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Compare the Brains

Compare the Brains

The evidence that Homo floresiensis was a reasonably intelligent early species of small-brained human is exciting but sketchy. Anthropologists have found only one near-complete skull of the species, and a debate rages over whether this individual—a roughly 30-year-old, three-foot-tall female—was typical. One thing is clear, however: her brain was closer in size to a chimpanzee's than to a modern human's. Below, examine three endocasts, or approximate models of the brain, made of each of the three species. Click and drag on the images to rotate them. (Requires QuickTime plugin)

Adult Female Chimpanzee

Length: 4.3 inches
Breadth: 3.5 inches
Height: 3.0 inches
(avg. measurements for seven individuals)

Adult Female H. floresiensis

Length: 4.7 inches
Breadth: 4.0 inches
Height: 3.2 inches
(measurement for one individual)

Modern Woman

Length: 6.6 inches
Breadth: 5.0 inches
Height: 4.8 inches
(avg. measurements for seven individuals)

Note on Endocasts
The measurements above come from a March 3, 2005 paper in Science, "The Brain of LB1, Homo floresiensis," by Dean Falk et al., 308: 242-245, table 1. Dr. Falk and her coauthors generated measurements of the Homo floresiensis brain cavity using a "virtual endocast" created with computer tomography (CT) scanning data. The Homo floresiensis endocast pictured here is a cast from those CT scan data. Experts created the other two endocasts above by pouring material into the brain cavity of both a chimp skull and a modern human skull. The chimp and modern human measurements came from other endocasts also prepared that way.