Brain endocasts of Australopithecus africanus (purple; over 3 million years old), Homo erectus (specimen KNM-ER 42700, green, approx. 1.55 million years old), Homo naledi (turquoise, approx. 300,000 years old), and a modern Homo sapiens (yellow). - Image by Zachary Cofran, researcher at Vassar College in New York State.
