"You need to read the definition again and pay attention to the bold print:
A common definition is that of a group of organisms capable of interbreeding and producing fertile offspring of both genders, and separated from other such groups with which interbreeding does not (normally) happen. Other definitions may focus on similarity of DNA or morphology. Some species are further subdivided into subspecies, and here also there is no close agreement on the criteria to be used.
Because there is variation we are going with the "common" definition. In the "common" definition there are "norms" of breeding. This allows for variation from the norms within the same family. The family is divided into subspecies which show variations within the same family. One family of species does not evolve or interbreed with another family of species.
This is really elementary."
Prexactly the point that you seem to be consistently missing despite the numerous occasions it has been clearly pointed out to you.
The definition of species is arbitrary. The clue that it is is when the words 'other definitions' and 'variations' was included.
Have you addressed the complications with your 'working' and 'common' definition of species when considering the asexual reproduction stuff that virus and bacteria do?
If it were so elementary, you would have grasped it and we would not be spending so many electrons discussing it.
