One important feature of modern classification systems is that they a. can predict the discovery of new species. b. apply only to organisms that are alive today. c. group organisms that live in the same habitat. d. can incorporate new scientific discoveries.

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.