The living organisms that exist upon the earth exhibit a wide array of physical, chemical, and behavioral variation. Each feature of an organism is an adaptation acquired by that species through evolution, which uniquely suits an organism to survival within a given set of environmental conditions. List your "favorite" animal and explain the unique features (phenotypical, molecular etc.) that represent a distinct evolutionary advantage. Compare these features to those of a different animal (living in the same environment). Cite your scientific references.