Natural Selection

Front

What additional evidence did Darwin use to support his explanation of finch species evolution on the Galapagos Islands?

Back

The finch species lived in different habitats on different islands, which isolated them from one another.

Front

As explained by Darwin’s theory, which condition allows a rabbit population to evolve by natural selection when a disease strikes? Options: The disease affects adult and juvenile rabbits equally. The disease reduces the ability of the rabbits to reproduce. Some rabbits are resistant to the disease, and they pass the resistance to their offspring. No rabbits are resistant to the disease, and all die when the disease strikes them.

Back

Some rabbits are resistant to the disease, and they pass the resistance to their offspring.

Front

Situation causing evolutionary change NOT due to natural selection:

• A volcano erupts and kills many individuals in a population.
• A mutation produces sea stars that are less visible to predators.
• An insecticide is sprayed in a community to combat mosquitoes.
• Cattle are treated with antibiotics to prevent the spread of infections.

Back

A volcano erupts and kills many individuals in a population.

Front

What most likely caused the change in crab color distribution at the beach?

Back

A change in beach color made medium-tan crabs the most visible to predators.

Front

How could genetic variation that contributes to evolution occur in an isolated population?

Back

A mistake in DNA replication before meiosis produces an organism that is better able to outrun predators.

Front

The figure shows how natural selection of a single-trait gene affects lizard survival.

Which of the following most likely causes the changes in allele distribution?

• The allele for light gray coloration disappears from the population.
• The allele for black coloration decreases fitness and becomes less common.
• Medium gray coloration in lizards appears to be a neutral mutant allele.
• Black and medium gray lizards are less visible to predators.

Back

The allele for light gray coloration disappears from the population. This may be because light gray lizards are more visible to predators and therefore they might be less likely to survive and reproduce.

Front

Grass plants in a population range in height from 6 cm to 25 cm. The short plants receive little sunlight, and the tall plants are eaten by grazing animals. Which statement best describes the effect of natural selection on the grasses?

Back

Because average height grass plants are favored, stabilizing natural selection is occurring.

Front

Which evidence would be most useful for identifying a pattern of punctuated equilibrium in an evolutionary lineage?

Options: Similar bone structures among mammal species alive today, An identical genetic code in use among all species alive today, Fossil sequences that show gradual changes over long spans of geologic time, Fossil sequences that show rapid changes over brief spans of geologic time

Back

Fossil sequences that show rapid changes over brief spans of geologic time

Front

Which of the following best illustrates natural selection?

Back

An organism with favorable genetic variations will tend to survive and breed successfully.

Front

Which of the following is NOT part of the mechanisms of natural selection?

• Organisms produce more offspring than can survive.
• Disease and natural disaster will limit population growth.
• Species today descended with modifications from ancestral species.
• Organisms with advantages will survive and reproduce.

Back

Disease and natural disaster will limit population growth.