I saw a comment on an answer to another question that touched on an interesting topic:
keeping diversity is useful for parameter exploration or to adapt to future environmental change
My initial thought was that evolution doesn't "know" about the future, so natural selection might decrease genetic diversity even if it meant dooming the species in the long term.
On the other hand, species that have low genetic diversity may be more likely to go extinct eventually. So perhaps over time the surviving taxa are those that have evolved mechanims to "hedge their bets" against future environmental changes.
It's clear that some of the parameters that affect genetic diversity within a species (e.g. mate selection, mutation rate) are heritable, but it's unclear to me how the short-term processes of natural selection relate to the extremely long-term processes of speciation and extinction. This gets into some of the same issues as group selection — how can natural selection, acting on individuals, lead to traits that benefit entire populations or clades? (Perhaps this simply cannot happen.)
Has any work been done on the topic of extinction resistance or the evolution of mechanisms to create and preserve diversity within populations or taxa?
This is a big question so I don't expect a full answer here. I'm just looking for some references as a starting point to learn more about this topic.