3.5 Mechanisms of Evolution Flashcards
Understand and know all mechanisms of evolution (15 cards)
What are the factors that effect Allele frequency?
Mutation, Gene Flow, Non-random mating, Genetic Drift, Natural Selection
How does Allele frequency lead to evolution?
changes of percentage or frequencies ofalleles within populations are small events that lead to evolution
Mutation, related to evolution how?
inheritable mutations can affect an entire gene pool by the addition of new alleles to the population
Gene Flow, related to evolution how?
Gene flow specifically refers to Migration
it is net movements of alleles from one population to another due to migration of individuals
Non-random mating, related to evolution how?
mating of individuals on the basis of mate selection driven specifically by phenotypes)
ex. phenotipyc preferences
ex. inbreeding
Genetic Drift, related to evolution how?
change due to chance events to a breeding population
What are the two types of genetic drift?
The founder effect and the bottleneck effect
Founder Effect
a change that occurs when a few individuals start a new population
Bottleneck Effect
Change due to rapid population decrease
Natural Selection, related to evolution how?
If one allele gives a slight advantage, it will increase in frequency
What are the 4 main ways that we see natural selection affect a population?
Stabilizing Selection, Directional Selection, Disruptive Selection, Sexual Selection
Stabilizing Selection
common in stable environments
when the intermediate phenotype is favoured over extreme phenotypes so they are eliminated. However, it reduces variation
Directional Selection
favours one extreme over the other, common during environmental change
Disruptive Selection
favours both extremes over the intermediate (so either very strong/large and very weak/small over medium strength/size)
Sexual Selection
Selection based on mating competition and choices by females.
