Conjuring the dead: Using ancient genomics to explore the cognitive traits underlying art-making in Homo neanderthalensis and Homo sapiens
University of Edinburgh, Duke University
Early modern humans (Homo sapiens) of the African Middle Stone Age began to increasingly engage in symbolic behavior and technological innovation after about 100 kya, and these behaviors accelerated after 50 kya, giving rise to the Later Stone Age (Africa) and Upper Paleolithic (Eurasia). Neandertals (Homo neanderthalensis) of Europe and western Asia, in contrast, engaged in either symbolic expression or technological innovation, including art-making, to a lesser extent. Some paleoanthropologists attribute the behavioral difference between these species to differences in cognitive abilities, while others point to extrinsic factors such as population density that affect the expression of these behaviors. This study explored, through the lens of genomics, the neurobiological and cognitive bases for the possible behavioral differences between Neandertals and modern humans.
A list of genetic changes occurring post-split between Neandertals and modern humans was used as a pool of candidate genes and the expression of these genes was verified in brain regions that are believed to be implicated in art-making. Two genes– KRTAP24-1, HOXD4 were filtered out because they did not show any expression in the brain regions of interest. The remaining genes showed broad expression across most brain regions, making it difficult to spot areas of specialized activity. Thus, it was impossible to eliminate any other gene from consideration and narrow down the list of candidates further from the large list of 172 genes. However, the compiled information can be used to pinpoint genes that are implicated in traits of interest. One could find out genes showing enhanced activation for brain regions underlying joint attention or imagination for instance.