if you take a nice look at the southern hognose of the species heterodon ( simius) it looks like a hybrid of a heterodon nasicus and heterodon platyrhinos ( eastern hognose). i have no proof as of yet but if i cross a eastern hognose with a western hognose it is my theory that i will produce something very similar in apperance ( if not the exact same thing) as a southern hognose.
this of course is merely a intergrade if proven true because they both reside within the same species of snake ( heterodon).
these are the sort of experiments that are preformed with the use of hybridization. the origin of a species or subspecies can be determined or disproven this way.
once again i will not put the neccessary time it would take to quote my biology book to backup the statements made in previous posts of this thread this time around but i will when i get enough free time to do so.
chad elmore
http://www.diablosnakefarm.com