7. the diagram illustrates the differences between the skulls and brain volumes of three extinct hominins. in each drawing in the diagram, the shaded area inside the skull indicates the size of the brain. based on the relative size of the brain, which species is capable of more complex behavior, such as the use of tools? a. australopithecus africanus b. all three species were capable of equivalent complex behaviors. c. homo erectus d. homo neanderthalensis