Evolutionary psychology tends to receive harsh criticism, and often rightly so. One of the main reasons for this is the severe lack of evidence for many of it's proposals given that the paucity of fossilised brains fails to bolster many a case. And it isn't even anyone's fault. That's just the way it goes sometimes, that the brain is a jelly-like substance that is subject to decay after death, and there's no way we can objectively analyse or verify any differences in brains of long ago with brains of today.This isn't set to change anytime soon, but the remarkable discovery of a medieval child's brain was the subject of a Neuroimage paper published recently. This is extremely exciting on many counts: the brain has been so fantastically preserved that it is possible to identify the frontal, temporal and occipital lobes, and even the sulci and gyri, the grooves and furrows channeled into brains.
However it is only the left-hemisphere that survived and not the entire brain, which had also shrunk to about 80% of it's original weight due to the (natural) mummification process. Although it was first discovered in 1998 and preserved all this time in a formalin solution, it was found in the skull of a 13th Century infant that was exhumed at an archaeological dig in north-west France. The body of the 18-month-old child was wrapped in leather and kept in a wooden coffin with a pillow underneath the head.
The presence of acidic clay soil and fresh briny water around the burial site is believed to have contributed towards the excellent preservation of the brain. To a certain degree, even the innate cellular structure had been preserved, so much so that intact neurons and dendrites - branched fibres that extend from the cell body of a neuron - had survived for observation in the 21st Century. It was also possible to identify grey and white matter. Apart from the external burial conditions, the toughness of the neuronal myelin sheath and collagen fibres are said to be the reasons for why the brain tissue had been nicely preserved.
It cannot be said for sure how the infant died, but the presence of an unhealed circular head fracture may have been the likeliest cause. High levels of hemosiderin suggested that the infant had heavy bleeding for several days prior to death. Poor little mite.
--------------------------------------------------------------------------------------
Papageorgopoulou, C., Rentsch, K., Raghavan, M., Hofmann, M., Colacicco, G., Gallien, V., Bianucci, R., & Rühli, F. (2010). Preservation of cell structures in a medieval infant brain: A paleohistological, paleogenetic, radiological and physico-chemical study NeuroImage, 50 (3), 893-901 DOI: 10.1016/j.neuroimage.2010.01.029
