A species of ground squirrel is found in many areas of the United States along the eastern side of the Rocky Mountains. One population, however, is found to the west of the Rockies. What scientific evidence would support the vicariance hypothesis explaining their distribution?

MCQs on the evolutionary history, phylogenetic relationships, comparative anatomy and physiology, and ecological interrelationships among animal taxa, as well as the evolutionary pressures that led to physiological and ecological differences among species and groups.