22. Evolution of Populations

Which of the following mechanisms can form entirely new alleles?

Sexual recombination includes the shuffling of chromosomes in __________ and fertilization.

Which type of mutation plays the most important role in increasing the number of genes in the gene pool?

What is the importance of neutral variation in evolution?

__________ and __________ generate variation, whereas __________ results in an adaptation to the environment.

A population of 15 birds inhabits a fairly new island. Ten of the birds are dark brown, and five of them are light brown. By chance, two of the dark brown birds and three of the light brown birds die before producing any offspring. All of the birds in the next generation are dark brown. This change in phenotypic frequency can be attributed to __________.

An earthquake hits a small island. All but a small group of closely related lizards are eliminated, and the survivors spread out over the island. This is an instance of __________.

Which of the following scenarios would most likely result in the microevolution of a population of humans?

Which of the following is the best example of gene flow?

Which of the following most accurately measures an organism's fitness?

The lethal genetic disorder Tay-Sachs disease occurs in individuals with two copies of a recessive allele of the responsible gene. Which of the following statements is true?

Antibiotic resistance in bacteria is an example of which of the following?

For several years, scientists have warned doctors of the danger of overprescribing antibiotics such as penicillin. Scientists are concerned because __________.

A population of squirrels is preyed on by small hawks. The smaller squirrels can escape into burrows. The larger squirrels can fight off the hawks. After several generations, the squirrels in the area tend to be very small or very large. What process is responsible for this outcome?

Birds with average-size wings survived a severe storm more successfully than other birds in the same population with longer or shorter wings. If severe storms occur regularly, then over time, one should expect these storms to bring about __________.