A new study (abstract) described in the L.A. Times suggests that "just 10 differences on one particular strand of human DNA lying near a brain-development gene could have been instrumental in the explosive growth in the human neocortex." The DNA region, containing just 1,200 base pairs, is not a gene. But it lies near one that is known to affect early development of the human neocortex, according to the study, published online Thursday in Current Biology. Researchers showed that the region, known as HARE5, acts as an enhancer of the gene FZD8. Embryos of mice altered with human HARE5 developed significantly larger brains and more neurons compared with embryos carrying the chimp version, according to the study.