The Downside Of Being Upright

Anyone who thinks that six million years of human evolution has created an optimally designed, anatomically perfect human has never looked closely at his own body. For every benefit that natural selection crafted into the new body plan, trade-offs left the new organism with anatomical or behavioral dilemmas. As the biped gained stability, it lost power. As it gained energy efficiency while striding, it lost that efficiency while climbing. For pregnant women the trade-offs were terrible. Natural...

Nest Eggs

A far safer parlor game than the guesswork about australopithe-cine social behavior is their ecology. After all, while social behavior doesn't fossilize (although male-female size differences may fuel speculations about mating systems), the animal's relationship to its physical environment may be revealed more clearly. It's hard to imagine how an early apelike hominid could have survived the African night unless it slept in trees as modern chimpanzees and bonobos do. Another pretty reasonable...

The Modern Biped Homo Sapiens

By the time of the arrival of anatomically modern people, bipedal walking had been the law of the hominid land for more than 1.5 million years. People had not only been walking the long distances required in their migrations, they also used their long legs for finding meat as efficiently as modern hunting-and-gathering people do today. The shift from pursuing to ambushing prey happened long after modern people had become fully bipedal. It may have occurred when modern people began to occupy the...

Take A Deep Breath

Natural selection has turned some of the lemons of becoming bipedal into evolutionary lemonade. Some traits may have paved the way for revolutionary changes that were only nascent when we stood up and walked. A human diaphragm is a membranous web attached to the rib cage and vertebral column and located on top of the body's major internal organs. It contracts to help the lungs draw air and life-giving oxygen into the body. This contraction simultaneously helps blood circulate upward toward the...

Wrist Action

You might think that walking on four legs would be a more logical precursor to walking upright than climbing vertically, but most researchers feel the opposite is the case. Being an adept climber preadapts the body for a later transition to bipedal walking. Climbing requires longer arms than legs, a torso that can assume a vertical posture, and grasping hands and feet with long curved fingers and toes. Most of all, habitual climbers must be able to move in multiple dimensions while ascending...

Bibliography And Further Reading

A new hominid from the Upper Miocene of Chad, Central Africa. Nature 418 145-51. Dart, R. 1953. The predatory transition from ape to man. International Anthropological and Linguistic Review 1 201-19. -. 1959. Adventures with the missing link. New York Harper. Darwin, C. 1871. The descent of man and selection in relation to sex. London J. Murray. Elliot-Smith, G. E. 1923. The study of man. Nature 112 440-44. Engels, F. 1896. The part played by labor in the transition...

The First Steps

There is, I believe, a far more plausible theory for the origins of bipedal walking. To understand it, we have to shake loose the notion that it had to happen for one reason or in one step. Like everything else in our anatomy, the components came together at different times and for different reasons. Rather than see the first steps as a clean break with the past entering a new habitat or beginning a new way of life it makes much more sense to view bipedalism as emerging when an ape that was...

First Step

Raymond dart, professor of anatomy at the University of the Witswatersrand in South Africa, faced a dilemma that day in 1924. Two burly men wearing the uniforms of South African Railways were coming up the driveway of his Johannesburg house. They were lugging two large wooden crates, cherished prizes that Dart had been anxiously awaiting for the past week. But the timing could not have been worse Dart was watching the delivery from the window of his bedroom, where he was struggling into an...

Everybody Loves Lucy

The annual meeting of the American Association of Physical Anthropologists convened in Denver in the spring of 1994 for a four-day succession of academic slide presentations delivered in darkened rooms by both veteran scholars and nervous students of human evolution. As always, the subplots were many academic gossiping in the corridors about the latest discoveries, tenure decisions, and hirings. Like many others, I remember only one paper from that meeting a report of the discovery of new...

Humanity Writ Large The Neandertals

The label Neandertal took on a pejorative connotation decades ago it implied boorishness at best and stupidity at worst. But the depiction of the Neandertals as brutish cavemen makes no more sense than if a future race of humanity were to depict us as such today. Discovered by miners in the Neander Valley near D sseldorf, Germany, the first specimen came to light in the 1850s. No one knew what to make of it. Most experts considered it evidence of barbarians in the ancestry of modern Europeans....

What Apes Do And

Unlike us, apes walk around all day on all fours, and their ancestors walked this way too. That walking with all four legs on the ground was an important part of the lives of ancestral apes makes much sense to anyone who has spent time following modern great apes around African forests. The African apes travel mainly on the ground, ascending into trees to search for fruit or to spend the night. Despite their long arms and curved fingers, chimpanzees and bonobos are well adapted to ground...

Be Cool

Dogs pant when they're hot, slobbering all over your carpet as they do. We sweat, sometimes profusely. A baseball pitcher can lose ten pounds of body fluid while putting in nine innings on a hot July afternoon. People who lose the ability to sweat the New York Yankee great Whitey Ford had this medical problem surface late in his career are in grave danger of lethal overheating. When early humans began to walk upright, their walking no doubt took them out of the forest and into blazing tropical...