Exam 19: The Origin of Species

Which statements about the Lake Victoria cichlid fishes are true? Check all that apply.

Several new tetraploid species of plant known as the salsifies have arisen in western North America. These new species arose from diploid species that went through the process of allopolyploidy. This mode of speciation is known as ________ and it occurs _______.

Studies of snapping shrimp on either side of the Isthmus of Panama have shown that each Caribbean shrimp species is more closely related to a Pacific shrimp species than it is to any other Caribbean shrimp species. The most likely explanation for this result is

Adaptive radiation is best described as the

Two hundred years ago, the fly species Rhagoletis pomonella only laid its eggs on fruit of the hawthorn tree. Today, different "host races" of R. pomonella lay their eggs on hawthorns OR apples. Apples occur within the range of hawthorns, so divergence between apple flies and hawthorn flies could be the first step in sympatric speciation. Choose the evidence that supports that R. pomonella is undergoing sympatric speciation. Check all that apply.

Lake Victoria is famous for its variety of cichlid fishes. In fact, they offer the most diverse assembly of vertebrates presently known to science. One trait that scientists have focused on as one possible reason for their adaptability is

NASA Scientists send a small population of dogs to a new planet in order to test if it will be hospitable for human colonization. Through a random lottery, only Great Dane and St. Bernard dog breeds are sent, and the resulting population consists of tall, longhaired dogs. After 100 years these dogs return to earth and are no longer able to mate with earth dogs. This scenario is an example of

Indicate which examples would be considered different species under the Biological Species Concept. Check all that apply.

Two species regularly come into contact and form hybrids that have higher fitness than either of the parental species. What are the possible consequences of regular hybridization between these species? Check all that apply.

Which statements about the adaptive radiation of New Zealand alpine buttercups are true? Check all that apply.

A virgin pine forest covers a valley, and one of the inhabitants is a red squirrel species. A large volcanic eruption occurs and separates the valley with a huge lava flow that the squirrels cannot cross, thus producing two isolated populations of squirrels. What change needs to occur for the two populations of squirrels to become separate species?

Scientists estimate that as much as one-fourth of all species will become extinct in the near future, a rate of extinction not seen on Earth since the Cretaceous mass extinction. How are humans contributing to this mass extinction? (Check all that apply)

Scientists studying a group of related bird species on an island archipelago discover that these species are always more closely related to each other within an island than they are between any two islands. The most likely explanation for this result is that

The most famous and well-studied mass extinction occurred at the end of the Cretaceous period (65 million years ago), at which time the dinosaurs and a variety of other terrestrial and aquatic organisms went extinct. Recent findings have supported the hypothesis that this extinction event was triggered when a large asteroid slammed into Earth. Which of the following could cause a global mass extinction following an asteroid strike? (Check all that apply)

Reproductive isolation is ______ by natural selection to lead to speciation.

Scientists found that different beak shapes lead to different mating songs in Darwin's finches. This result best supports which hypothesis?

Which statements about gradualism and punctuated equilibrium are true? Check all that apply.

Scientists investigating speciation in fruit flies divided a single population of flies into separate populations that each lived in their own cage on one of two food sources: maltose-based food or starch-based food. After several generations, the flies' mate preference was tested, and it was found that flies strongly preferred to mate with other flies that were raised on the same food source. This results suggests that