Question

Hello. I have been wondering something of which I consider interesting: Why are populations that are more diverse usually more stable? And, why would a diverse population be more resistant to disease, predation, etcetera? Please answer, thank you and Shana Tova.

Answer 1

It is going to depend on what you consider stability. The pirahã are not very diverse at all in their population and are extremely stable. They also have a frustratingly complicated language and no concept of numbers which keeps foreign influence out for the most part. A diverse population would be more resistant to disease because of simple biology. The more sources for possible resistance the better the heterogeneous pool will be at resisting disease. You also have to take in to consideration things like the availability of modern medicine and the ability to be isolated during illness. Predation? I would need you to clarify what you mean. Invasion is a tricky one and the answer is going to depend on what school of thought you take on the subject. Personally I think it has to do with the fact that many of the worlds more diverse population centers are also many of the worlds largest population centers which make them less prone to invasion on that basis alone. And in genetically diverse population most of the members would survive even some members became susceptible to disease.. in genetic terms it may be due to lack of resistance to the disease for the susceptible or presence of resistance gene/absence of susceptible genes in resistant ones. same principle to predation/invasion also, in those case some of the members would be having advantage of genetic propotion which-different from rest of the population.