4 ms·
> In subsequent bubonic plague outbreaks over the next 400 years, mortality rates decreased. This could have been the result of changing cultural practices, pat
by yakak 4y ago
> In subsequent bubonic plague outbreaks over the next 400 years, mortality rates decreased. This could have been the result of changing cultural practices, pathogen evolution, or human genetic resistance.
Multiple rounds.
- Retric 4y agoNone of which where anywhere near deadly enough to change European genetics. In theory it’s possible a 50% bottleneck to push a trait from 45% of a population to at most 90% at the extreme end. However, 45% of a population having some trait(s) without earlier evolutionary pressure is extremely unlikely. Thus, the prevalence of those traits would trace back to that earlier genetic pressure.
- yakak 4y agoGenes that already provide a protective function alone but cause problems in combinations like 2 copies or with other similarly protective genes are naturally going to stay around but not become prevalent. A serious event or events creates a situation where these genes become common enough to hit the bad combinations much more often. Naturally not everyone has type I diabetes and MS.
- Retric 4y agoSure, but again all that changed was a slight change in the frequency of this interaction not the existence of it. It’s simply not enough change at the population level to turn extremely rare genetic disorders into common problems.