Genetic and environmental factors affect which traits are passed on from parent to offspring over generations and how they are passed on. Favorable traits for a given environment are passed on from parent to offspring. Unfavorable traits are selected against and inherited less frequently over time because they do not promote survival and reproduction.

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 .