m_huber
Muse
- Joined
- Nov 4, 2007
- Messages
- 828
Are you evolutionists having trouble figuring out whether selection pressures increase or decrease the diversity of a population?
The real question would be which selection pressures you are talking about. For example, if the selection pressure were related to the climate becoming substantially warmer, you would expect that many of the organisms affected would have to migrate, go extinct, or evolve. Diversity would decrease as animals go extinct, then increase as new animals fill the niches that are newly opened. The evidence of this is how well suited to their environments modern animals are. Given that the climate does change, animals must also change in order to stay fit within a given geographic area.
If the selection pressure were, instead, some type of predator, then you would find that diversity would not change so much as the prey would simply adapt unidirectionally to the best version of itself that could evade the predator.
You could also have selection pressures associated with disease, albedo, humidity, ocean levels, mountain ranges forming or being destroyed, rivers meandering, geographic boundaries being formed or destroyed in general, allowing populations to mix, or a whole host of other possibilities. One that generally doesn't effect non-microscopic animals is antibodies. We big animals are generally able to either spot poison, or figure out that when Bob ate it, he died. Perhaps this is an intelligence selection..
