By; Grayson Hammond, Tj Baker, Dustin Sloop
A homologous structure is an adaptation that is similar in structure and evolutionary origin but having different functions, as a human's arm and a seal's flipper. These organisms must have originated from a common ancestor and evolved to survive in their changing enviroment. These organisms could have been seperated geographically by diverging evolution. Diverging evolution is where common species are seperated and evolve independently to their surrounding environment. This could be because of catastrophism, which is seperation by a natural event such as an earthquake.
Homologous Structures: Mammal Forelimbs
Even though they have different functions, the forelimbs of all mammals are made from the same basic skeletal design: one large bone connected to two smaller bones, attached to several small bones, and connected to approximately five digits.
11.2.2 Homologous Structures