23. Speciation

When gene flow between two populations ceases, the potential for __________ exists.

Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species that lived side by side in parts of their ranges. However, recent books show them as eastern and western forms of a single species, the yellow-rumped warbler. Apparently, the myrtle warbler and Audubon's warbler __________.

Imagine that part of a population of South American finches is blown by a storm onto an island far offshore and manages to survive and reproduce there for a period of 10,000 years. After that period, a climate change results in lower sea levels and the reconnection of the island with the mainland. Members of the formerly isolated island finch population can now interact freely with members of the original mainland population. Which of the following observations would, by itself, lead you to conclude unequivocally that the island finch population had evolved into a distinct species, according to the biological species concept?

At which point in the adaptation of a population is it clear that speciation has occurred?

Define 'biological species.'

Name the two types of speciation represented by this diagram. For each type, describe how reproductive barriers may develop between the new species.

What distinguishes a morphospecies?a. It has distinctive characteristics, such as size, shape, or coloration.b. It represents a distinct branch in a phylogeny of populations.c. It is reproductively isolated from other species.d. It is a fossil from a distinct time in Earth history.

Males of different species of the fruit fly Drosophila that live in the same parts of the Hawaiian Islands have different elaborate courtship rituals. These rituals involve fighting other males and making stylized movements that attract females. What type of reproductive isolation does this represent?a. habitat isolationb. temporal isolationc. behavioral isolationd. gametic isolation