Why do people underestimate natural selection so much?

**manu15151513** · 08-04-2021, 07:54 PM

If a group of northern Italians moved to southern Italy in an obviously non-modern context, the recurrence of skin cancers, folic acid deficiency and other problems associated with UV rays such as sunburn would be a little more recurrent, and consequently since the dark skin protects from all this those with dark skin would have slightly more children than those with light skin. Even if this equated to only 1.5% of the bell curve mean shift (actually probably more), this would mean that in sixteen generations the bell curve would average 24% darker than in sixteen generations before, in just about five hundred years. That is, in just five hundred years we would obtain approximately the same pigmentation as in today's southern Italy and its distribution. Or the coastal areas of the Marche are sunnier than the nearby inland, so even just three hundred years, about ten generations, could be enough with a shift of the average bell curve of 10% (only 1% for generation) to make the coastal Marche visibly darker, albeit slightly, by internal ones. You can think in these terms for a multitude of things. If, for example, people with unibrow had a very small but present reproductive advantage because a very small greater probability of reproducing because the sweat, due to the heat and hard work, would not run into your eyes making you more vulnerable to animals, accidents, murders and so on (0.65% bell curve per generation), already in just two thousand years the unibrow would have increased +39% of people with it; Why the fuck does everyone think natural selection is so slow when it can be lightning fast and super specific?

A very small percentage of the population had grandchildren, three-grandchildren, and so on. In the past, even until very recently, life was hard and death was very normal, so even if a feature provided a very subtle indirect and probabilistic advantage (0.5% +, so 99.5% of people don't change anything having that characteristic or not) this could fully assert itself in a few centuries.