This may come off as pedantic, but "identical" is a very strong term when it comes to something like chemistry. The smallest chemical difference can manifest as

This may come off as pedantic, but "identical" is a very strong term when it comes to something like chemistry. The smallest chemical difference can manifest as a large physical difference. Consider that genetically, humans are about 60% similar to the fruit fly, yet phenotically, the similarity could be considered under 1%.