Land Animal Swims

Humans can learn to swim amazingly well by imitating the movements of other animals who left the land and became Dolphins, porpoises and whales. Fast swimming by humans is not much more than eighty years old. Present day Butterfly stroking was initially called the 'dolphin' and even today the butterfly kick is called the dolphin kick. You might remember in the Athens Olympics a Japanese swimmer got into trouble with the judges when, in a breaststroke event he pushed off the far wall and underwater executed an illegal 'Dolphin kick' to get more propulsion before he broke the surface. Underwater cameras showed for all the world to see what he had done, probably in the excitement of the moment. In subsequent heats he didn't do that. Dolphins and porpoises swim with astonishing speed, and yet they are animals, not fish. Sharks vanish when there are much faster, more intelligent porpoises around.

Human swimmers copy the undulations of the porpoise. In the freestyle the trajectory of the hand through the water duplicates the slicing action of porpoise and dolphin fin and body movements. In physics the human hand and arm's movement in the freestyle resembles  the action of a screw, the propeller of a boat, not the pulling backwards of the awkward paddlewheel steamer.  Having had no time to evolve for swimming, the human leg is a pretty poor fin, but even there the freestle kick can have undulations which reduce drag. This can be practiced by not breaking the surface too much, and by not bending the knees too much. Some swimmers practice with rubber fins on their feet. I doubt serious competitive swimmers use fins in training. The world record for swimming with fins, very long fins underwater for 50 meters is eleven seconds. French, I think.

Humans are nudged just a little toward evolving into better swimmers by diving for pearls. Japanese women pearl divers can stay underwater without air for somewhere between five and seven minutes. But only after years of practice.  See, this is a hint at how evolution can begin: an imperative, and much painful practice.

More on swimming, and the luxurious, sensuous pleasure available in swimming faster, in another, future journal entry.

Barry