Niche construction, genetic evolution and cultural change

In evolution, adaptation is traditionally viewed as a process by which natural selection moulds organisms to fit pre-established environmental templates. The changes organisms cause in environments are seldom thought evolutionarily significant. However, organisms partly create their own environments by 'niche construction'. A formal model of niche construction is discussed. It focusses on two genetic loci, E and A. It assumes: (i) a population's capacity for niche construction is influenced by genes at the E locus; (ii) the amount of an environmental resource, R, depends on niche construction; (iii) changes in R affect selection at the A locus. This model produces some surprising results. For example, timelags occur between the spread of niche construction and the response to the selection it generates. Niche construction also enhances the role of phenotypes in evolution. Organisms not only carry and propagate genes, but they also modify the selection pressures that select those genes. This dual role changes the relationship between genetic evolution; individual development; learning; and cultural processes in human beings.