Exam 14: The Origin of Species

Frequently,a group of related species will each have a unique courtship ritual that must be performed correctly for both partners to be willing to mate.Such a ritual constitutes a _, reproductive barrier.

In their 30- year studies of Darwin's finches,the Grants have discovered that while the medium ground finch and cactus finch occasionally form hybrids,these hybrids

Which butterfly has changed gradually but significantly from its ancestor through microevolutionary events that were not part of a speciation event?

Ancestral diploid wheat species had 2n = 14 chromosomes.What happened when two of these species hybridized?

Which of the following types of reproductive barriers separates a pair of species that could interbreed except that one mates at dusk and the other at dawn?

The emergence of a new plant species over a brief period of time,followed by a long period of little change,is consistent with which of the following theories?

Which of the following would a biologist describe as microevolution?

When plants undergo allopatric speciation,an initial reproductive barrier is often

The suggests that speciation occurs in brief spurts.

Uplift and formation of a mountain range divides a freshwater snail species into two isolated populations.Erosion eventually lowers the mountain range and brings the two populations together again,but when they mate,the resulting hybrids all produce sterile young.This scenario is an example of

The fossil record shows that for many plant and animal groups,the time between speciation events

One of the key contributions of the punctuated equilibrium model is that it helps explain

Which of the following descriptions best represents the gradual model of speciation?

Which of the following types of reproductive barriers separates a pair of insect species that could interbreed except that one lives on goldenrod plants and the other on autumn daisies in the same general area?

The biological species concept is

In a hybrid zone,can occur if the reproductive barrier between two species is weak,as seen among cichlids in the murky waters of modern Lake Victoria.

Under the biological species concept,a species is a group of organisms that

Which of the following statements about the Galápagos finches is false?

Two species that sometimes mate and produce vigorous but sterile offspring are separated by

Diane Dodd's experiments using fruit flies demonstrated that