Bird guides once listed the myrtle warbler and Audubon's warbler as distinct species.Recently,these birds have been reclassified as eastern and western forms of a single species,the yellow-rumped warbler.Which of the following pieces of evidence,if true,would be cause for this reclassification?
A)The two forms interbreed often in nature,and their offspring survive and reproduce well.
B)The two forms live in similar habitats and have similar food requirements.
C)The two forms have many genes in common.
D)The two forms are very similar in coloration.

Question

Quizplus · Accepted Answer

The fact that the two forms interbreed often and produce viable offspring suggests that they are not genetically distinct enough to be considered separate species. This is strong evidence for reclassifying them as forms of a single species. The other choices do not necessarily provide such strong evidence for reclassification.

Bird Guides Once Listed the Myrtle Warbler and Audubon's Warbler