Homologous Structures vs. Analogous Structures

Homologous Structures Homologous structures have similar anatomy but not necessarily the same function. Example: upper limbs of humans, bats, whales and cats They are a result of similar origins.

Homologous structures

Analogous Structures Analogous structures appear similar and have similar functions. Example: birds wings and insects wings. They are a result of different ancestral origins.

Analogous structures The birds wing and the insect wing have similar functions and shapes but different origins.

Convergent Evolution (the cause of analogous structures) The independent evolution of species with similar traits (analogous structures) that do not have recent common ancestors. They appear similar, but are from different branches of the evolutionary tree. They have evolved geographically isolated from each other, but because their environments are similar they have functional and structural similarities.

These two animals are not closely related although they look a lot alike.

Thylacine A recently extinct animal from Australia, Tasmania, and New Guinea. It received the common names of Tasmanian Tiger or Tasmanian Wolf because it looked like a wolf or a tiger. The Thylacine was a marsupial, and not closely related to tigers or wolves. It did not share a recent ancestor with the wolves and tigers for which it was named, but in the process of becoming the top predator down under it evolved into a similar looking animal.

Thylacine Commonly known as either the Tasmanian Tiger or the Tasmanian Wolf