Shawn Hurst

The Evolutionary Development of the Human Brain

Abstract:

The brains of apes differ from those of humans in size and shape, but early during gestational development they are similar in both. Evolution is frequently accomplished through changes in developmental timing. Comparative studies of gestational brain growth and development in apes and humans is therefore informative of the methods by which human brain evolution was achieved as well as its timing, because these can also help us better interpret the hominin fossil endocast record. In this talk I will show how the frontal lobe and especially the inferior frontal gyrus is overdeveloped compared to apes, while the occipital lobe (but not its connecting gyri) are underdeveloped. I will further discuss the evolutionary history of these changes, which appear to have occurred prior to the rapid expansion of brain size seen in some members of the the genus Homo, and how Australopithecus africanus, Australopithecus sediba, and perhaps one member of the Dmanisi fossil endocasts shows us what intermediate stages between the last common ancestor and later Homo would have looked like.

Bio:

Shawn Hurst is a bioanthropologist at the University of Indianapolis who studies brain and behavioral evolution in humans and other primates. He specializes in the study of australopithecine and early Homo endocasts and the comparative behavior and neuroanatomy of apes and humans, and is best known for his description of the endocast of DH3, Homo naledi.