EEB 390 Lecture Notes - Lecture 6: Allele Frequency, Negative Frequency, Negative Feedback
9 Oct 2020
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Frequency dependence example: perissodus microlepis ( sh) negative feedback example. Fish attach themselves to either sh: mouths that can face left or right. If there more more sh that have mouths facing left, less space available to attach for left math. Sh (negative feedback: as left mouth increases it becomes better to be a right mouthed sh and vice versa. Positive feedback example: some snails have different spiral directions, case where positive feedback (better to have same spiral) Tend to mate with same spiral direction: as frequency increases then tness increases, one allele will go to xation while the other allele will get lost in population. Let"s relax an assumption: no natural selection, no mate preference. There are mutations: no migration, population size is in nite. Note: if random you are increasing diversity these aren"t random mutations but the rate of going from m1 to m2 and m2 to m1.
