Like many biologists, I’ve wondered at times what the relatively new discipline of systems biology is all about. A lot of things get called systems biology, from genomics to metabolism to gene regulation. I often find the systems biology approaches to these fields pretty interesting, even when it’s fairly removed from my research area. Like myself, systems biologists often have a background in physics. Sometimes systems biology even includes microbial cooperation. So what ties it all together?

Well, systems biology:

• studies dynamic, complex systems whose behavior is governed by the interactions of their component parts
• uses quantitative, data-rich measurements of dynamical behavior
• uses mathematical and computational models to predict and analyze dynamical behavior

Viewed this way, I would argue that systems biology has a lot in common with ecology and evolutionary biology. In some ways, it’s just population biology applied to molecules and cells rather than individuals and species. Asking how genetic regulatory circuits create persistent cycles of gene expression rather than coming to some stable equilibrium is not all that different than asking how predator/prey dynamics create population cycles rather than coming to some stable equilibrium. And with any luck, systems biology will help bridge the traditional divide between population biologists and their more mechanistic colleagues.