolved for intentional endurance running.
  • Humans are unique in being able to walk with their legs straight.
  • Humans burn twice as many calories as other animals while running, but are still able to outrun everyone else over large distances by tiring them out.
  • Running heats up mammals, but as humans have less hair, they can sweat away the heat build up and don’t need to pant it out. Cheetahs with their fur coat, have to stop running after 1 kilometre, or risk hyperthermia.
  • Since humans sweat instead of panting, they are able to alter the frequency of breaths they take while running, which further allows them to expend the same energy over a much larger range of running speeds, compared to other animals, which have an optimum speed for energy consumption.
  • The Endurance Running Hypothesis or Persistence Hunting is that humans would have picked a speed at which the prey would have quickly become exhausted. It need not have been prey – it was also suitable for running away from predators who would have to give up after a point, or running towards carcasses to scavenge before hyenas or lions got there. So, there’s space for a Rincewind quote too: “Dead is only for once, but running away is forever.” and “Rincewind had always assumed that the purpose of running away was to be able to run away another day.”
  • Or, just run animals towards cliff edges.
  • Running is the only sport where you don’t peak at an early age.
  • BDNF is a protein essential to brain formation and function, which is generated by exercise.
  • Barefoot running shoes may not work because a) by the time people start wearing them, they’ve already changed their running form to heel first; and b) regular shoes will have actually changed the shape of your foot over the years

Chapter 07: Paleofantasy Love

  • This chapter is expanded on heavily in Inferior, so I’m not making any special notes here.
  • The one thing that Inferior didn’t cover is that chimpanzee penises are covered in spiny ridges which sweep away the sperm of other chimpanzee males; while human beings lack this gene, so human penises are smooth – and human women can sigh in relief on how much worse it could have been.

Chapter 08: The Paleofantasy Family

  • This chapter, too, is heavily expanded upon in Inferior, and I have no special notes from Paleofantasy.

Chapter 09: Paleofantasy, in Sickness and in Health

  • No special notes, but one special quote: “In an ideal world, natural selection would weed out those who cannot resist disease, but the only world we have is not ideal. It is just the one we have.”
  • “There’s no justice. There’s just me.”

Chapter 10: Are We Still Evolving?

  • Largely a summing up, and a reiteration that the panic about medicine stopping human evolution is both theoretically and empirically false.
  • In this vein, it mentions the Framingham Heart Study, which has tracked people over decades and concluded that evolution is pushing towards higher weight and lower cholesterol.
  • And also cites Tibetan ability to deal with anoxia as another example of rapid human evolution.
  • Also discusses the Japanese team which discovered the gene for the type of earwax (dry and flaky for East Asians, brown and sticky for others) – I wonder if the poor guys got an Ignobel.

 

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