When Arizona's Grand Canyon formed, squirrels and other small mammals that had once been part of a single population could no longer contact and reproduce with each other across this new geographic barrier. They could no longer interbreed. On the other hand, birds and other species that could easily cross this barrier continued to interbreed. Predict the long-term effect the formation of the Grand Canyon may have had on squirrel and bird species over time. *

What pattern has been observed between humans moving to a new area and extinction?

The endangered Amargosa River pupfish (Cyprinodon nevadensis amargosae) lives in Death Valley, where different populations of the species live in total isolation from one another in tiny permanent pools and short stream segments (Lema and Nevitt 2004). Although these populations have been separated from one another for only 400 to 4000 years, males in some places aggressively defend territories and court females drawn to them, while males in other populations are not aggressive toward one another and do not defend territories. How could these changes occur so rapidly? How might you establish experimentally that the hormone arginine vasotocin (AVT) decreases aggressive behavior in pupfish? If the hormone does lower aggression in this species, what predictions could you make about AVT or about AVT receptor protein differences between territorial and nonterritorial males of the same species? please don't write from any online source

Male frogs commonly attract females of the same species using a unique, species-specific call (or "song"). Mónica, an ecologist, notices that there are two closely-related species of frogs living in the pond in her backyard. However, these species never interbreed because it appears that females are only attracted to the call of their own species. This is an example of _________________.   a. Ecological isolation   b. Hybrid inviability   c. Gametic isolation   d. Transpecies isolation   e. Behavioral isolation