Review Practice: Evolution

Which statement describing a cause of extinction includes the other three?

• Members of the extinct species were unable to compete for food.

• Members of the extinct species were unable to conceal their presence by camouflage.

• Members of the extinct species lacked adaptations essential for survival.

• Members of the extinct species were too slow to escape from predators.

The Florida panther, a member of the cat family, has a population of fewer than 100 individuals and has limited genetic variation. Which inference based on this information is valid?

• These animals will begin to evolve rapidly.

• Over time, these animals will become less likely to survive in a changing environment.

• These animals are easily able to adapt to the environment.

• Over time, these animals will become more likely to be resistant to disease.

According to this diagram, the DNA of which pair of organisms would show the greatest similarity?

• penguin and turtle

• horse and donkey

• snake and tuna

• turtle and rabbit

Classification of organisms is important because:

• It helps in identifying and studying organisms systematically.

• It allows us to understand the relationships among different organisms.

• It makes organisms look more attractive.

• It increases the number of species.

Base your answer to the question on the diagram below, which represents possible relationships between animals in the family tree of the modern horse, and on your knowledge of biology. Miohippus has been classified as a browser (an animal that feeds on shrubs and trees) while Merychippus has been classified as a grazer (an animal that feeds on grasses). One valid inference that can be made regarding the evolution of modern horses based on this information is that

• Eohippus inhabited grassland areas throughout the world

• Pliohippus had teeth adapted for grazing

• Equus evolved as a result of the migration of Pliohippus into forested areas due to increased competition

• ecological succession led to changes in tooth structure during the Eocene Epoch

Provide two pieces of information that is used to classify organisms into specific taxa.

• Physical characteristics and genetic information

• Habitat and diet

• Color and size

• Age and weight

The diagram indicates that a common ancestor for species C and E is species

• F

• G

• H

• K

Scientists compared fossil remains of a species that lived 5,000 years ago with members of the same species living today. Scientists concluded that this species had changed very little over the entire time period. Which statement best accounts for this lack of change?

• A. The environment changed significantly and those offspring without favorable characteristics died.

• B. The environment changed significantly, but the species had no natural enemies for a long period of time.

• C. The environment did not change significantly and those offspring expressing new characteristics survived their natural enemies.

• D. The environment did not change significantly and those offspring expressing new characteristics did not survive.

Explain why species B and C are more closely related than species A and C are.

• Because species B and C share a more recent common ancestor.

• Because species A and C have more differences in their DNA.

• Because species B and C live in similar environments.

• Because species A and C evolved at the same time.

A current proposal in the field of classification divides life into three broad categories called domains. This idea is illustrated to the right. Which concept is best supported by this diagram?

• A. Evolutionary pathways proceed only in one set direction over a short period of time.

• B. All evolutionary pathways will eventually lead to present-day organisms.

• C. All evolutionary pathways are the same length and they all lead to present-day organisms.

• D. Evolutionary pathways can proceed in several directions with only some pathways leading to present-day organisms.