Which is the best definition of directional selection? - a process by which two species can no longer reproduce

- a process by which one of the extreme variations of a trait is favored

- a process by which individuals with either extreme of a trait are favored

- a process by which average individuals in a population are favored

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.