The fossil record generally provides incomplete information on anatomical variation and, mostly when dealing with brain, it only deals with gross external morphology. Despite these limitations, fossils are the only direct witness of the evolutionary changes, and they can supply key features able to interpret the phylogenetic history of our genus. Brain morphology is a global result of genetic adaptations, physiological responses, and cranial constraints. So, it is mandatory to investigate these three components when evaluating hypotheses on brain evolution. A proper balance of these three components is necessary to support an efficient organization of brain anatomy and functions. Severe disturbs between intrinsic and extrinsic factors (for example between brain and braincase) can lead to major functional problems. Nonetheless, minor antagonistic effects which do not affect reproductive fitness (or that have a minor and negligible influence on reproductive success) can pass unnoticed the filter of selection, involving secondary consequences, ultimately associated with diseases and pathologies due to our large and complex cerebral system.
Emiliano Bruner is PhD in Animal Biology for the University La Sapienza, Rome (Italy). He is Research Group Leader in Hominid Paleoneurobiology at the National Research Center for Human Evolution, Burgos (Spain). He is Adjoint Professor in Paleoneurology at the Center for Cognitive Archaeology, University of Colorado, Colorado Springs (USA). He employs methods and techniques from digital anatomy and computed morphometrics in functional craniology and evolutionary neuroanatomy. His main research areas concern the evolution of the parietal lobes, craniovascular anatomy, and visuospatial integration.