Given the nature of the subject matter dealt with by the life sciences and the human sciences, there is unsurprisingly a long history of reciprocal influence between them. In particular, their respective objects of study demand methodological pluralism and an awareness of historical complexity. But comparative politics, in general, and democratization studies, in particular, have also been attracted by the causal precision and analytical rigor associated with the physical sciences. In addition, borrowings from biology fell out of favor because of their apparently antidemocratic ideological connotations. However, this essay recommends renewed openness to analogies derived from modern biology, as a corrective to overly mechanistic causal modeling, and as a means to refresh ossified metaphorical imagery that has accumulated from the physical sciences. It contests the view that biological analogies need contain antidemocratic hidden assumptions, but it accepts that since analogy is not homology, imagery borrowed from elsewhere should be used only as an aid to concept-formation, not as a straitjacket.