This diagram shows the homologous structures in humans, horses, dolphins and bats. what do these homologous structures suggest about the ancestry of these four organisms?
a. the four organisms are the same species.
b. the fours organisms are the same size.
c. the four organisms share a common ancestry.
d. the four organisms have similar patterns of locomotion.

The images show two species of tree frogs in a particular region. the gray tree frogs are adapted to the trees of the woodlands, while the green tree frogs can survive in woodlands or grasslands. the gray frog was abundant in the woodlands. because of climatic changes, most of the trees in the region died, and the woodlands changed to grasslands. in such a case, the . the gray tree frog is closely related to the green tree frog genetically, but they have different mating calls. this suggests that speciation occurred because of .