Kangaroo rats, kangaroo mice, and pocket mice are found only in the deserts of the Southwestern United States. They share a numb
er of features, including external, fur-lined cheek pouches, which they use to gather and transport seeds to their burrows. But they are also quite different from one another in size, overall shape, behavior, and other features. The best explanation for their similarities and differences is that A. the species are not closely related evolutionarily and that any similarity is due to the fact that they live in similar environments. B. the desert environment forced each species to develop traits allowing it to survive and reproduce. Each species represents a different way in which a small mammal can survive and reproduce in the desert. C. the species share a common ancestor (one that had, among other traits, external fur-lined cheek pouches), and natural selection has resulted in each having specific adaptations for its own environment. D. natural selection has resulted in each species having specific adaptations to its own environment, but the species do not share a common ancestor. E. None of the above.
C. the species share a common ancestor (one that had, among other traits, external fur-lined cheek pouches), and natural selection has resulted in each having specific adaptations for its own environment.
Explanation:
The best explanation for their similarities and differences is that kangaroo rats, kangaroo mice, and pocket mice must have evolved from a common seed-eating ancestor that has eternal, fur-lined cheek pouches, which serve as structures for gathering and transporting of grains. We can infer that: evolutionary change by natural selection, as a result of change in environmental conditions, brought about divergence as several species evolved differently in response to their changing environment. Thus, different features were developed by each species to make them better adapted to their environment.
The answer is B. Geology has shown a thin layer of iridium (a rare mineral on earth but found on asteroids and meteors) in the rock layers between the Cretaceous and Paleogene periods. Below this layer are numerous fossils of pterosaurs and dinosaurs, but above the layer are drastically few. The aftermath of asteroid impact is believed to have smothered most vegetation from earth which dinosaurs depended on as a source of food.
