Peruse the job listings at the back of bioscience journals, and you will frequently encounter a theme: "A faculty member is sought who studies embryonic development using zebrafish as a model system." Variations on the theme include "body plan using Drosophila" or "signal transduction using yeast." Many a department of biological science has been shaped by an effort to have representation of each of the model systems currently in vogue. Other departments have developed around the use of a single model system, to provide a critical mass of researchers with a common tie.

Many biological processes are common to a variety of species. We seek to understand such phenomena by fully characterizing them in one or a few species that can serve as models to explain more general principles. Therefore, it is instructive to formally recall not only the strengths but also the limitations afforded by those model systems most often studied.

Sometimes the appeal of studying a model organism can supersede the generalizable information that it provides. Hence, it is also useful to step back and ask "What is the question that I am posing; what is the biological process I seek to understand?" rather than "To what purpose can I put this model system?"

HMS Beagle now presents a discussion about selection and use of model systems in biological studies. Participants dealt not only with biological issues, but also with historical, sociological, and political aspects of the use of model systems for research. As stated by moderator Jessica Bolker, this dialogue "was noteworthy not only for its content but also for its very existence; although the vast majority of developmental biologists use model systems, discussions of the strengths and weaknesses of this approach are few and far between."