Darwinian evolution evolves foresight fix?
So contend Salverda and de Visser in Current Biology,
Given that there is genetic variation in evolvability, how can it evolve? This is not straightforward, as natural selection benefits organisms with high fitness and not those with increased evolutionary potential. In order to evolve by natural selection, variants with increased evolvability must be associated with direct or indirect fitness benefits. Direct positive effects on offspring fitness are unlikely, at least for short-term evolvability, because genotypes that produce relatively many beneficial mutations tend to be those with relatively low fitness [7]. Variants with increased evolvability thus rely on longer-term benefits arising from the association with rare beneficial mutations, which they produce at an increased rate. Such second-order selection due to hitchhiking with beneficial mutations (Figure 1) is also the mechanism by which mutators, i.e. mutants with an increased mutation rate, reach high frequency in microbial populations [8].In the new study, Woods et al.[2] report a detailed demonstration of second-order selection of evolvability in a large population of the bacterium Escherichia coli. Read More ›