A team of international researchers from Germany, the Netherlands and San Diego may have shed light on why chimps and humans are so genetically similar (nearly 99 percent of shared DNA sequences), and yet so mentally different. In a study published in the April 12, 2002 issue of the journal Science, the scientists noted that the striking difference between these primate cousins is most evident in their brains. The disparity appears to be the result of evolutionary differences in gene and protein expression, the manner in which coded information in genes is activated in the brain, then converted into proteins...