"Coyne pointed out that the idea that the "'regulatory gene' is the locus of evolution" dates back to Roy Britten and colleagues around 1970, but was still weakly supported by observation or experiment.He granted that chimps and humans are almost 99% identical at DNA level, but points out that "humans and chimps have different amino-acid sequences in at least 55% of their proteins, a figure that rises to 95% for humans and mice.