Induced gene expression in human brain after the split from chimpanzee.

Despite only approximately 1% difference in genomic DNA sequence, humans and chimpanzees differ considerably in mental and linguistic capabilities, and in susceptibility to some diseases. A recent comparison of gene expression in human and great apes cast some light on the genetic basis of these differences, but more rigorous study is required. Our statistical reanalysis of these microarray data shows that there have indeed been dramatic alterations in the expression of genes in the human brain since the split from chimpanzees, mainly caused by a set of genes with increased (rather than decreased) expression in the human brain.