About 2 million years ago, humans began to jog - perhaps to hunt animals or scavenge carcasses on the vast savannahs of Africa. And the ability to run long distances shaped our anatomy, allowing us to evolve from apelike ancestors and making us look the way we do today, concludes a study in this week's issue of Nature.
"We are very confident that strong selection for running - which came at the expense of the historical ability to live in trees - was instrumental in the origin of the modern human body form," says University of Utah biologist Dennis Bramble, who wrote the study with Harvard anthropologist Daniel Lieberman. "We think running is one of the most transforming events in human history."
That conclusion runs contrary to the conventional theory that running simply was a byproduct of the human ability to walk. Humans are poor sprinters compared with other running animals, which is partly why many scientists have dismissed running as a factor in human evolution. But "high speed is not always important," Dr. Bramble says. "What is important is combining reasonable speed with exceptional endurance."
Scientists have produced the first simulated earthquakes designed to test how well common building materials and critical infrastructure can withstand a temblor. Researchers at four labs hope their findings will help engineers devise stronger power lines, telecommunications cables, and fuel and water pipes.
The Cornell University lab allows scientists to use hydraulic presses to produce shearing forces. Similar demonstrations took place at the University of Illinois at Urbana-Champaign, Oregon State University, and the University of California at San Diego.