Final answer:
Natural selection can shape both the brain and behaviors by favoring traits that increase an organism's fitness. This includes traits related to brain function and behaviors that enhance survival and reproduction.
Step-by-step explanation:
Natural selection can shape both the brain and behaviors. Natural selection acts on genetic variations in a population, favoring traits that increase an organism's fitness or ability to survive and reproduce. This includes traits related to brain function and behaviors that enhance an organism's chances of survival and reproduction. For example, if a certain behavior allows an organism to better find food or avoid predators, individuals with that behavior are more likely to survive and pass on their genes, leading to the shaping of both the brain and behaviors through natural selection.