Organism Physiology

Organism Physiology Paper
June 10, 2012
Shawn Flanagan

Organism Physiology
Dolphins are one of the most popular mammals in the ocean, and are not considered fish.   Because of some of the physiological structures dolphins have, scientists believe that these mammals could have evolved from a terrestrial ancestor (Dolphin Research Center, 2007).   Throughout this paper, it will discuss how dolphins have adapted to its environment, how its evolved to survive in that environment, and it will show a diagram of the different structures that make it possible for them to adapt.
In the Beginning

The dolphin is said to of come from animals called cetaceans, on theory says that these cetaceans are from an animal called a Mesonychid that lived 55 million years ago and ranged from the size of a dog to the size of a bear.   Throughout the millions of years, these mammals changed and evolved to better fit its environment.   When these animals found an unoccupied area, they would evolve to that specific area.   This evolution played a significant role in making what individuals have become to know today as dolphins (Dolphin Research Center, 2007).
Evolution and Adaptation

In the external diagram above, the pectoral fin, also known as the flipper, has a skeletal structure like that of a humans arm and hand.   Inside this pectoral fin, is a radius and an ulna, with five phalanges just like that of a human hand.   Dolphins also have a humerus that has a ball and socket like that of a humans arm (Dolphin Research Center, 2007).
In the internal diagram above, it shows the layer of skin, or blubber that a dolphin possess.   This blubber is essential to the dolphin so that in the colder waters they can adapt to be able to survive.   The top layer of skin comes off every two to four hours so that the dolphin can glide better in the water and so that other organisms cannot attach to them (Dolphin Research Center, 2007).
All mammals are warm blooded and can...