Evolution explains the differences between the human and chimpanzee genomes

If you align similar regions of the human and chimpanzee genomes they turn out to be about 98.6% identical in nucleotide sequence. The total number of differences amount to 44 million base pairs (bp). If the differences are due to mutations that have occurred since divergence from a common ancestor, then there would be 22 million mutations in each lineage.

The mutation rate is approximately 100 new mutations per generation. Most of these will be neutral mutations that have no effect on the survival of the individual and almost all of them will be lost within a few generations. A small number of these neutral mutations will become fixed in the population and it's these fixed mutations that produce most of the changes in the genome of evolving populations. According to the neutral theory of population genetics, the number of fixed neutral mutations corresponds to the mutation rate. Thus, in every evolving population there will be 100 new fixed mutations per generation.