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8000 years is basically an eye blink, for evolution and natural selection to select a whole population (through death and differences in reproduction) with thos

8000 years is basically an eye blink, for evolution and natural selection to select a whole population (through death and differences in reproduction) with those who are thoroughly well adapted. Yes, humans might be better off for it than we were 8000 years ago, but that's necessarily not saying much.

danieltillett 11y ago
3000 years is more than enough in humans. The lactase persistence mutation in Europeans basically went from 0% of the population to near 100% in Northern Europeans in 3000 years. This was totally due to a change in diet when adults started drinking animal milk. Evolution speed is proportional to the population size as the rate of new genes appearing is directly proportional to the number of individuals while the speed a gene spreads through the population is proportional to the log10 of the population size. If you increase the population 1000 fold then you get 1000 times the rate of evolution. Because the human population has grown so much since the invention of agriculture the rate of human evolution over the last 10,000 years is more than than the preceding million years.
- Almaviva 11y ago
  There's a difference between some evolution and being totally ideally adapted. Even lactase persistence hasn't spread though the whole human population. Heck, we haven't even totally adapted to walking on two legs yet. (Side note, you don't need to say log10, all logs are proportional to each other by definition.)
  - danieltillett 11y ago
    The lactase gene has not spread through the human population as only a small percentage of the human population drinks milk as an adult. The human population is full of genes that have only partly spread through the population - it is actually a huge problem when studying human genetics since as a species we violate most of the assumptions of population genetics. Humans are actually very well adapted to walking on two legs, what we are not well adapted to is the birthing problems caused by the massive increase in brain size and the rotation of the pelvis required to accomodate walking upright. Yes I know all logs are proportional, but I thought I should be precise or else someone would ask which log ;)

danieltillett 11y ago

3000 years is more than enough in humans. The lactase persistence mutation in Europeans basically went from 0% of the population to near 100% in Northern Europeans in 3000 years. This was totally due to a change in diet when adults started drinking animal milk. Evolution speed is proportional to the population size as the rate of new genes appearing is directly proportional to the number of individuals while the speed a gene spreads through the population is proportional to the log10 of the population size. If you increase the population 1000 fold then you get 1000 times the rate of evolution. Because the human population has grown so much since the invention of agriculture the rate of human evolution over the last 10,000 years is more than than the preceding million years.

Almaviva 11y ago
There's a difference between some evolution and being totally ideally adapted. Even lactase persistence hasn't spread though the whole human population. Heck, we haven't even totally adapted to walking on two legs yet. (Side note, you don't need to say log10, all logs are proportional to each other by definition.)
- danieltillett 11y ago
  The lactase gene has not spread through the human population as only a small percentage of the human population drinks milk as an adult. The human population is full of genes that have only partly spread through the population - it is actually a huge problem when studying human genetics since as a species we violate most of the assumptions of population genetics. Humans are actually very well adapted to walking on two legs, what we are not well adapted to is the birthing problems caused by the massive increase in brain size and the rotation of the pelvis required to accomodate walking upright. Yes I know all logs are proportional, but I thought I should be precise or else someone would ask which log ;)