3) Genetic Drift

What is genetic drift?

the process by which chance events in a population change the allele frequencies in that population

What is the process by which chance events in a population change the allele frequencies in that population?

genetic drift

What does genetic drift lead to?

a loss of genetic diversity in a population’s gene pooll

What leads to a loss of genetic diversity in a population’s gene pool?

genetic drift

In small populations, allele frequencies are more likely to be affected by chance events such as?

disease, predation, or natural disasters

In what kind of population are allele frequencies more likely to be affected by chance events such as disease, predation, or natural disasters?

small populations

In large populations, allele frequencies change due to what?

natural selection

In what kind of population do allele frequencies change due to natural selection?

large populations

What is a fixed allele?

an allele that is presenting every individual, and therefore cannot be removed from the population by natural selection

What is an allele that is presenting every individual, and therefore cannot be removed from the population by natural selection?

a fixed allele

What are the two processes that cause populations to become small enough for genetic drift to occur?

the bottleneck effect and the founder effect

The bottleneck effect and the founder effect are the two processes that cause what?

populations to become small enough for genetic drift to occur

What does the bottleneck event occur?

when an event, such as flood, fire, or over hunting, greatly reduces the size of a population

What occurs when an event, such as floods, fires, or over hunting greatly reduces the size of a population?

the bottleneck event

When does the founder effect occur?

after a small number of individuals move into a new area

What occurs after a small number of individuals move into a new area?

the founder effect