Exam 17: Speciation

An evolutionary biologist who makes decisions about whether to consider different populations of lacewings as separate species based on observations of the individuals with which these lacewings will mate is most likely employing the _______ species concept.

Use the following to answer questions : Two species of crickets have partially overlapping ranges.Hybrids are never found in the areas where the species meet.Individuals taken either from areas where they meet or areas where they do not meet will rarely mate in the lab because the females reject the songs sung by males of the other species.Of the few hybrids that are produced in lab crosses,all have low viability. -The two cricket species exhibit _______ isolation.

Which statement about the Dobzhansky-Muller model of speciation is false?

Despite inhabiting overlapping ranges,the western spotted skunk and the eastern spotted skunk do not interbreed,partly because the western species breeds in early fall and the eastern species breeds in late winter to early spring.This is an example of _______ isolation.

Which condition is least likely to lead to allopatric speciation?

Even trained biologists have difficulty telling females of Drosophila melanogaster and D.sechellia apart,and yet these species are reproductively isolated.Thus,these species are considered _______ species.

Two species of monkeyflowers have diverged in the structure of their flowers such that they can no longer be effectively pollinated by the same pollinator species.This is an example of _______ isolation.

Refer to the diagram below showing different species of Bombina toads occupying different regions of Europe.A small area of overlap between these regions constitutes a hybrid zone.If individuals from differing populations overcome prezygotic reproductive barriers,additional postzygotic barriers may prevent the formation of stable hybrids.Based on the data shown below,which statement is true?

What is an advantage that a lineage species concept has over the biological species concept?

The biological species concept does not apply to which group of organisms?

Phylogenetic information is most useful for _______ species concept.

Self-fertilization is common in many plant species but less common in animals.One consequence of this difference is that

The Isthmus of Panama cut off gene flow between Atlantic and Pacific populations of a species of fish.The cessation of gene flow led to the accumulation of genetic differences between the populations,which led to reproductive isolation.Now Atlantic and Pacific populations of this fish are separate species,and even if they were again to come into contact with each other,they could not interbreed.This situation illustrates the phenomenon of

Which factor is most likely to yield narrow hybrid zones?

Which statement about species concepts is true?

A hybrid zone that has formed recently

Which condition is least likely to lead to geographic isolation and allopatric speciation?

Which statement about the hybrid zone between species of the European Bombina toad is false?

Which mode of speciation is believed to be the dominant one among most groups of organisms?

Which situation would pose a major difficulty for applying the biological species concept?