Conventional thought says that the fruit of a plant is tasty so that animals will eat and disperse the seeds. Chili peppers are sort of an exception to this rule. The current theory, which is based upon research on wild chili plants in Bolivia, indicates that the capsaicin in a chili evolved to protect the seeds from Fusarium infections. Fusarium, a fungus that invades fruits through wounds, is a leading cause of seed mortality.
At higher elevations, where moisture is high and Fusarium fungus is rampant, the scientists found that 100 percent of the plants produced hot chilies. In the drier lowlands, where fungus is less of a problem, only 40 percent of the plants produced fiery fruits. The remainder spent more resources developing thick seed coats, which protect against the devastating ant populations common to lower areas.
Capsaicin in chilies, one of the first plants domesticated in the New World, may have been used to protect human food from microbial attack long before refrigeration or artificial preservatives were available. So habanero peppers must be nature's super preservative.