Exam 12: Mechanisms of Evolution

An example of evolution that has been readily observed is

Although millions of prairie chickens once occupied Illinois,in 1993 only 50 remained.Starting in 1992,scientists moved almost 300 prairie chickens from large populations in other states to Illinois to ________ Illinois prairie chicken populations.

An example of gene flow would be if pollen from a population ________ plant lands on ________.

Evolution occurs when there are changes in the frequencies of alleles and genotypes in a(n)________ over time.

New alleles arise by

When robins lay a clutch of more than four eggs,their chicks are often malnourished because they have so many to feed.If the robins lay fewer than four eggs,they may not have any viable offspring.As a result,robins typically lay a clutch of four eggs.This is an example of

Two unrelated species evolving to look more similar due to environmental pressures is called

A population of 8,250 mice occupies the sand dunes in a coastal area.A severe hurricane washes out several miles of sand dunes.As a result,only 50 mice remain.The population has experienced

Both mammals and octopi have evolved similar eye structures.This is an example of

Convergent evolution occurs when natural selection causes distantly related organisms to

For a population to evolve,there must be genetic differences between organisms in that population.These differences arise by

Explain why a mutation in an individual's skin cells does not directly contribute to evolution.

The following image is an example of

The only mechanism of evolutionary change that is not influenced by chance events is ________.

Which of the following is NOT a step in the evolutionary process?

Two different species may have similar features because of