Brain is thought as what makes human unique. There are substantial differences in the developmental pattern and the consequences in cognitive abilities even between humans and our closest living relatives, chimpanzees. Although we know that there are differences, when or how these changes are started to acquired is still an open research question.
A group of researchers from Switzerland, has published a paper comparing the endocranial shape of human and neanderthal brains. Studying the differences between neanderthals and humans can also provide an insight into the features thought as human specific.
Although the sizes are not so different, early studies claimed that endocranial shapes of neanderthal and human brains suggest morphological differences. Moreover, there were studies suggesting neanderthal brain development is more similar to the chimpanzees’. In order to further test this, in this paper, they used 15 neanderthal and 79 human brains and showed:
– Brains of neanderthals and humans already have some differences at birth. However, the postnatal changes follow parallel trajectories.
– Early and late differences within species show differences but are parallel between species.
– Early changes include changes in bone structure which is suggested to be related with enlargement in cerebellum, and temporal and frontal cortical poles. However, the late changes include decrease in endocranial sphericity, which is suggested to be related to continuing cranial base growth whereas there is a decrease in the brain growth.
The article is interesting especially considering the unknowns of human brain development. It suggest that brain is ontogenically similar in these species. An important question that still needs to be answered though -as also stated in the paper-: Given the developmental changes are similar, are they ancestral or evolved in parallel?
Ponce de León, M. S., Bienvenu, T., Akazawa, T., & Zollikofer, C. P. E. (2016). Brain development is similar in Neanderthals and modern humans. Current Biology, 26(14), R665–R666. http://doi.org/10.1016/j.cub.2016.06.022