Dr. Justin Ledogar, Assistant Professor in the East Tennessee State University College of Public Health Department of Health Sciences, has co-authored an article recently published in the journal Nature Ecology & Evolution. The article, “Homo sapiens and Neanderthals share high cerebral cortex integration into adulthood,” aims to better understand the mechanisms that guided changes in brain shape during the evolution of modern humans, and in particular, whether patterns of modularity or integration between cortical areas can be identified through human brain development.
The cerebral cortex has long been thought to have evolved its different regions and their unique functional specializations independently from each other. However, recent work suggests that high integration between different cortical areas during human evolution could have facilitated the emergence of highly specialized brain functions.
The authors of the new study used three-dimensional geometric morphometrics to analyze ~400 virtual endocasts representing all major living primate groups, including modern humans and apes at different developmental stages, as well as a sample of fossil hominin species.
Investigation into the relative magnitudes of morphological covariation in the sample of endocasts revealed strong covariation between different cortical areas in modern humans and Homo neanderthalensis, suggesting that natural selection favored a greatly integrated brain in both species. Further, unlike apes, modern humans and Neanderthals retain high levels of covariation between regions of the cortex into adulthood. These findings suggest that high covariation in the brain may have played a critical role in the evolution of unique cognitive capacities and complex behaviors in both modern humans and Neanderthals.