Duplication and divergence in humans and chimpanzees

It has become a truism that we humans are genetically about 99% identical to chimpanzees. The origins of this assertion are clear: among early studies of DNA sequences, nucleotide identity between humans and chimpanzees was found to average around 98.9%. However, this figure is correct only with respect to regions of the genome that are shared between humans and chimpanzees. Often ignored are the many parts of their genomes that are not shared. Genomic rearrangements, including insertions, deletions, translocations and duplications, have long been recognized as potentially important sources of novel genomic material and are known to account for major genomic differences between humans and chimpanzees. Further, such changes have been implicated in a number of genetic disorders, such as DiGeorge, Angelman/Prader-Willi and Charcot-Marie-Tooth syndromes.