This title is not new! It is taken from an article recently published in Science written by Jon Cohen. When the Chimpanzee Genome was published in 2005, there was a media frenzy suggesting that we now had proof that Chimps and Humans share approximately 99% of the same DNA. This misunderstanding has persisted for more than 25 years and was originally based on a comparison of protein coding genes between the two species. Nevertheless, by definition, this comparison could only be based upon protein coding genes that both species possess. We now know that humans possess hundreds of genes that are absent in the chimpanzee. 

A closer examination of the published data arising from the chimpanzee genome project reveal other profound differences which make the claim of 1% difference look somewhat foolish. These include: (1) Basic chromosomal structural differences between the two species including the number of chromosomes, the position of centromeres and the number of segmental inversions and relocations; (2) Profound differences between each species in the DNA sequence within the telomeres at the ends of each chromosome; (3) Unique DNA sequences in each species involved in the intimate and complex control of similar genes; and (4) Radically different and species-specific regions (i.e. hotspots) involved in genetic recombination, an initiating process in meiosis leading to the formation of sperm and egg.

More recent work has highlighted differences between humans and chimpanzees that are much more profound than previously recognised. For example, Oldham et al. published a paper describing genetic networks in human and chimpanzee brains in the Proceedings of the National Academy of Sciences. According to these authors, 17.4% of the network connections in the brain were found in the human but not in the chimp. In addition, Matthew Hahn and co-workers have reported a 6.4% difference between human and chimpanzee gene copy number in the December 2006 issue of PLoS One.

With the continuing publication of data from the ENCODE project reported here, it will become increasingly difficult to maintain the mythology of the 1% difference between the two species. The implications for Darwinian Evolution are enormous.