As part of a research project, a student compares two specific regions, one a desert biome and the other a temperate forest. The desert has very little plant life other than cacti and several hearty weeds and is inhabited by animals such as insects, lizards, and small rodents. The temperate forest has a great deal of plant life, including a variety of trees and grasses, and is home to animals such as rabbits, deer, elk, and wolves. Because the animals in the temperate forest region are on average much larger than those in the desert, the student theorizes that more massive species of animals prefer cooler climates.

Using your knowledge of biology: discuss the validity of the student's theory; and present an alternative theory that is consistent with the principles of energy pyramids and food webs