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View submission: Ask Anything Wednesday - Biology, Chemistry, Neuroscience, Medicine, Psychology
Textbook often state that measurable evolutionary change takes thousands of generation - but the scientific literature is full of examples of much faster change than that. Some examples off the top of my head:
1. Lactase persistence[1] - the ability to digest milk into adulthood - is found in some but not all human populations due to selection after the domestication of animals for milk consumption.
1: https://en.wikipedia.org/wiki/Lactase_persistence#Evolutionary_history
2. People whose ancestors lived at high altitude (e.g. Tibetans) have physiological adaptations[2]to help them.
2: https://en.wikipedia.org/wiki/High-altitude_adaptation_in_humans
3. The human brain, although the largest relative to body size in nature, has shrunk over the past 3000 years. This somewhat speculative paper[3]suggests that civilization may mean that we no longer need to rely on ourselves as much, but on technology, and our brain may have shrunk to conserve energy.
These are all within the past few thousand years.
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