Mechanisms of Evolution

Genetic drift is change in the allele frequency of a population due to...

• random chance
• natural selection
• non-random mating (sexual selection)
• artificial selection

Which of the following is true?

• Gene pool frequencies do not change as a result of migration in or out of a population.
• Gene flow occurs only as a result of isolation of a small population.
• Gene flow can cause new alleles to enter a population's gene pool.
• Gene flow is due the the selection of the most favorable traits.

A few deer wander out of their native woods into a completely new park where no deer had ever been before. They go on to create an entirely new population.

• Genetic Drift
• Natural Selection
• Non-random mating
• Mutation

Yellow toucan birds seek out one another to make babies together and tend to avoid the green toucan birds.

• Genetic Drift
• Non-random mating
• Gene flow
• Mutation

During gestation (pregnancy), a developing male pig had a change in his genetic code. The result was that he was able to walk and do karate.

• Genetic Drift
• Non-random mating
• Mutation
• Natural Selection

Bats are common in Texas, especially in rocky regions. Bats with longer hang claws have demonstrated higher fitness because of their ability to cling to rock while resting.

• Natural Selection/Adaptation

• Non-random mating
• Gene Flow
• Mutation

Wolves from the Arizona mesa were transferred to the Colorado Rockies after a forest fire destroyed their habitat. They quickly became part of the local pack and had offspring.

• Mutation
• Natural Selection
• Genetic Drift
• Gene Flow

7 Wild Mustangs were taken from the prairies of Iowa after a Texan Rancher purchased them and provided them with their own pasture. Those 7 Mustangs eventually became 122.

• Genetic Drift (Founder Effect)

• Non-random mating
• Gene flow
• Mutations

What does the picture represent?

• Founder Effect
• Mutations
• Bottleneck effect
• Gene Flow

Which of the following is an example of the bottleneck effect?

• Cheetah populations reach their lowest levels with reduced diversity and as they rebound are so genetically similar they appear to be inbred.

• Affected individuals with blue skin can trace their ancestry back to one of the first settlers in the region.

• The environment of a fox population changes and over time foxes who are white survive and pass on their genes to their offspring.

• Humans choose two dogs they like the characteristics of and breed them together.