Darwin's Theory of Natural Selection

Darwin theorized that natural selection is—

• A. The mechanism of evolution

• B. How modern species have come to exist

• C. The explanation for beak variation in finches.

• D. All of the above

An example of genetic variation in an organism is —

• A. Fruit without seeds

• B. Albinism

• C. Presence of dimples

• D. All of the above

Darwin's theory of evolution proposed

• A. extinct species are not related to living species.

• B. artificial variation results in some species being more fit to survive.

• C. species change over time by the more favorable traits being passed down to offspring.

• D. none of the above.

"Survival of the fittest" is another way of describing—

• A. Adaptive radiation

• B. Convergent evolution

• C. Diversity

• D. Natural Selection

Which of the following statements is true?

• A. Evolution can occur in one generation over many years.

• B. Evolution can only occur through thousands or millions of generations in a population.

• C. Evolution can be seen in one organism in one lifetime.

• D. All of the above.

The evolution of beak sizes in Galapagos finches is a response to

• A. How finches use their beaks for the food or seeds available.

• B. The finches using the beak more, the beak changing, then passing that trait on.

• C. Whether the populations interbreed

• D. The nutritional content of the seeds grew smaller birds.

According to natural selection, which of the following results would be considered a beneficial mutation to an organism?

• A. resistance to a virus

• B. formation of cancer cells

• C. inability to undergo sexual reproduction

• D. stopping the production of an essential protein

A mutation occurs in a species of bird that eats seeds. The new mutation shapes the end of the beak in a new way that allows the birds to crack open seeds faster. What will most likely occur with the mutation over time?

• A. Since the mutation only affects one organism, it will most likely disappear from the gene pool.

• B. Since the mutation causes the bird to be better adapted, it will be passed on to its offspring, and over many generations could cause the species of bird to evolve.

• C. The mutation will be passed on to the offspring of the bird, but will stay only in the immediate family of the bird.

• D. The mutation never could have existed because mutations cannot occur in DNA.

Black grasshoppers thrive in the wild, while green grasshoppers grow in limited numbers in the wild and thrive near cultivated (farm) land. The two species are eaten by the same predators and compete for the same food source. As more land is cultivated to farmland, what will happen to the two populations?

• A. The black grasshoppers will outbreed the green grasshoppers.

• B. The green grasshoppers will outnumber the black grasshoppers.

• C. The black grasshoppers will find new wild lands in which to live.

• D. Both grasshoppers will die out eventually from resource pressures.

Which characteristics of a population would most likely indicate the lowest potential for evolutionary change in the population?

• A. asexual reproduction and few mutations

• B. asexual reproduction and many mutations

• C. sexual reproduction and few mutations

• D. sexual reproduction and many mutations