Traits that are derived from a common ancestor, like the bones of human arms and bird wings, are said to be               .

Which of the following observations is not part of the theory of natural selection?

a. Populations of organisms have more offspring than will survive

b. There is variation among individuals in a population

c. Modern organisms are unrelated

d. Traits can be passed on from parent to offspring

e. Some variants in a population have a higher probability of survival and reproduction than other variants do

Within six months of effectively using methicillin to treat S. aureus infections in a community, all new S. aureus infections were caused by MRSA. How can this best be explained?

a. A patient must have become infected with MRSA from another community.

b. In response to the drug, S. aureus began making drug- resistant versions of the protein targeted by the drug.

c. Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency.

d. S. aureus evolved to resist vaccines.

Which of the following did not influence Darwin as he synthesized the theory of evolution by natural selection?

a. Examples of artificial selection that produce large and relatively rapid changes in domesticated species.

b. Lyell's Principles of Geology, on gradual geologic changes.

c. Comparisons of fossils with living organisms.

d. Mendel's paper describing the laws of inheritance.

What holds cellulose molecules together in bundles large enough to form fibers?

a. The cell wall

b. Peptide bonds

c. Hydrogen bonds

d. Hydrophobic interactions

The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?

a. Forelimb evolution was adaptive in people and bats, but not in whales.

b. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.

c. Genes mutate faster in whales than in humans or bats.

d. Whales are not properly classified as mammals.

Natural selection is sometimes described as 'survival of the fittest.' Which of the following best measures an organism's fitness?

a. How many fertile offspring it produces

b. How strong it is when pitted against others of its species

c. Its ability to withstand environmental extremes

d. How much food it is able to make or obtain

How can evolutionary fitness be measured? Select True or False for each statement.

T/F Document how long individuals survive.

T/F Count the number of healthy, fertile offspring produced.

T/F Determine which individuals are strongest.

T/F Determine which phenotype is the most common.