Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
microevolution
|
change in allele frequencies in a population over generations
|
|
|
|
three mechanisms that alter allele frequency and bring about most evolutionary change:
|
1. natural selection (good change)
2. generic drift 3. gene flow |
|
|
|
generic variation
|
is caused by differences in genes or other DNA segments
|
|
|
|
average heterozygosity
|
measures the average percent of loci that are heterozygous in a population
|
|
|
|
sources of genetic variation:
|
1. formation of new alleles
2. altering gene number or position 3. rapid reproduction 4. sexual reproduction |
four kinds
|
|
|
Hardy-Weinberg
|
describes a population that is NOT evolving
|
|
|
|
frequency of an allele in a population
|
p + q = 1
p = % homozygous dominant allele q = % homozygous recessive allele |
equation
|
|
|
frequency of individual genotypes
|
p² + 2pq + q² = 1
p² = % homozygous dom. genotype 2pq = % heterozygous genotype q² = % homozygous rec. genotype |
equation
|
|
|
conditions for Hardy-Weinberg equilibrium
|
1. no mutation
2. random mating 3. no natural selection 4. large population 5. no gene flow |
five conditions
|
|
|
genetic drift
|
describes how allele frequencies fluctuate unpredictably from one generation to another
|
|
|
|
founder effect
|
occurs when a few individuals become isolated from a larger population
|
one form of genetic drift
|
|
|
bottleneck effect
|
a sudden reduction in population size due to a change in the environment.
|
one form of genetic drift
|
|
|
gene flow
|
movement of alleles among populations
|
reduces variation
|
|
|
three modes of selection
|
1. directional
2. disruptive 3. stabilizing |
|
|
|
sexual selection
|
natural selection for mating success
|
|
|
|
sexual dimorphism
|
marked differences between the sexes in secondary characteristics
|
peacocks
|
|
|
intrasexual selection
|
competition of one sex (often males) for mates of the opposite sex
|
good kind
|
|
|
intersexual selection
|
often called mate choice, individuals of one sex (females) are choosy in selecting mates
|
double edged sword
|
