Exam 6: Evolution and Ecology

Refer to the table. - Suppose that, following the experiments by Dodd, Drosophila pseudoobscura are fed one of two diets (starch or maltose) for many generations. Once they have adapted to the new food sources, individual females from the starch treatment are given a choice between a male adapted to starch (a starch male), or a male adapted to maltose (a maltose male). When 50 females have chosen a mate, the experiment is repeated with females adapted to maltose. The results are in the table. Which conclusion is best supported by the data?

Refer to the figure. Eurosta flies parasitize goldenrod plants, causing the plant to produce a gall in which the fly larva matures as it feeds on the plant. The larvae within the galls are parasitized by tiny wasps, which tend to parasitize the smallest galls, and are also fed on by Downy woodpeckers, which tend to feed on the largest galls. The figure shows the size distribution of galls before and after both wasps and woodpeckers have impacted their survival. This is an example of

Refer to the figure. -You are studying a remote island before and after a volcanic eruption. Data at Time 1 were collected one month before the eruption, and data at Time 2 were collected one month after the eruption. All of the species on the island are endemic. The island is 100 km across. Each animal icon represents 20 individuals. Species A and B (the two snail species) generally move a distance of only 2 m a day. Species C (the bird) often covers 20 km a day in search of food. After the eruption, the lava flow hardens, and the island is divided by a 20-km strip of bare rock with few, if any, resources these animals need to survive. Would you expect to see a change in patterns of gene flow in species B and C? Why or why not?

Refer to the figure. - The figure shows the frequency of the Adh^s allele at different latitudes in Australia taken in 1979?1982, and again in 2002?2004. Consider the 1979?1982 data. On a per-degree-of-latitude basis, the frequency of the Adh^s allele _______ by approximately _______ as one goes north.

Refer to the figure. -The figure shows four cases of selection on egg number in a population of flour beetles. The solid blue line represents the frequency of the original population and the dashed red line represents the frequency distribution after eight generations. Which figure most likely represents a case of stabilizing selection?

Refer to the figure. - Consider the three most dramatic mass extinctions in Earth's history. If a fourth major mass extinction occurred after the same interval as the previous ones, around how many million years from now would you predict it would occur?

Refer to the figure. You are studying the evolution of a group of tree species that all share a common ancestor. -Referring to the figure, which two species are most closely related? What evidence do you have to support this?

Which of the following has resulted from commercial fishing for cod?

Refer to the table. - Suppose that, following the experiments by Dodd, Drosophila pseudoobscura are fed one of two diets (starch or maltose) for many generations. Once they have adapted to the new food sources, individual females from the starch treatment are given a choice between a male adapted to starch (a starch male), or a male adapted to maltose (a maltose male). When 50 females have chosen a mate, the experiment is repeated with females adapted to maltose. According to the results in the table, what percentage of maltose females chose starch males?

If a population of Silene (a plant) has 400 members with 180 of genotype DD, 180 of genotype Dd, and 40 of genotype dd, the frequency of the D allele is

Refer to the figure. -You are studying a remote island before and after a volcanic eruption. Data at Time 1 were collected one month before the eruption, and data at Time 2 were collected one month after the eruption. All of the species on the island are endemic. The island is 100 km across. Each animal icon represents 20 individuals. Species A and B (the two snail species) generally move a distance of only 2 m a day. Species C (the bird) often covers 20 km a day in search of food. After the eruption, the lava flow hardens, and the island is divided by a 20-km strip of bare rock with few if any resources these animals need to survive. Based on your knowledge of gene flow, genetic drift, and speciation, what do you predict will happen to these species over time? Do you predict that the current species will remain the same species or do you think they might split? How would you determine whether a species had split into two new species?

Which evolutionary process is most likely to inhibit speciation?

Suppose a genie offers you a trip in a time machine, and you and a paleontologist go back 800 million years in Earth's history. Assuming you have all the appropriate tools to detect life, what should you expect to see?

Suppose a population of worms is variable at a genetic locus involved in foraging behavior. There are just two alleles at this locus, F and f. Individuals that are FF or Ff are rovers and will travel widely in pursuit of food. Individuals that are ff are sitters and will not travel as far. The frequency of the F allele is 0.75. The frequency of the f allele is _______ and, assuming the Hardy-Weinberg equation, the percentage of the population that are sitters is therefore _______.

Which statement about mass extinctions is false?

Suppose that several flies of a population that previously fed on blueberries start to feed on honeysuckle. Due to genetic differences that accumulate as the flies adapt to feeding on honeysuckle, these "honeysuckle" flies eventually breed earlier than the ancestral flies. This change most likely represents an early stage of speciation brought about by

Which of the following describes the process in which some individuals have heritable phenotypic traits that give them an advantage in either survival or reproduction?

The mutation rate of a gene involved in lactose metabolism is two mutations per million copies of the gene per generation. Suppose there are 15 million individuals in a population of a yeast, each with two copies of this gene (i.e., they are diploid). In this yeast population, how many new mutations would we expect at this gene each generation?

The most recent mass extinction, which wiped out the dinosaurs, occurred approximately _______ million years ago.

Which statement about genetic drift is false?