General Information	Whales are mammals, just like we are. This fact is understandably surprising and/or confusing for many people. Whales share many mammalian characteristics with their land-bound relatives, including the presence of hair (very sparse on whales) and females that have mammary glands and nurse their young. Whales are also warm-blooded, or endothermic; they maintain a body temperature around 95 degrees. The confusion stems from the fact that whales live their entire lives in saltwater and have bodies that look more like fish rather than other mammals. A whale's fish-like body is the result of millions of years of adaptation for a fully aquatic life.
Life Span	No one is really sure how long whales live in the wild. Unfortunately humans have been hunting them far longer than they have been studying them. Our best estimates at this point indicate that whales have life spans similar to humans, 60-70 years. Recently a bowhead whale died and was discovered to have a harpoon tip in its blubber layer, of a type used over 150 years ago.
Taxonomy	Every species of creature, living or extinct, is given a unique two word identification called a Latin name. Each of these species is then placed into a larger group depending on who and what they are most closely related to. This process is called taxonomy, the classification of organisms. Latin names are universal and help to overcome language barriers and local variation in terminology for animal names. For example, a mountain lion's scientific name is Felis concolor, but is called a puma, cougar, catamount, and mountain lion. That can be very confusing! However, no matter what it is used as its common name, its latin name is still Felis concolor. All whales, dolphins and porpoises are members of the Latin order Cetacea and are called Cetaceans. Cetacea was originally derived from the Greek word ketos, meaning sea monster. It's easy to imagine what ancient sailors must have thought when seeing whales. Without modern knowledge whales were extremely mysterious dwellers of the deep.
Origins	About 50 million years ago the ancestors of whales were small to medium size animals, perhaps like a dog or bear. They lived on land but spent much of their time in the water, foraging and perhaps using the water to escape predators. Millions of years passed, and these animals gradually lost contact with land. Over time their bodies became more and more suited to life in the water. Whales lost most of their external hair and the hind limbs grew smaller, eventually disappearing altogether. The tail broadened and flattened, becoming more like the fluke of today's whale. After millions of years passed, and these animals gradually lost contact with land altogether. Whales went through many changes in size and shape, generally growing larger and increasing in species diversity.
Species Diversity	There are 76 confirmed species of whales, dolphins and porpoises. They can be divided easily into two major groups, Odontocetes or toothed whales and Mysticetes or baleen whales. Cetaceans live all over the world -- in every ocean, in most seas and even in a few rivers. They inhabit both salt and fresh water and range over tremendous areas spanning thousands of miles. It is a tribute to the vastness of the ocean that, even with modern science, there are several species of whales that have never been observed alive; they are known only from beached animals or bones. Baleen whales get their name because of a unique physical feature related to how they eat. Instead of having teeth as do most animals, they have 300-600 plates of a material called baleen in their mouth. Baleen is made of a protein called keratin, the same protein as found in human finger nails and hair. It is used to strain their food from the water, which they swallow without chewing it. These baleen plates vary in size and color between the different species, ranging from pure black to pale creamy white. There are 11 confirmed species of baleen whales. They can be further divided into three groups: the rorquals, the right whales and the gray whale. This grouping is based on their method of foraging and their preferred type of prey.