Chemical Warfare In Nature

The article on tobacco plants employing nicotine in their flowers to limit access by pollinating hummingbirds is characteristic of the wide extent of “chemical warfare” in species interactions (C&EN, Sept. 1, page 11). Not only is chemical warfare in various forms common among humans (for example via pharmaceuticals, chemotherapy, mustard gas, and psychedelic drugs), but it is also common among lesser species. Well-known examples include snake venom and mercaptans emitted by skunks.

This all leads to the basic questions: How do genes become “aware” of external (or internal) threats, often of a chemical nature, and how do they develop effective chemical countermeasures to aid in species survival? Do genes somehow have access to a metaphorical chemistry cookbook? Finally, this chemical warfare contest throughout evolutionary history bears some similarity to a long-lasting chess game. It is tempting to assign chemical functional groups to the pieces on the board. Any ideas out there?

Harvey W. Yurow
San Diego