BIOL 2400 Study Guide - Repeatability, Aneuploidy, Paleoproterozoic
Document Summary
Stabilizing selection occurs when deviations from the current character state have lower fitness natural selection can cause adaptive change, but also impose powerful constraints on the evolution of features of an organism if a specific gene has a vital function and it is changed: mutations that improve the function of essential genes are rare, usually the changes are for the negative thus essential genes are under strong selective constraints against any kind of change, natural selection can prevent new gene from arising and limit evolutionary change. Redundancy to get new gene you need the constraint of stabilizing selection to be released: most common way is for there to be a redundant copy of a gene (arises through duplication, one copy fulfills vital function, other diverges through mutation, susumu ohno gene duplication essential for large scale evolution believes natural selection prevents change most of the time, duplication doesn"t.
