Quote Originally Posted by Freakie_frog View Post
Let me just throw this out there. slugs were never at any point fertile. Fertilization happens when the snake ovulates or shortly after. So slug never saw genetic material from either parent. The more likely idea is that infertile eggs were "Super spiders" didn't make it past the first cellular division. However because we don't truly understand reptile DNA and the associated mutations of it we wont be able to say for sure that the morphs are determined at the time of the first division or even later on. it's more likely that the mutation kicks in later in the embryo's development since its things like pigment and what not that are effected. With all of that said I've long said that it's naive to think that the only thing these mutations effect physiologically is skin pigment, We see kinking, cleft jaws, small eye's wobble's, duck bills ect ect. All of those this are changes to the anatomy of the animal.

Still so much to learn and discover
I'm going to try to phrase my response carefully, because I don't want to come across as combative when I really just want to understand what you're saying. I'm sure a lot has changed since my last genetics course, and a lot of what I learned is probably outdated, but I'd appreciate some clarification on some of your points.

Where does your info for slugs having never been fertile come from?

Surely if they are in fact "super spiders" that didn't make it past cellular division (or possibly not very far into it), they have received genetic material from both parents?

Although things like skin pigment are not visible in the early stages of development, the genes for it are there. The genetic material that determines the morph is there from the point of meiosis. However I believe you are correct in stating that the mutation (assuming that in your statement mutation is synonymous with morph and any associated defects) can cause problems later in development as those genes are activated during the embryos development.