Our Babies, Ourselves (eBook)

I walked up the main steps of the museum, passed under the banner announcing the exhibit, and entered. It was dark, and quiet, with only a few people milling about. The ambiance suited me--it echoed my own sense of anticipated reverence. Before me, the first exhibit was a tall glass case lit from above. Inside was a child's face, set high at adult eye level so that our gazes met. There was no flesh on this skull, no eyes, no mouth, just the empty face of a child with a set of battered teeth. I froze, sucked in my breath, and stared. This was the 'Taung Baby,' a two-million-year-old Australopithecus africanus, discovered in 1925 and once thought to be the missing link between humans and apes. Long ago, when this little kid died, he or she somehow ended up in a limestone quarry where the bone tissue leaked away and was replaced by stone. Two million years later, quarry workers chucked this hunk of rock into a box of possible fossils that they routinely passed on to Raymond Dart, a British anatomist working at a South African university. Dart used his wife's knitting needles to pick away at the stone until the small face appeared. Dart was used to finding baboon fossils in his shipment, but this was no monkey, the brain was too big and the face was too flat. It was, Dart was convinced, the first evidence of the ape-human split. We know now that Taung and its relatives were a kind of human that walked upright but still had small brains, and that they were possible ancestors of our species, Homo sapiens. A child, then, led the way to understanding our past. And here was that same face that Raymond Dart had looked at sixty years before.The face is gray stone, dished in from forehead to mouth, but with a flat nose. The eyes, were they in their sockets, would stare straight ahead. The right side of the inner skull is filled with a geode, sparkling crystals that give Taung a jewel-like glow. And that is appropriate. This skull, and the stone impression of this child's brain that Dart also found, are as precious as diamonds to those who are trying to figure out the human path of evolution. Staring at that skull, I was struck by the fact that this ancient child was somebody's baby long ago. Perhaps she was sick, or maybe he was accident-prone, or perhaps this baby was some predator's dinner. Standing there, I could picture him or her long ago, smiling, laughing, and reaching out to grab a mother's breast. It was the most beautiful thing I had ever seen. From a biological point of view, the Taung child represents a specific stage of development for Australopithecines, our ancestors that lived from four to two million years ago. Paleontologists tend to concentrate on adults of any species because adulthood is the mature end product, but fossilized babies and children also give clues to anatomy and physiology, to rates of development and growth. Children are not just miniature versions of adults. There are sound evolutionary reasons why infants and children look and behave the way they do, childhood is a specifically evolved stage in the life course. The Taung child emphasizes the fact that we are not born as adults but go through a lengthy period of growth and change. In this child, and all children, are some of the most important secrets of our anatomy and behavior. There are reasons why mice are born blind and human babies cannot hold their heads up. Natural selection has opted for fawns to stand on their own soon after birth, for human infants to smile automatically, and for baby chimpanzees to cling to their mothers' fur. And all of this makes some sort of natural biological sense. The pattern of birth, infancy, and childhood in any species...