Forces of Evolution Flashcards
What is the definition of evolution?
Change of allele frequencies in a population over time
What creates new alleles to a population?
Mutations
What is a mutation?
A change in the genetic code
What is gene flow?
When a new gene moves from one place to another
What is gene flow referred in humans?
Admixture
What is gene flow referred in non-humans?
Hybridization
What happens if gene flow stops between two populations?
Mutations accumulate and populations’ genes start to diverge
What is genetic drift?
When there is random change of allele frequency in a population
Genetic drift: what’s the founder effect?
When a group of organisms/humans causes descendants to look super similar
Genetic drift: what’s a bottleneck?
When there’s a sudden decrease in genetic variation
Genetic bottlenecks are mostly associated with what?
High mortality events
Give two examples of high mortality genetic bottleneck events
Diseases, political turmoil, mass extinction
What is natural selection?
When some phenotypes give an edge over other phenotypes and cause their frequency to change
Natural selection: what is a directional pressure?
When environment selects one trait over another so its allele frequency increase
Natural selection: what is balancing pressure?
When population is selected the intermediate one over the extremes
Natural selection: what does it mean for diverging pressure?
When two traits are equally advantageous and their populations start to diverge away
What is sexual selection?
When phenotypic traits are selected for reproduction
Hardy-Weinberg equilibrium: what does p represent?
p = frequency of dominant allele
Hardy-Weinberg equilibrium: what does q represent?
q = frequency of recessive allele
Hardy-Weinberg equilibrium: what does q^2 represent?
q^2 = frequency of homozygous recessive
Hardy-Weinberg equilibrium: what does p^2 represent?
p^2 = frequency of homozygous dominant
Hardy-Weinberg equilibrium: what does 2pq represent?
2pq = frequency of heterozygous
