Will Brown bring Darwin’s Down House down? Look at the title of a paper in the Annual Review of Ecology, Evolution, and Systematics by Christopher J. Graves and Daniel M. Weinreich of Brown University: “Variability in Fitness Effects Can Preclude Selection of the Fittest.” The very title suggests that core concepts underlying neo-Darwinism (fitness and selection) are in trouble. Although the paper is behind a paywall, we get an idea of the trouble from the Abstract:
Evolutionary biologists often predict the outcome of natural selection on an allele by measuring its effects on lifetime survival and reproduction of individual carriers. However, alleles affecting traits like sex, evolvability, and cooperation can cause fitness effects that depend heavily on differences in the environmental, social, and genetic context of individuals carrying the allele. This variability makes it difficult to summarize the evolutionary fate of an allele solely on the basis of its effects on any one individual. Attempts to average over this variability can sometimes salvage the concept of fitness. In other cases, evolutionary outcomes can be predicted only by considering the entire genealogy of an allele, thus limiting the utility of individual fitness altogether.
What? Can “salvage the concept of fitness”? Sounds like that key word in Darwinian theory is in need of rescue.
CEH has often claimed that natural selection is indistinguishable from the Stuff Happens Law: i.e., it relies so heavily on chance (both mutation and selection) that it cannot make predictions, and therefore fails as a scientific explanation. More.
It’s a classic tautology. The fittest survive and how do we know? Because they survive. The great strength of a tautology is that it can’t easily be proven wrong. 😉
See also: Can sexual selection cause a decline in evolutionary fitness?
Engineering Tradeoffs and the Vacuity of “Fitness”