Unit 7 Evolution Review

In Darwin's thinking, the more closely related two different organisms are, the

• more similar their habitats are.

• less similar their DNA sequences are.

• more recently they shared a common ancestor.

• less likely they are to have the same genes in common.

• more similar they are in size.

During drought years on the Galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. If a drought persists for several years, what should one expect to result from natural selection?

• Small birds gaining larger beaks by exercising their mouth parts.

• Small birds mutating their beak genes with the result that later-generation offspring have larger beaks.

• Small birds anticipating the long drought and eating more to gain weight and, consequently, growing larger beaks.

• More small-beaked birds dying than larger-beaked birds. The offspring produced in subsequent generations have a higher percentage of birds with large beaks.

• Larger birds eating less so smaller birds can survive.

Structures as different as human arms, bat wings, and dolphin flippers contain many of the same bones, these bones having developed from very similar embryonic tissues. How do biologists interpret these similarities?

• By identifying the bones as being analogous

• By the principle of convergent evolution

• By proposing that humans, bats, and dolphins share a common ancestor

• By looking at where the animals live

When we say that an individual organism has a greater fitness than another individual, we specifically mean that the organism

• lives longer than others of its species.

• competes for resources more successfully than others of its species.

• mates more frequently than others of its species.

• utilizes resources more efficiently than other species occupying similar niches.

• leaves more viable offspring than others of its species.

Which describes an African butterfly species that exists in two strikingly different color patterns?

• artificial selection

• directional selection

• stabilizing selection

• disruptive selection

• sexual selection

Fossil evidence indicates that horses have gradually increased in size over geologic time. Which of the following terms best describes this?

• artificial selection

• directional selection

• stabilizing selection

• disruptive selection

• sexual selection

Most Swiss starlings produce four to five eggs in each clutch. Those producing fewer or more than this have reduced fitness. Which of the following terms best describes this?

• artificial selection

• directional selection

• stabilizing selection

• disruptive selection

• sexual selection

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian islands have different elaborate courtship rituals that involve fighting other males and stylized movements that attract females. What type of reproductive isolation does this represent?

• habitat isolation

• temporal isolation

• behavioral isolation

• gametic isolation

• postzygotic barriers

All of the following are examples of events that can prevent breeding between species EXCEPT:

• The potential mates experience geographical isolation.

• The potential mates experience behavioral isolation.

• The potential mates have different courtship rituals.

• The potential mates have similar breeding seasons.

• The gametes of potential mates have biochemical differences.

Homologous structures are often cited as evidence for evolution. All of the following are examples of homologous structures EXCEPT

• the wings of a bird and with wings of a bat

• the flippers of a whale and the arms of a man

• the pectoral fins of a porpoise and the flippers of a seal

• the forelegs of an insect and the forelimbs of a dog

• the hind legs of a lizard and the legs of a chicken.