Mammals whose history has been speculated upon, with two very different stories resulting. First, the Darwinian scientific explanation tells how their ancestors originally came out of the sea when other forms of life started to inhabit the land, and then later as mammals they returned to the sea to make a living. Then there is the much older mythological pseudoscientific explanation, favored by people of the new age movement, that claims that dolphins came from a part of the planetary system of Sirius, and were sent here to help humankind to flourish and be happy.
The Darwinian evolutionary explanation understands dolphins to be small whales belonging to the same aquatic order as the great whales, Cetacea. Although living their entire life in the sea, dolphins are not fish but warm-blooded mammals who returned to the sea 65 million years ago in search of food, probably when the forests dried up during the heat and drought of the Pliocene era. During the following millions of years, as their lifestyle altered, their entire bodily structure became adapted to their new environment. Hair was lost, nostrils became blowholes, and because they had to swim in the sea and no longer walk on the land, their front limbs developed into flippers while the hind limbs fused into tail flukes. But two very important aspects of their land existence did not change: they still breathed air and they remained viviparous, capable of giving birth to, and suckling, live young.
Dolphin, a game fish that inhabits the waters of southern regions, possesses an iridescent coloration and can grow to a size of 50 to 60 pounds. Despite sharing a name with a mammal, the two animals are unrelated. Dolphin is a prized food fish with a flavor that is highly regarded, and can be cooked in a manner similar to swordfish.