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?
A) reduced hybrid viability B) hybrid breakdown C) reduced hybrid fertility D) gametic isolation
Which of the following statements best describes a limitation of the biological species concept?
A) The biological species concept cannot be applied to fossils because the biological species concept uses reproductive isolation to define species. B) The biological species concept cannot be applied to haploid species because the biological species concept delineates species by the presence of gene flow between species. C) The biological species concept cannot be applied to polyploid species because the biological species concept separates species by the absence of gene flow between them. D) The biological species concept cannot be applied to sexual species because the biological species concept separates species by the absence of gene flow between species.
Two populations of birds with somewhat different coloration live on opposite sides of a peninsula. The habitat between the populations is not suitable for these birds. When birds from the two populations are brought together in captivity, they interbreed and produce fertile young whose appearance is intermediate between the two parents. In the wild, the two populations remain separate as a result of which of the following factors?
A) temporal reproductive isolation B) lack of hybrid viability C) behavior isolates reproductive activities D) habitat isolation