The evolution of enhanced conceptual complexity and of Broca’s area

Abstract

Abstract Evolutionary change occurs most often through the modification of pre-existing structures. What were the pre-existing circuits in our primate ancestors that paved the way for human language, and how did they change in the lineages leading to our present condition? Among the neural modifications that were critical for human language, there are two of special interest: The origin and evolution of the remarkably rich conceptual world that humans share to the exclusion of other primates (which made possible increasingly sophisticated communication systems), and the origin of neural circuitry that underlies various sequential and hierarchical aspects of language, as utilized for example in syntax and word morphology. The fossil record of brain evolution and the archaeological record provide intriguing clues about these processes.