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 catsThey 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 structuresThe 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.

ThylacineA 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