1. Why is biodiversity important to ecosystem? A. It decrease the number of species in a given ecosystem.
B. It helps populations adapt to changes in the environment.
C. It permits animals to feed in a specific area.
D. It increases the level of the food chain.

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.