Philosopher and cognitive scientist, Jerry Fodor has co-written an article with Massimo Piattelli-Palmarini in New Scientist this week, which argues that natural selection "overestimates the contribution the environment makes in shaping the phenotype of a species and correspondingly underestimates the effects of endogenous variables."
Fodor and Piattelli-Palmarini claim that more attention should be devoted to "non-environmental constraints on trait transmission. [These] include constraints imposed 'from below' by physics and chemistry, that is, from molecular interactions upwards, through genes, chromosomes, cells, tissues and organisms. And constraints imposed 'from above' by universal principles of phenotypic form and self-organisation - that is, through the minimum energy expenditure, shortest paths, optimal packing and so on, down to the morphology and structure of organisms."
Unfortunately, Fodor and Piattelli-Palmarini make two crucial conceptual errors:
(i) They conflate natural selection with adaptation to an environment.
(ii) They conflate evolutionary fitness with adaptivity to an environment.
In fact, natural selection and evolutionary fitness can be defined in abstraction from adaptation to an environment. As John Barrow puts it, natural selection "has just three requirements:
(1) The existence of variations among the members of a population. These can be in structure, in function, or in behaviour.
(2) The likelihood of survival, or of reproduction, depends upon those variations.
(3) A means of inheriting characteristics must exist, so that there is some correlation between the nature of parents and their offspring. Those variations that contribute to the likelihood of the parents' survival will thus most probably be inherited.
It should be stressed that under these conditions evolution is not an option. If any population has these properties then it must evolve," (The Artful Universe, p21).
There is no need to refer to the existence of an environment, or adaptation to an environment, in the definition of natural selection. As Lee Smolin points out, "at this formal level, concepts like 'survival of the fittest' or 'competition for resources' play no role...What is responsible for that variation, and what goes into the differential survival rates, is not relevant for how the basic mechanisms of natural selection work," (The Life of the Cosmos, p104).
As a demonstration of this, Smolin's theory of cosmological natural selection requires no environment for the evolution of its hypothetical population of universes.
In fact, the conceptual errors made by Fodor and Piattelli-Palmarini are probably shared by many evolutionary biologists, who probably do conflate natural selection with adaptation to an environment. The endogeneous constraints which Fodor and Piattelli-Palmarini refer to may well play an important role in biological evolution, and they might well demonstrate that biological evolution involves far more than adaptation to an environment. Nevertheless, such endogeneous constraints are consistent with evolution by natural selection.
Equally, this doesn't entail that natural selection is the only process operating within biological evolution. Far from it, it seems that horizontal gene transfer plays a huge role in microbial evolution, and processes such as genetic drift also play a role under specific circumstances. The fact remains, however, that the concept of natural selection is neutral with respect to the importance of the environment.