The evolutionists certainly do say the above. However, there is a problem with it. When we mapped the human genome, two companies did it. Only 1/5 of the genes they identified were the same. I am not sure that the chimp genome has been studied even better than man. So first of all, I am very suspicious of that statement. Secondly, that would be an example of devolution - making a species less fit. Mutations seem to do that. Thirdly, I do not know how large that gene is, but if is like most genes 500 or some base pairs long, that one mutation made it unworkable in both man and chimp is not to be wondered at. It is a slim chance, but not an impossible coincidence. Lastly, the genes of different species are never the same even if they code for the same function. That is why the sperm of one species will not impregnate another species, why the blood of one species cannot be used on another species, why the legs of one species are not the same as those of another species, etc.
First off, there is no such thing as "devolution" (except a certain '80s pop band). Evolution simply means "change." The opposite of change is "stasis."
Secondly, neither chimps nor humans make vitamin C for the very simple reason that we both get plenty of it through natural sources. When the mutation turning off our vitamin C maker appeared, it had absolutely no effect on the survival of the original owner, so saying it made the critter less adapted to its environment is clearly mistaken.
If I understand the following reference correctly, the base pairs under discussion are in fact identical.
Secondly, that would be an example of devolution - making a species less fit. Mutations seem to do that.
True, most mutations are harmful. However, this particualr one did not decrease the fitness of the organism, as it preusmably ate fruit, like modern people and chimps do. It did decrease the fitness of 'limeys' many millenia later (that's how ascorbic acid was discovered)
one mutation made it unworkable in both man and chimp is not to be wondered at. It is a slim chance, but not an impossible coincidence.
Read the article I linked to, this isn't the only such 'coincidence'.
Lastly, the genes of different species are never the same even if they code for the same function
Not true. The genes I'm talking about are a counterexample.
Thanks for a civil reply.