Extended phenotypes and niche construction theory

Following yesterday's class on human niche construction and on the interactions between foragers and their environment, here's a link to a report (slightly over a month old) about a conference on the notion of the extended phenotype as originally proposed by the famous evolutionary biologist Richard Dawkins and the recent debates between proponents of niche construction theory.

Here's a taste:

"... there was lively debate between Dawkins and proponents of niche construction over the role of evolution within closely coupled ecosystems. Niche construction theory goes further than EP [extended phenotype] by suggesting that organisms can alter the selective pressures acting on them by modifying their environment in many ways beyond immediate constructions such as beaver dams. In niche construction theory, the link between variations in an organism's genes and in the surrounding environment is more loosely coupled with no clear mechanism for natural selection to operate.

However according to niche construction theory, there is a feedback effect, in that the genes of organisms alter the environment indirectly, for example by improving nests, that in turn modifies the selective pressures on those genes. Dawkins argued that niche construction is really a special case of EP, relating to genes of those organisms that participate in the relevant environmental construction. But he dismissed the idea that evolution can act in a broader sense across a whole ecosystem, extending to organisms not directly involved in the niche construction. He reiterated the point running through all his books, that selection can only operate against variation of replicators, which are almost always alleles (variants) of genes. The variation in genes caused by mutation generates the different phenotypes, characteristics such as animal behaviour, that allow natural selection to work."

You can read the whole story here.