The earliest members of the cetacean lineage were not "born with flukes" - they walked in the shallows. But how did they evolve their locomotion from normal mammalian walking into the unique vertical undulation of modern whales? A new study of an important transitional form offers part of the answer. The four-meter Georgiacetus, which lived around 40MYA, had large hips and hind legs. It apparently wiggled its feet like paddles to swim. The pelvis was not attached to the spine, and the animal could not swim the way, say, a dog does. Instead, it moved the rear of its body by muscle power to increase the kicking effect of its large feet.
COMMENT: Natural selection works in very, very strange ways, as it can be compared to a huge lab full of scientists running tests with millions of variations, large and small. Every one in a while, one of those variations turned out to be a big step forward - no matter how strange it may have looked.