Environmental adaptation and homology in the skeleton
Within the group known as mammals there exists a great diversity of methods of locomotion. Some animals are adapted to a terrestrial environment, others to an aquatic environment and still others to an aerial environment. The anterior lilmb of each species has a particular form, adapted to its environment.
The comparison of skeletal organization in the anterior limbs of four different species shows that mammals display a homology of limbs (inherited from their common tetrapod ancestor).