available on the exhibit’s website anthropologists say Smithsonian anthropologists say anthropologists say much bigger brains http://humanorigins.si.edu/human-characteristics/brains rapidly tripled its original size anthropologists say much bigger brains anthropologists say anthropologists say 2.98 pounds http://humanorigins.si.edu/human-characteristics/brains much bigger brains anthropologists say 2 percent http://humanorigins.si.edu/human-characteristics/brains 2.98 pounds rapidly tripled its original size rapidly tripled its original size available on the exhibit’s website http://humanorigins.si.edu/human-characteristics/brains Smithsonian anthropologists say anthropologists say anthropologists say anthropologists say