15: Microevolution Flashcards
Population
members of a single species occupying a specific area and reproducing with each other
Microevlution
evolutionary changes within a population
Population Genetics
all alleles in the gene loci of a population make up the gene pool
- used to analyze evolution within a population
Hardy Weinberg Principle
equilibrium occuring if a population randomly mates with one another allowing for mathematically determined gene frequencies
- can only be studied in laboratory setting
What does microevolution do to Hardy Weinberg principle?
disrupts it, changing the gene frequency
Hardy Weinberg binomial equation
p2 + 2 pq + q2
- p & q represent the freq of two alleles for the genotype
Why doesn’t Hardy Weinberg principle work?
- conditions rarely are met in real world
- allele freq continually change and microevolution occurs
- only describes factors that cause evolution
In order for natural selection to change allele frequencies it must?
affect the phenotype associated with the gene
- i.e. industrial melanism
What factors cause microevolution? (5)
- Mutations
- Gene flow
- Nonrandom mating
- Genetic drift
- Natural selection
What does mutation introduce into a population?
variation, which is adaptive if it helps adjust to environment
gene flow
when does it occur? what does it cause?
- gene migration
- occurs when breeding members of a population leave a population or new members enter
- causes new alleles to be introduced
What does continual gene flow do?
- decreases differences in alleles
- prevents speciation
Types of non random mating
- Assortive Mating: select mate with similar phenotype
- sexual selection: select mate with favorable traits
genetic drift
chance events that cause allele frequency to change
bottleneck effect
when event or catastrophe drastically reduces # of population
- variation may be reduced
- changes allele frequencies
