The release code words are just that: code words. They're not meant to represent some kind of underlying biological reality. OS X 10.1 was not code-named "The b

The release code words are just that: code words. They're not meant to represent some kind of underlying biological reality. OS X 10.1 was not code-named "The biological species Puma concolor", and OS X 10.8 is not code-named "The biological species Puma concolor". The code-names "Puma" and "Mountain Lion" are distinct words, ergo they represent different releases. That in biology these words refer to the same species of cat is utterly irrelevant.