Which of the following is an example of geographic isolation?
a population of salmon dies out because they cannot find food.
a zebra with a long mane moves into a population of zebras with short manes.
a population of squirrels is separated by a mountain range and cannot interbreed.
two populations of rabbits are forced together after a flood.
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which of the following statements is true?
extinction speeds up the evolution of other species.
earth has only experienced one mass extinction in its history.
speciation is caused by a reduction in gene flow.
genetic diversity can be increased by genetic drift.



low genetic diversity
a population survive
increases the risk of extinction
can cause genetic drift
is the result of genetic mutation


a species is endangered if it
no longer exists anywhere on earth
is in danger of becoming extinct
is not native the environment
has high genetic diversity
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which of the following statements is true?
gene flow evens out genetic differences between populations.
genetic drift increases the genetic differences between populations.
natural selection, mutation, and genetic drift are random events.
the bottleneck effect increases the genetic diversity of a population.