Evolution of Populations Flashcards
Evolution
a genetic change in characteristics of a population through time
Gene pool
all the genes in a population
Microevolution
change within a species
Macroevolution
formation of a new species
Population
a group of individuals of the same species living in the same place at the same time
Genetic Equilibrium
A population that is not evolving
Hardy-Weinberg principle
describes a population at genetic equilibrium
- large population
- isolated
- no mutation
- random mating
- no natural selective pressures
p in Hardy
dominant allele
q in Hardy
recessive allele
Lethal mutations
They dissappear
Neutral mutations
Don’t lead to anything
Beneficial mutations
leads to survival and reproduction
Natural Selection
A process by which nature selects characteristics of a population best suited to the environment
Directional selection
Changes a species to one extreme
Stabilizing selection
takes the extremes, and keeps the “normal”
Disruptive selection
gets rid of the normal, keeping the extremes
genetic drift
process in which chance events lead to random fluctuations in allele frequencies.
Bottleneck effect
severe reduction in a population due to a natural disaster or instense selective pressure
Founder’s effect
occurs when a few individuals become isolated from a larger population
