Are you familiar with the fact that your DNA has to be remade every once and a while. Primarily because it's in a cell that is replicating somewhere in your body and it needs more then half of the DNA of the last cell. Durning this process an average of 3 errors are made Get that [b][u]3[/u][/b]. Sometime the cells that are doing this are egg cells or sperm cell, or thee times it might be the cells that produce them. If that happens to any of the cells mentioned (which it will) the offspring of that organism (a ape in this case) will be different from the original organism. "Oh wow a whole 3 errors!" Except there's the sperm and the egg So 6 errors Chimps have 48 chromosomes 6x48 is 228 Chimps also have somewhere around 30 trillion cells [ more accurate number needed] So 30 trillion time 48 comes too 1.44ex10^15 For those of you who don't understand that it's 1,440,000,000,000,000 errors between a chip and it's kid Luckily most of the errors don't do much by them selves it takes hundreds sometimes thousands of generations to create new genes (genes in this case referring to segments of DNA that have an effect on the development, anatomy, or function of the body part). In the mean time all this extra data is locked into the DNA and more is added by errors some errors don't add anything to the DNA some simple change the genetic marker. So over the billions of years that life has existed and inconceivable number of errors have occurred in the DNA of animals to create an incredibly complex molecule (the largest know molecule might I add) yeah it's taken billions of year but there have been quadrillions upon quadrillions of replications since then creating the complex molecules that are DNA