Exam 13: The Origin of Species

Many butterflies in the genus Heliconius are mimetic, which means that they closely mimic the wing patterning and color of highly poisonous species even though they themselves are not poisonous. This is a benefit because many predators (such as birds) learn to avoid poisonous species by identifying their wing patterns and colors. Some closely related Heliconius species mimic different poisonous species. Although they can successfully hybridize and produce viable/fertile offspring that have high fitness in the laboratory, the hybrids are intermediate in wing patterning and color and are not good mimics. Consequently, they have low fitness in nature. This is an example of

Which statement regarding the parasitoid wasps that infect the cryptic skipper species of Costa Rican butterflies is true?

In the monkeyflowers studied by Bradshaw and Schemske, reproductive isolation results from

Species A has chromosome number 2n = 18, and species B has chromosome number 2n = 20. The two plants hybridize and produce viable offspring through allopolyploidy. What is the chromosome number of the viable offspring?

Which of the following is a barrier to gene flow that occurs before mating occurs?

About what percentage of genes are essential for all strains of Escherichia coli?

The ________ species concept cannot be used to define bacteria and archaea because organisms in these domains reproduce ________.

What reproductive isolating mechanism has led to speciation of palms on Lord Howe Island?

Which of the following is true regarding "magic traits"?

Which of the following would provide evidence for reinforcement?

A geographic barrier that only partially isolates two populations, so that gene flow is reduced but not eliminated, may lead to

Which species concept(s) focus(es) on the evolutionary history of populations?

An allele is experiencing positive selection when

The stable ecotype model is useful because

Why is it unusual for one species of caterpillar to feed on a wide range of plants?

What does the phylogeny of swordtail cricket species in Hawaii reveal about speciation?

Discuss the definition of a bacterial species. You should include at least two species concepts that best characterize bacteria, explain what is important to take into account when defining bacteria, and explain the difficulties of the definition.

Is the fact that many plant species are capable of self-fertilization is important in understanding why polyploid speciation is more common in plants than in animals? Explain why or why not.

Extrinsic postzygotic isolation is most likely when

A pair of insect species inhabits the same community, but one lives on goldenrod plants and the other on autumn daisies and rarely leave their preferred type of plant. This is an example of ________ isolation, which is a ________ barrier to gene flow