I have no idea what that even means.
I know. It's one of the unfortunate consequences of a belief in philosophical naturalism. Logical fallacies, non sequiturs, lack of critical-thinking ability and many other problems follow from it.
Basically, what you don't understand is that certain terms cannot be true outside of a certain philosophical position because they are defined by it. If you replace the word 'scientific' with 'philosphically natural' you will see that it is true by definition, also known as a tautology.
Since philosophical naturalism does not recognize the term 'kind', it is impossible to define it such that it is a philosophically natural term. It is the converse argument of claiming that 'evolution' as a term must be defined biblically in order to be valid and is a non sequitur.