Some animals are better than others for eating and spreading seeds. If a plant could choose it might prefer birds eat its fruit, especially over animals with molars that crack the seeds. Not coincidentally, the active ingredient in hot peppers, capsaicin, impacts mammals but not birds.
It might very well be coincidental, because the hot compound also has anti-fungal properties. So the primary evolutionary benefit might have been that, not selection of animals eating the seeds.
jrkatz|6 years ago
petschge|6 years ago
purple_ducks|6 years ago
It is coincidental. Evolution doesn't plan.