Problem 1
Birds living on oceanic islands tend to have a smaller clutch size than the same species (or close relatives) breeding on the mainland (Klomp \(1970,\) p. 85 ). Explain this on the basis of Lack's hypothesis.
Problem 2
Cane toads have been introduced to Australia and many of the Pacific islands. Their skin contains glands that secrete poisons that are toxic to most vertebrates. Discuss how evolution might operate on potential predators of cane toads in areas like Australia in which the predators have no prior evolutionary history of interactions with these toads. Phillips and Shine (2006) discuss this issue.
Problem 3
Ladybird beetles are distasteful to predators because of toxic chemicals they secrete, yet they also have dark melanic forms (Majerus \(1998,\) p. 221 ). Melanic ladybirds have declined in frequency in central England along with the peppered moth during the past 50 years as air quality has improved. If ladybirds are not eaten by predators, how might you explain these changes in melanic frequency?
Problem 5
Royama \((1970, \mathrm{pp} .641-642)\) states: Natural selection favors those individuals in a population with the most efficient reproductive capacity (in terms of the number of offspring contributed to the next generation), which means that the present-day generations consist of those individuals with the highest level of reproduction possible in their environment. Is this correct? Discuss.
Problem 6
In many temperate zone birds, those individuals that breed earlier in the season have higher reproductive success than those that breed later in the season. If climate change is making spring weather occur at earlier dates, will this lead to directional selection for earlier breeding dates in these birds? What constraints might affect this type of directional selection?
Problem 7
Some birds such as grouse and geese have young that are mobile and able to feed themselves at hatching (precocial chicks). Discuss which factors might limit clutch size in these bird species. Winkler and Walters (1983) have reviewed studies on clutch size in precocial birds.
Problem 8
In arctic ground squirrels, adult females are more likely to give alarm calls than adult males. If alarm calls are favored by kin selection, why might this difference occur? Could alarm calls be explained by group selection? Why or why not?
Problem 11
Discuss how the concept of time applies to evolutionary changes and to ecological situations. Do ecological time and evolutionary time ever correspond?
Problem 12
A hypothetical population of frogs consists of 50 individuals in each of two ponds. In one pond, all of the individuals are green; in the other pond, half are green and half are brown. During a drought, the first pond dries up, and all the frogs in it die. In the population as a whole, the frequency of the brown phenotype has gone from 25 percent to 50 percent. Has evolution occurred? Has there been natural selection for the brown color morph?
