You’ll find one professional’s answer below the fold. What’s missing is a discussion of genes as replicators.
from the SEP – Molecular genetics:
In official and public contexts, scientists appeal to the fundamental theory associated with molecular genetics to justify centering research on genes and DNA (e.g., see the websites of funding agencies such as National Center for Biotechnology Information). Genes are typically referred to as â€œthe fundamental unitsâ€ that are responsible for guiding all basic life processes. Usually a combination of causal and information metaphors are invoked to explain the role of genes. Genes are said to produce RNA and polypeptides, to provide instructions, or direct processes. But philosophical investigation has shown that these kind of sweeping claims cannot withstand careful scrutiny. Why, then, is so much research centered on genes and DNA? One answer to this question is that biologists are blinded by an ideology of genetic determinism. But Wagner’s defense of gene centrism suggests another answer, an answer that resonates with Keller’s explanation (2000) of why gene talk is useful.
It has been proposed that the real reason biologists center attention on genes and DNA is that genes are difference makers that can be used to trace and manipulate a broad range of biological processes (Waters 2004a and 2006). This scientific practice makes sense independently of any fundamental theory associated with molecular genetics. In the case of molecular genetics, it is investigative pragmatics, not fundamental theorizing, that drives scientific research. The basic theory suffices to explain the investigative utility and results of gene-centered approaches. The fundamental theory is, in an important sense, epiphenomenal with respect to the design and implementation of gene-centered research. On this view, the role of the fundamental theory should be understood in Latourian terms (1987, 1988), as a platform for rallying the troops and bringing resources to research endeavors. The design of the laboratory experiments and the reason why the experiments work, can be explained in terms of broad investigative strategies, the basic causal theory of molecular genetics, and the details of the experimental contexts.