Primary succession occurs when pioneer species move into an area that has no plants. Which organisms are common pioneer species?
A.
Conifer trees and tall grasses with roots that loosen the soil
B.
Mosses and lichens that can grow on rocky surfaces
C.
Grasses and weeds that arrive as seeds carried by the wind and then germinate in rich soil
D
Vines and shrubs that help prevent the erosion of shallow soil

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.