Often, two species face a similar environmental condition or challenge. Evolution may then shape both of them in similar ways — resulting in convergent traits. For example, imagine two flower species that are not closely related, but both happen to be pollinated by the same species of bird. A flower that gets pollinated produces many seeds and has a big advantage over flowers that don’t get pollinated.

If the bird prefers long red flowers, the flowers’ shapes and colors may evolve in ways that make them more attractive to the bird. Two flowers might end up looking the same, even though they started out looking quite different from one another. Click the button below to see how the two flowers evolve over time.