“Coevolution
What evolutionary characteristics are typical of coevolving species?
Sometimes the life histories of two or more species are so closely connected that they evolve together. Many flowering plants, for example, can reproduce only if their flowers attract a specific pollinator species. Pollinators, in turn, may depend on the flowers of certain plants for food in the form of pollen or nectar. The process by which two species evolve in response to changes in each other over time is called coevolution. The relationship between two coevolving organisms often becomes so specific that neither organism can survive without the other. Thus, an evolutionary change in one organism is usually followed by a change in the other organism. Flowers and Pollinators Coevolution of flowers and pollinators is common and can lead to unusual results. For example, Darwin discovered an orchid whose flowers had a long structure called a spur. Way down at the bottom of that 40-centimeter-long spur is a supply of nectar, which could serve as food for any insect able to reach it. But what insect could reach it? Darwin predicted that some pollinating insect must have some kind of feeding structure that would allow it to[…]