It has been suggested that we consider dogs to be separate species. I completely agree with that, but without human intervention, wouldn't breeds that can't rep

It has been suggested that we consider dogs to be separate species. I completely agree with that, but without human intervention, wouldn't breeds that can't reproduce naturally (great dane & chihuahua) most likely lead to separate species given enough time? http://www.scientificamerican.com/article/an-immodest-proposal/ http://www.scientificamerican.com/article/an-immodest-propos...