Evolution Week 5 & 6 Flashcards
Define genetic drift.
A powerful mechanism
of evolution, especially
in small populations.
Genetic drift results from…
sampling error.
Sampling error is _______ with a ________ sample.
higher; smaller
Do small populations experience strong or weak drift?
Strong.
Define fixed trait.
There is only one variant of it in the population.
Why is drift an important mechanism of evolution?
Because it alters allele
frequencies over time.
Alleles either become _______ or are lost more _______ in small populations
fixed; rapidly
What is the bottleneck affect?
A nonrepresentative set of alleles for subsequent populations, even after the population size rebounds.
Bottlenecks reduce _____________.
genetic variation
Are rare alleles more likely to be lost during a bottleneck.
Yes
What is the founder effect?
A type of bottleneck resulting from a small number of individuals colonizing a new, isolated habitat.
Give examples of the founder effect.
The variation in flower color among dandelions on different sides of a river.
The reproductive pattern of mountain gorillas with only a few males selected by females.
Lactose intolerance.
What are the 3 types of population subdivision?
No subdivision
Intermediate subdivision
Extreme subdivision
Population subdivision depends on what?
The landscape features and the relative degree of motility of individuals in the population.
Define gene flow.
The transfer of genetic material between populations, usually through migration of an individual or its gametes.
