In a process of coevolution, flowers developed floral rewards such as nectar and longer tubes, and bees developed longer tongues to extract the nectar. Bees also developed structures known as scopal hairs and pollen baskets to collect and carry pollen.
The relationship between flowers and bees is an example of coevolution, where both species have adapted to each other's needs over time. Flowers have developed features like nectar and long tubes to attract bees, while bees have evolved longer tongues and pollen baskets to collect the rewards.