Read each example and decide what the resulting effect on the gene pool of that population would be. x A zebra migrates to join a different herd of zebras.
Competition for sunlight leads to taller trees.
The DNA of a snake changes to make its venom stronger.
and kills most of the animals.
A grassfire randomly sweeps through a population of buffalo

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 .