First, let me say that I don't have time right now to address the questions about Leopard Rats marrying Corns, but I can tell you from having seen rat snake hybrids for over 35 years now, there are ALWAYS throw-backs. Progeny that tattle on the minor representative pheontype from the original gene donor. I was the first to reproduce these snakes, and the first to identify the heritability. Since then, I have produced over 500 of them, and have never seen one with any resemblance to Leopard Rats (primarily, the head pattern).
Now, what I know about the origins of the Ultras:
Before it was revealed by the originator of the Ultra Mutants that a Gray Rat Snake was used to make the first ones, they were in commerce under the name of Ultra Hypo Corns (most were motleys). Simultaneously, Frosted Corns were also being advertised. The first "frosted" corns I purchased from Andy Barr were purported to be Gray Rat x Corn hybrids. After the release of Bill and Kathy Love's first book, I approached Andy, and asked why he was quoted as saying in the book that they were pure corns. That was when the Expo was in Orlando, and I recall him finally saying to me, "well some were and some were not". He said some were made from a Gray Snow (the final product of the hybrid crossing of a Snow Corn to a Gray Rat Snake) and some were from the pairing of a pure Snow Corn to one of the Ultra types. In so much as every time I bred my Frosted Corns to Amel Corns, I got 50% Ultramels and 50% Amels (the parallel results of breeding an Ultramel Corn to an Amel Corn), it was clear that the Frosted Corns possessed the same mutation as the Ultra types. Since Mike Shiver told me essentially the same story about the origin of the Ultra Hypos (that a Gray Rat was used in their creation), commonality of Frosted Corns and Ultra types was a foregone conclusion.
On one of Rich Z's popular corn snake chat forums back in the mid 1990s, it was discussed at length (surely those threads are archived) and in the final analyses, the forum participants unofficially decided that Mike Shiver had likely been upset about getting out of the corn snake business and had therefore falsely stated that a Gray Rat Snake was used in their creation. At that time, keepers and breeders of Ultra types either chose to ignore the testimonies of Mike and Andy - in favor of being able to declare that they were not hybrids - OR realized that by the time this discussion came up, many of us had bred Ultra types into hundreds of pure corns, and it was too late to rid out inventories of those mutant products. In essence, they chose to downplay the Hybrid Issue. So be it. It is difficult (if not impossible) to sway public opinion. Especially when some forum participants have the time to lobby their views on a regular and constant basis). Meantime, I was still saying they were hybrids, until one day when a customer that was interested in buying one said to me, "I wasn't aware that the SMR Ultra types were hybrids, so I'm buying mine from so-and-so who has pure Ultra types". That was when I stopped advertising that they were hybrids, but everyone who ended up ordering one from me was told by me that they were hybrids. The facts seemed to blur with time, but every time I was involved in any thread about Ultra types, I made it a point to remind that they were not pure corns. Each time I did, it seemed that a new generation of forum frequenters were present, and had little or no knowledge of their alien origins. When I rolled out my new web site, I decided to make it abundantly clear that they were not pure corns, so just as I label Creamsicles as Inter-species hybrids between Emory's Rats and Corns, Ultra types were also labeled as hybrids from a sister species.
One thread even posed the challenge that since the originator of this mutation said he used a White Oak phase of Gray Rat Snake, someone should breed a wild-caught Gray Rat with an Amel Corn to see what happens. I was always comically amused at this line of thinking, which seems to have presumed that ALL Gray Rat Snakes possess this mutation? OR all White Oak Gray Rats (which is only a phase - not locality) would carry the mutation. To me, that's like saying since the first albino corn was discovered in NC, all corns in NC are het for Amel.
Do any of us really know the origins of the mutants of any species for sure? Unless we were there to see the first pairing, how could we? Add to that the fact that so many captive corns have escaped or been intentionally released in the wild, how can we even really know the origins of corns we personally catct in the wild? Sure, it's logical to presume that a corn snake we capture far from a city (or corn snake breeder) does not possess any alien genes derived from captive-breeding, but anyone that's worked at a zoo knows of (or has seen) Natural hybrids. When I lived in California, more than one California King x Pacific Gopher were donated to the zoo, and most (if not all) were genuinely found in the wild. Geneticist will also tell you that the likelihood of mutations springing from the pairing of two different species (inter-species), is more likely than mutations derived from intra-species pairings. Mutants are mutants. In the wild or in captivity, mutants are rare. Perhaps more prevalent in captivity, since unlike their wild counterparts, captively-produced corns are not exposed to the predators that prey upon corn snakes in the wild. Surely, countless thousands of mutants have hatched in the wild over the past mellenia, but the appearance of most of them were so unsuccessful, their full genetic potential never entered the gene pools. Fortunately, most mutant heterozygotes are successful in the wild, in that their phenotypes are virtually identical to their nominate forms, and therefore, ideally suited for survival in their natural habitats. It is for this reason, some corn snake mutations are still found in the wild. Some are even more successful than their nominate form, and thrive among their wild gene pools; i.e. Anerythristic Corns. Look at Black Pine Snakes and Great Lakes Melanistic Garter Snakes? Very successful mutants, indeed.
PS, as Rich will tell you, once he was convinced that the Frosted Corns were hybrids (when he bought them, he was told they were pure corns), he sold me all of those snakes. I subsequently bred them, and except for the Amels of this line looking nothing like Amel Corns, all the non-Amels looked precisely like all the Ultramels and Ultramel Aneries in our hobby today. In typical hybrid fashion, their pheontypic diversity is VAST, but everyone would call the Frosted Ghosts I produced, ULTRAMEL ANERIES.
Don
