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Very specifically -- the idea that you can use selective breeding and culling of undesirables to speed up evolution towards a superior human is incorrect. These
by andrewla 2y ago
Very specifically -- the idea that you can use selective breeding and culling of undesirables to speed up evolution towards a superior human is incorrect. These processes, however they are enacted, will result in a more specialized, less robust humanity more vulnerable to disaster, disease, and general unknown environmental pressures because they reduce variation.
Variation is the engine of evolution; the more variation there is inside of a population the more likely it will be able to reach corners of the fitness landscape that cannot be seen a priori but result in adaptive leaps.
If you had to make an attempt at "applied evolution to advance the human race" really you'd do the opposite of eugenics -- you'd encourage more reproduction from a more varied cohort, including "undesirables", especially those with genetic aberrations or significant mental or social issues, but far and away the main thing to do would be to increase the number of people, as that is the greatest contribution to variation within a sexually reproducing species.
Even in the micro selective breeding barely works; an attempt to breed taller people would almost certainly increase the average height while reducing the expected heights of outliers.
- FrustratedMonky 2y agoMaybe we are talking about different meanings of 'fitness'. I'm just saying, we can increase different 'attributes' in animals, so we also can in humans. Humans are not somehow a special case of animal where we can't improve any attributes. You are correct. Just like chickens, where we have breed them to have such huge breasts that they can't survive without assistance. We assist them to live just long enough to be slaughtered.. The chicken group with the over-sized breasts are less 'fit' as a species. But, the goal isn't fitness, it is large breast meat. That decreases overall fitness. Sure, but fitness to do what? You're saying overall fitness as in the group has variation, so adaptable to some future environment. I'm just saying, you can make them taller or bigger. Lets say you breed humans to be more resistant to hot temperatures, but that reduces the variability in the group by reducing the number of cold resistant. Then in future, surprise, the environment gets colder, so the group dies out, because they had lost the cold variations. So what. The goal wasn't how adaptable to some future environment, it was how can I increase attributes I value today in todays environment, like being bigger, faster, etc... Maybe in the future there is a food shortage and all the bigger people starve. That could happen. Of course. This is theoretical, breeding humans is hard. Because we'd also need a way to kill off the outliers. A lot of chickens get tossed in the trash in order to maximize the breast meat of the 'surviving' group. And, I think also, the Eugenics people probably also as you say, miss-understood 'fitness'. Because bigger, faster, etc.. isn't necessarily better. But the perception is that bigger, faster, etc.. would be a super human. Even if that super human might die from catching the flu or something.