Which source of energy is the most important in driving the water cycle? A. Geothermal energy changes water to steam so condensation can occur. B. Wind helps change surface water into water vapor during the process of evaporation. C. Gravity is necessary to pull water downhill when it rains, thus allowing water to flow into rivers and streams. D. The Sun heats up Earth's surface water creating the process of evaporation.

Which of the following best describes the expensive tissue hypothesis? brains require more energy, so the gut had to be reduced, and larger brains and tool use led to higher quality diets. increasing body size means that homo neanderthalensis had to include more fat in its diet. brains require more energy, so the gut had to be reduced as brains got bigger. brains require more fat, so the gastrointestinal viscera (gut) had to expand, and hands were needed to acquire more food.