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Published on: January 16, 2026
Evolution of the human brain: changing brain size and the fossil record
Min S Park1, Andrew D Nguyen, Henry E Aryan
1Division of Neurological Surgery, University of California, San Diego Medical Center, San Diego, California, USA.
Abstract:
Although the study of the human brain is a rapidly developing and expanding science, we must take pause to examine the historical and evolutionary events that helped shape the brain of Homo sapiens. From an examination of the human lineage to a discussion of evolutionary principles, we describe the basic principles and theories behind the evolution of the human brain. Specifically, we examine several theories concerning changes in overall brain size during hominid evolution and relate them to the fossil record. This overview is intended to provide a broad understanding of some of the controversial issues that are currently being debated in the multidisciplinary field of brain evolution research.
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