Thanks for clarification but I'm still confused. The point I was trying to make was that blue gills in different lakes in Wisconsin [or even Minnesota where I live] are still in the same kingdom phylum, genus, class, order, genus, species are they not? Where did I go wrong? Okay, okay, I'll go back and read the full article.
I understand some have defined speciation as members of the same classification that cannot interbreed, such as a chihuahua and a great dane. Is this your definition as well?
Yes, ability to interbreed is my, and the, definition.