Paleoneurobiology

Paleoneurobiology is the study of brain evolution by analysis of brain endocasts to determine endocranial traits and volumes. Considered a subdivision of neuroscience, paleoneurobiology combines techniques from other fields of study including paleontology and archaeology. It reveals specific insight concerning human evolution. The cranium is unique in that it grows in response to the growth of brain tissue rather than genetic guidance, as is the case with bones that support movement. Fossil skulls and their endocasts can be compared to each other, to the skulls and fossils of recently deceased individuals, and even compared to those of other species to make inferences about functional anatomy, physiology and phylogeny. Paleoneurobiology is in large part influenced by developments in neuroscience as a whole; without substantial knowledge about current functionality, it would be impossible to make inferences about the functionality of ancient brains. Hominid paleoneurobiology refers specifically to the study of brain evolution by directly examining the fossil record of humans and their closest hominid relatives (defined as species more closely related to humans than chimpanzees). Paleoneurobiologists analyze endocasts that reproduce details of the external morphology of brains that have been imprinted on the internal surfaces of skulls. Humans have had a long interest in the brain and its functions. The first recorded study of the brain and its functions was from a papyrus text written by the ancient Egyptians during the 17th century BCE. The document details 48 medical ailments and makes references to how to deal with head wounds. Much later in the 6th century BCE the ancient Greeks began to focus on studies of the brain and the relationship between the optic nerve and the brain. Studies of brain evolution, however, did not come about until much later in human history. Comparative anatomy began its emergence in the latter part of the 19th century. Two main views of life sprung forth; rationalism and transcendentalism.