ANTHROPOLOGIST Dr. Mary D. Leakey has aroused our imaginations more than ever with the astonishing discovery in northern Tanzania of two sets of footprints 3.6 million years old. The prints are thought to be those of a man and a woman, who, as Dr. Leakey described it in the National Geographic, had "come from the south" and progressed "northward in a fairly straight line." The footprints ended abruptly at a "chaotic canyon." The man walked a little ahead of the woman. And at one point the woman turned off her course for a moment, and then continued on.

Naturally, scientists are elated by this discovery. For one thing, the footprints prove we had ancestors who walked upright. And so far bipedalism is the only sure element that distinguishes man from other primates. Once man was able to walk on two legs, his hands were freed for more inventive purposes. Then, according to Dr. Leakey, his brain expanded to meet the challenge. For that we will have to take her word.

As for what this discovery does in terms of the various theories of creation, that is hard to tell. The footprints only prove that at some point in the evolutionary process man stood and took a walk. The evolutionary process itself, of course, is not in doubt, nor has it been since Darwin and others showed the oldest fable of creation to be just that. You remember the story -- the one about the man and woman who lived blissfully together until a serpent tempted the woman and the woman tempted the man, after which -- what was it now? -- they both were made to walk from their haven toward the real world which lay before them not unlike a chaotic canyon. It may even be possible that the woman regretted her action, and paused to turn back as she was walking away.