What favors the evolution of drug-like molecules?

Placeholder - I've suggested to ASM that one session next year cover whether and how multicellular organisms exert selective pressure that favors the evolution of drug-like natural products. I plan to write more about this more, here, but for now this is what I submitted to ASM: "Small molecules (natural products) transformed the practice of medicine, but we do not understand what evolutionary pressures yielded their important biological activities. In the case of commensals and primary pathogens, the host itself likely provides selection. How do natural products alter the host to favor colonizing microbes? Understanding this dynamic will crucially advance the prediction and measurement of novel activities." I recommended these speakers: Michael Fischbach Nancy Keller Gillian Turgeon Christian Hertweck Johnathan Walton Any others you recommend for the session?