ADELAIDE, AUSTRALIA—Roger Seymour of the University of Adelaide and his colleagues in Australia and South Africa calculated the rate of blood flow to the brain in 12 species of hominins who lived over a span of three million years, according to a report in Popular Science. Seymour’s team based the rate of blood flow on the size of the two holes in the base of hominid skulls that allow arteries to reach the brain. They found that while brain size increased by about 350 percent, blood flow to the brain increased 600 percent. The scientists suggest that the increase in blood flow could have provided the evolving hominid brain with increasing levels of oxygen and nutrients. To read about research into the evolution of the human face, go to "Your Face: Punching Bag or Spandrel."