Analogy
analogy The similarity of structure between two species that are not closely related; usually attributed to convergent evolution. Structures that resemble each other due to a similarity in function without any simi-
| A photomicrograph of Clostridium botulinum, a strictly anaerobic bacterium, stained with Gentian violet. The bacterium C. botulinum produces a nerve toxin that causes the rare but serious paralytic illness botulism. (Courtesy of Centers for Disease Control and Prevention) |
larity in underlying structure (or origin) are called analogy analogous structures. For example, birds and bats each have their forelimbs modified as wings. They are analogous because they evolved independently after the earliest birds and bats diverged from their common ancestor, who did not have wings. However, the details of their structures are quite different.
