3 ms·
> being grouchy and tired all the time isn't enough to kill people or prevent them from reproducing. It may not be enough by itself, but it's easy to imagine i
by im3w1l 6y ago
> being grouchy and tired all the time isn't enough to kill people or prevent them from reproducing.
It may not be enough by itself, but it's easy to imagine it being the last straw so to speak. An alternative explanation could be that society needs a certain percent of night owls. That there is a niche in which it's beneficial.
- ojnabieoot 6y agoIt’s a huge mistake to go grasping for an adaptive explanation to every single mutation. The null hypothesis is that “this disorder doesn’t kill people before sexual maturity, or provide some reproductive gain” and there’s literally no evidence for anything else. You are speculating about a solution to something that isn’t actually a mystery. And as I said in another comment, the disorder this mutation causes is not normal “sleep late, wake late” night owl syndrome.
- im3w1l 6y agoIf the variant is prevalent then I can only see two explanation: either it is(was at some point) adaptive, or there was some kind of founder effect - where a small group of people that just happened to have it and become hugely genetically successful for other reasons.
- ojnabieoot 6y agoThe thing is that it isn’t that prevalent! Please look at the link I posted with the data - almost every ethnic group listed has less than 1% prevalence. The group it is most prevalent in is Ashkenazi Jews (3.4%), who have an unusual history that discouraged cross-ethnic relationships for millennia, and who are prone to many recessive genetic disorders that would have otherwise been more diluted. These mutations are not so prevalent because Ashkenazi Jews needed them to survive European persecution: they are the consequence of said persecution. There really does not have to be an adaptive explanation or an adaptive “coincidence” like you suggested with the founder effect. Please please please please look at the data.
- im3w1l 6y agoThat's still quite a lot of people in absolute numbers. I'm not sure I buy that so many can have it without any reason at all.
- Armisael16 6y agoThe reason would be that there are a lot of people in general and the trait isn’t harmful enough to be weeded out. Humans are not perfectly optimized packages.
- im3w1l 6y ago> trait Just want to mention this mistake. We are talking about a gene variant, not a trait. Phenotype inheritance is much more complicated than genotype inheritance.
- ojnabieoot 6y agoA common misconception about natural selection is that it optimizes species. It’s really more about “this has bugs but it’s good enough to cut a release branch.”
- lmilcin 6y agoIt might be simpler explanation. Homo Sapiens evolved in Africa where there are no long winter nights and huge variations of daily cycle throughout the year. Also humans can do shit in sunlight only. Like hunt. Then we moved to a different zone where there is longer nights and then we learned to do stuff that could be useful to be done "after hours". The pressure on good nights sleep immediately after dark lessened. Actually, people had to learn to work in the dark because in central and northern Europe there isn't much sunlight in the winter. Even in daytime there is usually overcast and no direct sunlight.