“Whereas Dr Wildman’s team find that chimps and humans are 99.4% similar, other researchers last year put the similarity at around 95%; the figure you get depends on precisely which genetic differences you look at.”
DNA mechanisms for reproduction are not a blueprint but a recipe. This BBC article does not mention that the 95% figure for chimp vs. human comparison takes into account how the recipe is followed and therefore may make more sense. i.e. it does not merely look at the ingredients of the recipe, the DNA sequences, which have usually indicated more than 98% concordance.
BBC NEWS | Science/Nature | Chimps genetically close to humans via Kottke