Figure 1. Schematic of cultural niche construction.

Cultural niche construction results in environmental variation, which may produce two distinct forms of feedback. Route 1: a cultural trait modifies selection pressures, which can induce further cultural change. Route 2: gene-culture coevolution, where a cultural trait changes selection pressures, causes population level genetic changes in response. Evolutionary outcomes from both route 1 and route 2 depend on the frequency of T (cultural or genetic) and N (cultural) traits in the population and the selection pressures they generate, here represented by σ_i. Modified from Odling-Smee, Laland, and Feldman (2003).