The elusive homozygous spider...?

isnt normal a dominent morph? wouldnt the same apply as breeding two normals?

"normal" isn't a morph.

When we reference "morphs" for BPs, we are talking about genetic mutations which visible physical changes. These changes are the cause of single mutated genes.

A "normal" ball python has none of these genes, there is no single gene that causes the look of a normal ball python. Therefore it is not a morph, and cannot be considered dominant or recessive or anything, since those terms only apply to how genes interact.

Is it just me, or have they been around long enough that the probability is that there isn't an homozygous spider?

Brandonsballs

If spider was Dominant then when bred with a female all offspring would have to be "spider" in appearance, assuming that spider being dominant that it is also homozygous in that sense.

But if a spider is paired with a normal and normals are hatched from the clutch then one would assume that by these results that the spider is in fact co-dominant and merely heterozygous.

I need a spider so I can breed with a normal and see results. This sounds very intriguing. Good luck on your pairings. :gj:

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Originally Posted by Turbo Serpent

If spider was Dominant then when bred with a female all offspring would have to be "spider" in appearance, assuming that spider being dominant that it is also homozygous in that sense.

But if a spider is paired with a normal and normals are hatched from the clutch then one would assume that by these results that the spider is in fact co-dominant and merely heterozygous.

I need a spider so I can breed with a normal and see results. This sounds very intriguing. Good luck on your pairings. :gj:

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Actually no this is not the case....

A Dominant mutation still can only pass on one copy of the gene to the offspring.

Dominant mutations are visually identical wether they are heterozygous or homozygous carriers of the gene

If the parent is a Heterozygous Dominant gene carrier bred to normal Statistically 50% of the offspring will be Heterozygous carriers (Visual) and 50% will not be carriers (completely normal)

If the parent is a Homozygous Dominant gene carrier bred to normal
All offspring will be Heterozygous cariers of the gene. Thus they will look identical to the Parent Homozygous carrier but only be heterozygous carriers themselves (1 copy of the gene)

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Originally Posted by BrandonsBalls

Is it just me, or have they been around long enough that the probability is that there isn't an homozygous spider?

Brandonsballs

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Actually, the fact that they have been around for a while makes the probability that there IS quite a few homozygous spiders out there, unless it is homozygous lethal, but since I have seen nothing other than speculation on that point, I'm inclined to believe it is not lethal.

I think what you meant is that the homozygous form is probably not visually different from the heterozygous form, and yes, no one is expecting a visually different homo form to turn up. If it had one, it would have been seen by now.

Don't mean to give you a hard time, but: isn't it just as much speculation that there might be a homozygous spider as that spider might be homozygous lethal? No one seems to have any good proof of either so why would one opinion be more likely than the other.

Also, if homozygous spider is possible then the difference between seeing the first one and proving it through breeding should be a limited number of years. What I'm getting at is why should everyone have given up on ever seeing a visually different homozygous spider years and years ago yet still hold out so much hope for proving a non-visually different homozygous spider through breeding? I realize every spider doesn't get bred at two years, especially the females but when was spider declared dominant anyway?

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Originally Posted by RandyRemington

Don't mean to give you a hard time, but: isn't it just as much speculation that there might be a homozygous spider as that spider might be homozygous lethal? No one seems to have any good proof of either so why would one opinion be more likely than the other.

Also, if homozygous spider is possible then the difference between seeing the first one and proving it through breeding should be a limited number of years. What I'm getting at is why should everyone have given up on ever seeing a visually different homozygous spider years and years ago yet still hold out so much hope for proving a non-visually different homozygous spider through breeding? I realize every spider doesn't get bred at two years, especially the females but when was spider declared dominant anyway?

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someone correct me if im wrong, but i think the spider was declared dominant because there is not a visual super form. its the same as the pinstripe. The date this was "agreed" on, i have no idea :(

I dont think hom spyders are a lethal combination, but i do think we need more information on it.

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Originally Posted by RandyRemington

Don't mean to give you a hard time, but: isn't it just as much speculation that there might be a homozygous spider as that spider might be homozygous lethal? No one seems to have any good proof of either so why would one opinion be more likely than the other.

Also, if homozygous spider is possible then the difference between seeing the first one and proving it through breeding should be a limited number of years. What I'm getting at is why should everyone have given up on ever seeing a visually different homozygous spider years and years ago yet still hold out so much hope for proving a non-visually different homozygous spider through breeding? I realize every spider doesn't get bred at two years, especially the females but when was spider declared dominant anyway?

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Well, the reason I think it is more likely that homozygous spiders exist than that homozygous spider is lethal is because I've heard credible rumors of the first, and nothing but speculation of the 2nd. There is a member on this forum who claims to own a spider that has only been bred a fairly limited number of times, but so far has produced 100% spider offspring. I have absolutely no reason to doubt that claim. I've also heard 2nd or 3rd hand of some others who have been bred quite a bit more and still throw 100% spiders. Now, I realize this proves nothing, which is why I said I believe this possibility over the other one, rather than saying this is a fact.

It would be an easy enough thing to get pretty convincing proof if either one big breeder or a group of smaller breeders would pair known het spider to known het spider (or spider combos would work as well of course), and document the offspring ratios. 3/4 spider means it is non-lethal dominant with no visible homozygous form, 2/3 spider means it is co-dominant with a lethal homozygous form.

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Originally Posted by cinderbird

someone correct me if im wrong, but i think the spider was declared dominant because there is not a visual super form. its the same as the pinstripe. ...

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I guess my point was that there are only a few more years of breedings failing to produce a visual super spider than breedings failing to prove a homozygous spider. Just seems odd to me that so many people take it as a fact that there isn't a different looking super spider but still consider the idea that there isn't a homozygous spider at all very unlikely when they are almost exactly the same thing, the very difficult task of trying to prove something through it's absence.