________ features are features in different species that are the same in structure owing to inheritance from a ________.

The auricular muscles of human beings and the wings of ostriches are examples of _______ characters.

True or false: Charles Darwin was the first person to perceive common descent with modification.

The co-discoverer of natural selection was ________.

Following the publication of On the Origin of Species, the evolutionary principle of ________ was quickly accepted by most scientists, but the importance of __________ would not be accepted by most authorities until midway through the twentieth century.

The principle of common descent with modification holds that groups of living things can undergo modifications that, over time, can lead to the formation of new _______ and that all living things on Earth are descended from a _______.

The principle of natural selection holds that some traits will confer a _______ to individual organisms and that these traits will accordingly become more _______ over time in a population of organisms.

Evolutionary theory supports the idea that humans are _______ other organisms and thus are not _______ from other living things.

Using evolutionary principles, explain why large ears might be expected to evolve in a terrestrial plant eater such as a rabbit or deer but not in an aquatic mammal such as a seal.

In science, a theory is:

a. an untested hypothesis.

b. a general set of principles, supported by evidence, that explains some aspect of the natural world.

c. speculation about the natural world, based on general knowledge of a field.

d. an observation.

e. the first idea proposed to explain some aspect of the natural world.

Which of the following are central ideas in the theory of evolution by natural selection? (List all that apply.)

a. Organisms vary in traits that affect their reproduction.

b. Descent with modification occurs over generations.

c. Evolution has a goal.

d. Traits that confer a reproductive advantage will become more common in populations over time.

e. Traits that are acquired during the life of an individual contribute to evolution.