Watt’s up with that tackles hot peppers.
Some plants do not want to get eaten. They may grow in places difficult to approach, they may look unappetizing, or they may evolve vile smells. Some have a fuzzy, hairy or sticky surface, others evolve thorns. Animals need to eat those plants to survive and plants need not be eaten by animals to survive, so a co-evolutionary arms-race leads to ever more bizzare adaptations by plants to deter the animals and ever more ingenious adaptations by animals to get around the deterrents.One of the most efficient ways for a plant to deter a herbivore is to divert one of its existing biochemical pathways to synthetise a novel chemical – something that will give the plant bad taste, induce vomiting or even pain or may be toxic enough to kill the animal.
But there are other kinds of co-evolution between plants and herbivores. Some plants need to have a part eaten – usually the seed – so they can propagate themselves. So, they evolved fruits. The seeds are enveloped in meaty, juicy, tasty packages of pure energy. Those fruits often evolve a sweet smell that can be detected from a distance. And the fruits are often advertised with bright colors – red, orange, yellow, green or purple: “Here I am! Here I am! Please eat me!”
So, the hot peppers are a real evolutionary conundrum.