A publication of the Archaeological Institute of America
Entering the David H. Koch Hall of Human Origins at the Smithsonian National Museum of Natural History brought me face-to-face with a fuzzy replica of one of our earliest ancestors, Lucy, a member of the species Australopithecus afarensis who lived 3.3 million years ago. With her hooded eyes and inset nostrils she looks so much like an ape, it's hard to believe she's one of us. Our humanity, however, has less to do with our faces than it does with our feet. That's at least the beginning of an answer to the question posed by the $20.7 million permanent exhibition: "What does it mean to be human?"
A bronze sculpture of Homo heidelbergensis is one of the highlights of the Smithsonian's Hall of Human Origins. (Brett Eloff courtesy of Lee Berger and the University of Witwatersrand)
Six million years ago, we began evolving longer feet and shorter toes, allowing the earliest humans to travel long distances more efficiently than apes. But evolution does not bestow advantages, as much as trade-offs, shown by the bones, models and videos in the section of the exhibit called "Evolutionary Milestones." Those same changes made us vulnerable to new predators. In one display, proof lies in puncture marks that a crocodile bite left in the ankle of a Homo habilis.
Much of the exhibit reflects curator Rick Potts's idea that humans did not evolve to exploit a single environment like a forest or a savannah. Instead, our ancestors adapted to survive rapid fluctuations in climate. The exhibit shows our large brains evolving during a period of variable climate that began around 800,000 years ago. The museum's side-by-side casts of the insides of ancient skulls show that the human brain tripled in size, allowing us to become the complex, social creatures we are. Here's where the exhibit's focus on the link between climate and evolution has its impact. Regions that were forests for millennia suddenly became savannahs; savannahs became deserts; ice ages came and went. And early humans specialized for narrow habitats faded. But later humans, like large-brained, Homo erectus, survived 1.6 million years to reach across Africa and Asia.
One of the exhibit's strengths lies in its focus. Other exhibits such as the Hall of Human Origins at the American Museum of Natural History in New York squeeze in a textbook's worth of information, but the narrative thread gets lost in lessons on everything from DNA to art-making robots.
In sections called "Snapshots of Survival" the exhibit manages to intertwine a compelling narrative of evolution and climate while simultaneously unraveling the prehistoric dramas told by individual bones. It's an impressive juggling act. And despite the terrible things we've done to ourselves, other species, and our environment, I exited the exhibit feeling proud to be human.