Evolution Flashcards
What is evolution?
the change over time in the proportion of individuals in a population differing in one or more inherited traits
What is sexual selection?
the non-random process involving the selection of alleles that increase the individuals chances of mating and producing offspring
Sexual selection may lead to
sexual dimorphism
Sexual selection can be due to
male-male rivalry and female choice
When does genetic drift occur?
when chance events cause unpredictable fluctuations in allele frequencies from one generation to the next
Why is genetic drift more important in small populations
alleles are more likely to be lost from the gene pool
Why is a gene pool altered by genetic drift?
because certain alleles may be under-represented or over-represented and allele frequencies change
When can the rate of evolution be rapid?
When selection pressures are strong
What does the Hardy-Weinberg (HW) principle state?
In the absence of evolutionary influence, allele and genotype frequencies in a population will remain constant over the generations
What can the HW principle be used to determine?
Whether a change in allele frequency is occurring to a population over time. Changes suggest evolution is occurring
What is male-male rivalry?
large size or weaponry increases access to females through conflict
What does female choice involve?
females assessing the fitness of males
When do population bottlenecks occur?
When a population size is reduced for at least one generation
How do founder effects occur?
Through the isolation of a few members of a population from a larger population
The gene pool of the new population is not ______________ of that in the original gene pool
(founder effects)
representative
(founder effects)
What are selection pressures?
the environmental factors that influence which individuals in a population pass on their alleles.
What are the conditions for maintaining the HW equillibrium?
no natural selection, random mating, no mutation, large population size, no gene flow
What is the Hardy-Weinberg formula?
p² + 2pq +q² = 1
p =
frequency of dominant allele
q =
frequency of recessive allele
p² =
frequency of homozygous dominant genotype
2pq =
frequency of heterozygous genotype
q² =
frequency of homozygous recessive genotype
What is fitness?
Fitness is an indication of an individuals ability to be successful at surviving and reproducing
