Chapter 24 Reading Quiz

Which of the following factors is the primary criterion for determining species boundaries when applying the biological species concept?

Gene flow

Three populations of crickets look very similar, but the males have different courtship songs. If the cricket populations were to contact each other in the wild, the different courtship songs would most likely function as which type of reproductive isolating mechanism?

behavioral

Which of the following possible causes of speciation is most likely to cause rapid speciation?

polyploidy

Two species of frogs belonging to the same genus occasionally mate, but the embryos stop developing after a day and then die. Which of the following mechanisms keep the species separate?

reduced hybrid viability

Which of the following statements best describes the difference between geographic isolation and habitat differentiation (isolation)?

relative location of two populations as speciation occurs

If biological species are defined in terms of reproductive compatibility, which of the following factors determines the formation of a new species?

reproductive isolation

Which of the following organisms would be LEAST able to cross a geographic barrier of water that could lead to allopatric speciation?

small rodents

Which of the following outcomes is most likely in hybrid zones where reinforcement of isolating mechanisms is occurring?

speciation

According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that ________.

speciation occurred rapidly in geologic time

Which of the following provides an example of a mechanical isolation as a prezygotic barrier?

two snails have shells that spiral in different directions

Which of the following statements correctly describes a change that must occur for a new species to arise?

At least one gene, affecting one reproductive barrier, must change.

A narrow hybrid zone separates the toad species Bombina bombina and B. variegata. A genetic study identified a locus where one allele (R) occurred in all B. variegata, occurred in a few B. bombina at the edge of the hybrid zone, and was replaced totally by another allele (r) in B. bombina that lived far from the hybrid zone. Which of the following statements is most likely to be accurate with regard to the frequency of V1 in the hybrid zone?

The frequency of R declines in hybrids as animals are sampled closer to the range of B. bombina

Some geographic areas contain two closely related species of birds (sympatry), while other areas contain only one of the species (allopatry). Males from allopatric populations look very similar to each other, but males in the sympatric populations look different from each other and from both allopatric types of males. Which of the following outcomes is most likely if a female in a sympatric area is courted by a male that migrated into the area from an allopatric area?

The female is less likely to mate with the immigrant than with a male native to the area

New species can sometimes arise via hybridization and subsequent polyploidy. Which of the following describes the likely geographic and reproductive relationships between the hybridizing species?

The two species are sympatric and breed during the same seasons of the year