Abstract
The cognitive differences and similarities between Homo neanderthalensis (Neanderthals) and Homo sapiens have long been a point of study and debate, especially in the palaeoneurological and archaeological fields. Here, I revisit the controversy with the help of genetic interpretations by assessing whether there is an overrepresentation of genes associated with cognition as well as brain morphology in Homo sapiens (us). To do this, I performed a functional enrichment analysis utilising gene and phenotype ontologies on combined data (encapsulating 6545 genes) from eleven genomic studies that either tested for the predictions of functional consequences of gene variants between Neanderthals, Denisovans, and Homo sapiens, and/or attempted to capture positive selective events that occurred in the ancestral population branch of all present-day humans. Functional enrichment analysis provides a uniform way to describe the functions of genes by computationally modelling biological reality (i.e., statistically evaluating and identifying patterns within gene groups). The gene ontology enrichment results suggest that an excess of biological processes related to cell-cycle related functions, signalling pathways, and general nervous system developmental processes were prominently modified by genetic changes in Homo sapiens. Phenotypes in brain growth trajectories and cognitive traits are likely influenced by these biological processes (among other cellular and molecular functions). Some of the medically associated phenotypes related to brain function and cognition also seem to have co-evolved with Homo sapiens material culture. Yet, the trajectory of change associated with both stone tools and genetic variation in my project suggests that our ability to think about materiality is probably what differentiates us from Neanderthals. Further experiments are required to identify and confirm genetic changes, particularly their expression, in Neanderthals.
M.A. (Anthropology)