Lynn Margulis is a brilliant evolutionary biologist who introduced one of the most radical theories since Fisher’s modern synthesis, endosymbiotic theory (that eukaryotes evolved by cooperation between individual organisms) but suffers from a combination of unabashed arrogance and a habit of presenting her scientific hypotheses in a larger framework that encompasses political and social theory without fundamental basis. (Dawkins hardly gets a pass on this–his vengeful, thrashing attacks on theism of any sort go beyond merely debasing rationalizations for any factual basis for religious faith and enter into an arena that a pit bull would fear to enter–but he has the good sense to largely separate his technical work from his personal hobby horse.) Margulis literally challenged the central dogma of molecular biology, albeit from an abstruse angle, and has succeeded in establishing that eukaryotes–which rely on mitochondria or chloroplasts with their own unique genome to provide energy conversion and regulation–are the result of radical symbiosis, a theory that has been almost universally accepted in evolutionary biology.
Margulis’ expansion of The Gaia hypothesis as originally crafted merely stated (that organisms do not merely evolve into or in compliance with an environment, but actually modify the environment to make it more suited to their needs) is the essential source of controversy. No “neo-Darwinist” would deny the essential necessity of co-evolution, least of all Richard Dawkins whose essential technical work in the field was focused on the fig wasps (of family Agaonidae), each species of which has definitively co-evolved with a particular varietal of fig tree. In fact, Dawkins own hypothesis of the extended phenotype–that the influence of and upon genes extends far beyond the organism and into the environment that the gene carrier interacts with–is a complementary theory to endosymbiotic theory. In essence, the utility of phenotypes of a unitary gene carrier–the expressions of its genetic code–are more than just the sum of its own individual features, but the environment and other organisms with which it interacts, are core to neo-Darwinist theory, and the roots of this can be found in Darwin’s own writings, in which he recognized that organisms influence their environment as much as the environment influences them.
Taken to the logical extension, the sum total of organic activity on the surface of the planet–the biosphere as a gestalt–evolves in a way that stabilizes conditions for life. In other words, any organism or species that is “too successful” in a destructively competitive fashion ends up weeding itself out of the gene pool, whereas a species that is competitive but also provides benefit (in evolutionary terms) to the species it relies upon ends up being ultimately more successful, just as a businessman who forms alliances with competitors to ward off short-sale operators is ultimately better regarded and more successful than “Chainsaw Al”.
Where Margulis diverges from a purely scientific approach is in her assertions that there is some fundamental principle above and beyond reproductive success that drive cooperation. The notion that the biosphere is one large cooperative organism is not supported by any conventional or accepted hypothesis of evolutionary development, and while the Earth’s biosphere may ultimately venture toward a Nash-type equilibrium as the optimum state in regard to energy regulation (i.e. that radical changes in vegetative and atmospheric albedo are regulated by the presence of biomass) this is not the result of some kind of teleological principle but merely the tendency for evolved systems to self-regulate to an equilibrium state, which occurs regardless of whether the media is organic or otherwise. In other words, once a system tends toward an equilibrium, in absence of radical changes it tends to maintain that equilibrium.
Natural selection–sometimes misleadingly referred to as “survival of the fittest” (not Darwin’s words)–is but a single, albeit significant mechanism in the overall theory of evolutionary development of life. While competitive selective pressures are one substantial mechanism that drives evolutionary change, it is not the exclusive input. Mutation, gene exchange (performed by viruses and perhaps by other mechanisms), radical change in environmental equilibria, hybridization, and other potential influences on ostensible species can all contribute to novel evolutionary development and ultimate speciation.