microevolution Flashcards
microevolution
change in allele frequency in a population
gene pool
collection of all alleles in a popultion. sex shuffles these alleles every generation
hardy-weinberg formula
p^2 + 2pq + q^2=1
p is dominant and q is recessive
can use to test for evolution in a popultion. if expected=observed then no effect of evolution on genotype
evolutionary mechanisms that affect allele freqencies
-natural selection
-non-random mating
-mutation
-genetic drift
-gene flow
2 causes of genetic drift
genetic drift= random event that causes change in allele frequency
**greater effects on SMALL POPULATIONS
- founder effect (founder, new population eg. blue family)
- genetic bottleneck (survivor eg. almost extinction)
fixation
when genetic drift leads to only one allele left in the population
gene flow
alleles mve between populations
immigration/emigration
–>gene flow increases allae frequency between the two populations. overtime populations’ allele frequency will become identical
mutation
causes genetic variation in a population
adaptive vs. non adaptive evolution
adaptive= Evolution that results in
a BETTER FIT between
individuals and their environmenteg) natural selection
non-adaptive =chance events eg) genetic drift, gene flow, mutations
hardy-weinburg principle assumes that
no evolutionary changes occur (natural selection, gene flow, genetic drift, mutations, and non-random mating)