What Genes Can’t Do

What Genes Can’t Do, by Lenny Moss, doesn’t quite deliver on its title’s promise of a thorough critique of genetic determinism. The book is much more limited in its scope than the title would suggest. But within its own boundaries, the book does argue cogently and make some important points. Moss is a philosopher with a background in cell biology; he’s able to go into detail on both the history of biologiy, and on current work in the field…

Moss’ basic argument is that the extravagant claims made for genes and the genome as ultimate determinants of life processes rest on a conceptual confusion. There are two ways to talk about genes: one is to trace what proteins a given gene actually “codes for” the synthesis of; the other is to refer to genes in terms of the differential effect on the phenotype of a particular presence or absence. There’s a huge gap between these two meanings. The gene whose absence often leads to cystic fibrosis codes for “a transmembrane ion-conductance regulator protein” (47). This protein has many roles in many parts of the body. But the effect of the gene’s absence (as opposed to it usual functioning) is mostly felt in the pulmonary system, where development is disrupted, leading (not invariably, but in a large percentage of cases) to cystic fibrosis.

So there are two ways to talk about what this gene ‘does.’ One way is in terms of the actual protein synthesis it provides a template for (though, of course, such synthesis is mediated by RNA and many other cellular factors, including the ones that turn the gene on and off in response to various environmental cues). The other way, an instrumentally useful one, is to correlate its absence with the statistical probability of cystic fibrosis. The point is that there is no seamless connection between these two ways of talking about the gene. We don’t understand all the things that the gene does in helping with the development of the lungs, nor do we understand the full process by which cystic fibrosis develops. To call this gene a gene (negatively) for cystic fibrosis, or (positively) for pulmonary development, is as misleading as to say that a spark plug is what causes an automobile to move (since the car won’t function correctly in the spark plug’s absence).

Moss’ point is that it is only by confusing these two meanings of the gene that we get the idea that the genome is the Book of Life, or the “text” or “information” that uniquely determines what the organism is and does. A proper understanding of the gap between the two meanings will lead us, instead, to look at the complex pathways by which the organism actually does grow, function, and reproduce. There are all sorts of steps between the mere presence of DNA and the actually-existing phenotype.

On the one hand, Moss is just emphasizing the complexity of actual biology – in ways that any scientist would endorse – in contrast to the silly generalizations that crop up in the press about the genome as the recipe for life. Even if we did recover a dinosaur’s complete DNA, we couldn’t just put it in an incubator and expect a dinosaur to emerge. We’d need a dinosaur’s eggs as well, and the environment in which those eggs are laid and protected.

But that’s not all. On the other hand, Moss actually is criticizing the dogma of the gene’s centrality in ways that cut against the mainstream of contemporary biology. He rejects both the ‘gene-centric’ view of Richard Dawkins, and the excessive cult of DNA to be found in the likes of James Watson. He insists, instead, on an “epigenetic” view: the view that the development of the organism from fertilized egg to mature individual is not just predetermined, or “coded for” by the genes, but is itself an active and contingent part of the growth process. “Information” is carried in the cytoplasm as well as in the chromosomes; the “decoding” of DNA is not something that genes can do by themselves, but rather something that presupposes the functioning of the cell as a milieu, and the larger environment within which the cell finds itself.

Thus Moss endorses some relatively non-mainstream paradigms within biology, from Freeman Dyson’s proposal that DNA and RNA themselves were not at the origins of life, but started out by being parasitic on self-organized, self-replicating protein cycles; as well as the Developmental Systems Theory of Susan Oyama and her colleagues; and the recent suggestions by Evelyn Fox Keller that the “century of the gene” is now over. On the other hand, he convincingly critiques Stuart Kaufman’s currently fashionable work as being empirically weak, as well as being less of an alternative to mainstream genetic determinism than it seems.

Moss knows his science intimately, as well as the history of science, and he is at his best in giving detailed accounts of research programs and developments in the life sciences. His critique of mainstream biology is empirically rooted, and from within the field, rather than the sort of extrinsic criticism that I would write (or that a number of my friends actually do write). Such an empirical problematization is sorely needed.

By the same token, however, Moss doesn’t really address the larger philosophical issues that are raised by the way he sees biology. These would involve a rejection of the notion that everything (or everything that matters) is “information,” and a rethinking of how complex processes work (something that “complexity theory” has been emphasizing for some time, but hasn’t made much progress in getting to the roots of). Such considerations might lead as well to a broader reconsideration of alternatives to the current triumphalist paradigm of the positivistic, mathematicized life sciences, but along more solid grounds than the cultural critique of “science studies” has been able to offer.

What I’d like to see is a way that these considerations might hook up with the thinking of process and becoming that one finds in Bergson, Whitehead, and Deleuze; in opposition both to scientific reductionism and New Age holism. But of course I have little idea of whether such a thing is actually possible.