Aristotle was one of the first great thinkers to argue that dolphins, who sleep with their blowholes above the water, are mammals. The ancient Greek philosopher had noticed that, like humans, dolphins "copulate and are viviparous," meaning that they give birth to live young.
Many years later in 1945, an influential paleontologist by the name of George Gaylor Simpson wrote that "the cetaceans on the whole are the most peculiar and aberrant of mammals—" dolphins included. Simpson claimed that the dolphin's evolution happened as a result of their opportunism, not some fated or fixed plan.
But it wasn't until the 1960s when scientists realized that dolphins didn't just evolve to reproduce like humans; rather, these warm-blooded, opportunistic cetaceans are also equipped with similar organs and urges that drive them to have sex for pleasure.
Male Dolphins Pleasure Themselves Using Eels And Dead Fish
Male Dolphins Have Members That Can Swivel And Grasp Like A Hand
Dolphins Sometimes Try To Mate With Humans
They Occasionally Practice Inbreeding
Many Male Dolphins Are Bisexual
Male Dolphins Bite During Intercourse