Read the selection from the section "Vestigial Structures." These are leftovers from an earlier form of the species before it changed. Over time, a species can collect several adaptations that eventually render a particular structure useless, however, this structure does not completely disappear.

According to social exchange theory, altruistic behaviors benefit the individual who performs them.

Complete the sentence to describe the law of conservation of energy. the law of conservation of energy states that energy cannot be created or , but it can be

The graph represents the distance a car travels over time while on the highway. which statement about the car's trip is accurate? a) the car does not move over time. b) the car travels at a constant velocity. c) the car's velocity increases constantly over time. d) the car's velocity decreases constantly over time.