Exam 17: The Origin of Species

Interbreeding two different species of lovebirds produces offspring that are unable to build a nest after they mature because they lack the appropriate nest- building behavior needed to build a nest. This limits genetic mixing between the species due to

Which species is least likely to become extinct?

Since the Pleistocene ice age, deserts have been gradually forming in the southwestern United States. As the original lakes and rivers of this area shrank into isolated streams, ponds, and springs, the fishes living in them developed a strong potential for

A single species of finch from South America was displaced to a new habitat in the Galápagos Islands and evolved rapidly into several new species as it exploited the new resources. What occurred in these Darwin's finches?

A flower has four copies of each chromosome. This is an example of .

The Kaibab squirrel lives on the north side of the Grand Canyon, and the Abert squirrel lives on the south side. Even though these two populations are only miles apart, their gene pools are kept isolated by

Two populations of plants look identical but their flowers are fertilized by different pollinators- one by a night- flying hummingbird moth, the other by honeybees. These two populations of flowers are examples of

Two species of plants that both use honeybees as pollinators but reproduce at different times of the year- one spring, the other midsummer- demonstrate geographic isolation.

One method of maintaining the genetic isolation of a population is the inability of sperm to fertilize eggs of a different species. This is called

When the pollen of one plant species will not germinate on the flower of another species, it is an example of

Hybridization of two species in which of the following cases could lead to the extinction of one of the original species?

Organisms from two separate species can look anatomically similar.

Which statement best describes the reproductive isolation between populations of Rhagoletis flies, one of which is found on apple trees and the other that is found on hawthorn trees?

Populations that were once considered separate species are sometimes reassigned to the same species because

Hybrid inviability occurs when two species mate and produce fertile offspring.

A pet store puts both Norway rats (Rattus norvegicus) and black rats (Rattus rattus) in the same cage. If mating occurs, the pregnancy will not succeed because the embryos fail to develop properly. This is an example of

Overspecialized adaptations

Polyploidy is an important mechanism of speciation in plants.

Modern biologists have identified two main factors that drive speciation. What are these factors?

What events can push a species to extinction?