Homozygous Spider Morph

[OhhWatALoser]

I said it was logical and likely that spider was co-dominant, and homozygous lethal, and I believe that.

I did say it was definite that spider isn't dominant, because, by definition, there is no difference in phenotype between a heterozygous and homozygous animal, with a dominant gene. The very absence of homozygous spiders means that the homozygous animals cannot be identical to the heterozygous animals--something is different, or they would exist.

Now, this is simplistic, as there quite simply are more options than just recessive, incomplete dominant, and dominant, but without getting incredibly complicated, spider simply can't fit into the definition of a dominant gene, so it has to be something else.

Now, I'm personally unaware of any scenario that would prevent 2 copies of a gene from ever winding up in the same animal, and I'm unaware of any scenario that would enable a snake with two copies of a gene to pass on a normal gene. That doesn't mean no such scenarios exist, but do you know of any such instances? That would, logically, seem to be the only alternative to the idea that homozygous spiders die before hatching.
Obviously, either homozygous animals are created, but don't live, or they are not created. If you believe there are other options, I would be curious to hear what else you think it might be.

I do not think either of the two above scenarios could be said to be present in any normal case of dominance, though.

how bout the case where its a completely normal gene and we haven't had one prove out publicly? There has only been one public pin and only one public congo. You do realize what It takes to "prove" out a homozygous dominant animal, correct? It's not out of the realm of possibilities that there just isn't one publicly. The absence means nothing, since there could be homozygous spiders out there, just not proven publicly.

there no more proof of a lethal spider than the scenario above, you keep saying absence is proof..... it's not, i'm sorry.

know what else we haven't seen homozygous of? Avalanche, Banana, Black Belly, Black Head, Black Lace, Calico, Champagne, Coral Glow, Daddy Gene, Desert, Ember, Epic, Fader, Granite, Het Highway, Spark, Josie, Marble, Napalm, Orange Glow, Philistine, Reaper, Shatter, Spector, Sugar, Whirlwind, Whitesmoke, Woma. Are they all co-dominant also since there is an absence of homozygous forms of them, or maybe it's just not proven yet.....