While I was an undergraduate physics major, my interests and research experiences were quite clearly of the pure physics variety: particle physics, cosmology, astrophysics. There was never any question about my scientific identity or goals — I was unambiguously a “physicist,” and with that label implicitly came values about what I was supposed to study and how.
When I began graduate school, however, I found a new interest: biophysics, an interdisciplinary science if there ever was one. While Rutgers has many physics Ph.D. students and faculty studying problems in biophysics and quantitative biology, I couldn’t help but suffer a bit of an identity crisis, albeit one more professional than adolescent in nature (not so much “Who am I?” but rather “What kind of job will I be able to get?”). This seemed exacerbated by my specific research, which focuses on evolution; while physical analogies abound within the mathematical models, the phenomenon itself is plainly biological. So when describing my work to others, I had to wonder: am I still a physicist? Or am I a biologist? Am I some type of hybrid, i.e., a biophysicist, and if so, what does that really mean?
Over time, though, I’ve come to believe what defines our identities as scientists is not so much what we study but how we study it. More precisely, it is not the questions we ask but the kinds of answers we seek that are important in defining this identity. Many different types of scientists (biologists, chemists, physicists, etc.) in a field like biophysics are basically studying the same problems — gene regulation, biochemical kinetics, protein folding, etc. — but their actual work may look completely different from each other’s on paper. A good example is given by protein folding, the famous problem of understanding how a chain of amino acid molecules making up a protein folds relatively quickly into a unique 3D conformation (Ref. 1). To a structural biologist or a bioinformatician, so-called homology-based methods provide an adequate solution. These methods predict unknown structures of proteins using large databases of known structures and statistical algorithms. To a physicist, however, this is not really a solution at all — it is a practical tool to make predictions, but it offers no insight into the fundamental physical principles underlying how the folding process occurs.
This issue has real consequences for a discipline, beyond just a little angst for students. Despite all the good intentions of funding agencies, journals, and institutions toward cultivating interdisciplinary research, they run into problems when geneticists are evaluating physicists’ proposals by genetics standards or when mathematicians are evaluating biologists by mathematics standards. As demonstrated by the example of protein folding, scientists can have genuine disagreements about whether a problem is even solved. An interdisciplinary field must be aware of these different values and should openly discuss how to make different scientists’ goals and styles complementary for the sake of scientific progress. Indeed, interdisciplinary research has tremendous power to meet the daunting challenges of the 21st century, but only when effective communication and collaboration exist to take advantage of it.
 Dill KA, et al. (2007) “The protein folding problem: when will it be solved?” Curr. Opin. Struct. Biol. 17:342-346.