Speaker
Description
Human evolution depends crucially on the co-evolution between genetically determined behaviours and socially transmitted cultural information. Although vertical transmission of cultural information from parent to offspring is extremely common in hominins, its effects on cultural evolution are not well understood. We therefore investigated gene-culture co-evolution in a family-structured population of diploids. Specifically, we derived the invasion fitness of a mutant allele that influences a cultural variable (e.g., amount of knowledge or skill) to which carriers of the mutant are preferentially exposed in subsequent generations due to vertical transmission of culture. This allows for associations between genes and culture to last over multiple generations and thus sets the stage for cultural niche construction. We applied our invasion fitness to study how genetically determined phenotypes of individual and social learning co-evolve with the level of cultural adaptive information they generate. We find that due to kin selection effects, vertical transmission of information increases the level of adaptive information in the population. We also show that vertical transmission prevents evolutionary branching and the co-existence of highly-differentiated cultural morphs. Vertical transmission may therefore play an important qualitative role in gene–culture co-evolutionary dynamics. Importantly, our analysis of selection suggests that vertical transmission of culture can significantly increase levels of adaptive cultural information under the biologically plausible condition that information transmission between relatives is more efficient than between unrelated individuals.
