Unit 1 Flashcards
What is the process through which species adapt and change over time?
Natural Selection
-living organisms reproduce
-more offspring are produced than can survive
-offspring are genetically unique
Tracks changes, due to natural selection, in a population
Population genetics
What is allele frequency?
the relative frequency of an allele at a particular locus in a population.
What do changes in allele frequency from one population to the next mean?
that the population is evolving
What is genotype frequency?
The frequency or proportion of genotypes in a population.
Hardy-Weinburg Equilibrium Conditions
-no gene flow
-no natural selection
-no mutation
-random mating
-no genetic drift
A population in HWE is…
NOT evolving.
Allele frequencies equation
-p + q = 1
-p is the frequency of the dominant allele
-q is the frequency of the recessive allele
Genotype frequencies equation
– p^2+2pq+q^2=1
-p^2 is the frequency of one homozygous dominant genotype
-2pq is the frequency of the heterozygous genotype
-q^2 is the frequency of the other homozygous recessive genotype
The diversity of PHENOTYPES in a population
Population variance
The diversity of ALLELES within the population.
Genetic variance
What changes allele frequency due to random chance?
Genetic drift
What changes allele frequency due to migration of individuals?
Gene flow
What changes allele frequency by introducing new alleles?
Mutation
What changes allele frequency by sexual selection?
Nonrandom mating
What changes allele frequency by influence of phenotypes?
Environmental variance
The process of natural selection increasing the frequency of beneficial traits, decreasing the frequency of deleterious traits.
Adaptive evolution
Remember, natural selection isn’t selecting for/against an allele,
it is selecting for/against a phenotype.
A measure of an individual’s fitness compared to the fitness of others in population
Relative (evolutionary) fitness
Stabilizing selection
selects for the middle, not the extreme
Directional selection
selects for one extreme depending on benefit; gradient
Diversifying selection
selects against the middle type; all white or all black in wolf ex.
How do taxonomic groups move?
from more inclusive to less inclusive
How to you name in taxonomy?
Binomial nomenclature system: Genus species (italicized)
