I did a write up on the spider, double check it for me?

I need to take a genetics class...:( All this pheno whoknow idontknow stuff is hard to follow. So, recessive lethal. How do you prove that? Would it be just the fact of no super spider existing?

The only thing I don't get with the whole leathal theory is why are there not a lot of bad eggs with spider x spider pairings? I am sure NERD has done tons of Spider combo x spider combo clutches by now to make some of the crazy combos he makes. Unless he is just not reporting any egg death issues I don't see how this theory can hold up. The egg would not get the second spider gene until ovulation. That would mean something would have to come out of the female. Either a bad egg, or a good egg that goes bad during incubation. The point is that there would be evidence of an issue. So far I have not heard of a single person with proof of any leathality issues. The whole thing started from one persons conjecture and that is all it takes in this hobby. Same thing with the caramel females can't lay eggs thing.

Well I didnt mean to call you out lol, I was just under that impression so I double checked everything. Those errors were common little nothings that no one would noticed regularly.

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Originally Posted by LotsaBalls

I need to take a genetics class...:( All this pheno whoknow idontknow stuff is hard to follow. So, recessive lethal. How do you prove that? Would it be just the fact of no super spider existing?

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Taking biology classes is a wonderful idea! I highly encourage it for anyone in the hobby. Heck you don't even really need a class. Wikipedia (longer articles with plenty of references are best) and textbooks get you quite a ways on your own.

As far as proving recessive lethality.. with the jaguar trait in carpet pythons, it's easy. Hatchlings don't fully develop in the egg, and they die off before melanin production occurs. You get all-white baby snakes, dead in their eggs, that ALMOST go full term. It's worked out to be about on average 1/4 of a clutch is dead white snakes from a jag x jag breeding, so it's been inferred that the jaguar trait is homozygous-lethal.

There is less evidence of recessive lethality in spider ball pythons, but there are "guesses". The only real evidence that we have is that there SHOULD have been a homozygous spider produced if it was capable of being produced. On top of that, while we don't understand the exact relation between the presence of the spider trait and the neurological defects known as the "spider wobble", it really wouldn't surprise me that a relation between those defects and homozygous lethality exists.

While there are plenty of holes in the theory that the spider trait is homozygous-lethal (mostly due to lack of concrete evidence, which in itself is a pretty big hole), the lack of a homozygous spider existing poses some serious questions.

We're going to see this issue brought up in the next couple years a bit more I think. With the strong influx of large numbers of bumblebees, I think it's likely that we will see plenty of bumblebee x (spider combo) pairings in the not too distant future. Maybe we'll get more data and be able to form a theory better backed up by actual evidence rather than a lack of evidence.

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Originally Posted by J.Vandegrift

The only thing I don't get with the whole leathal theory is why are there not a lot of bad eggs with spider x spider pairings? I am sure NERD has done tons of Spider combo x spider combo clutches by now to make some of the crazy combos he makes. Unless he is just not reporting any egg death issues I don't see how this theory can hold up.

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That's the big question isn't it, what does Kevin have to say on this matter?

Anyone who breeds gets some amount of egg-death, so it's quite possible that egg death in spider x spider clutches is underreported, or not seen as an anomaly.

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Originally Posted by mainbutter

As far as proving recessive lethality.. with the jaguar trait in carpet pythons, it's easy. Hatchlings don't fully develop in the egg, and they die off before melanin production occurs. You get all-white baby snakes, dead in their eggs, that ALMOST go full term. It's worked out to be about on average 1/4 of a clutch is dead white snakes from a jag x jag breeding, so it's been inferred that the jaguar trait is homozygous-lethal.

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They hatch alive, then die right after, someone even had one live over night, but passed that day. it was pretty obvious it was the homozygous version of the jag, lucy carpet. carpets give you a bigger clutch size so its easier to see things like this compared to ball pythons also.

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Originally Posted by that_dc5

Well I didnt mean to call you out lol, I was just under that impression so I double checked everything. Those errors were common little nothings that no one would noticed regularly.

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hey no problem it needed to be proof read lol. im no english major (obviously)

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Originally Posted by Serpent_Nirvana

You're misunderstanding what that line means.

The line that you underlined was intended to clear up a completely different common misconception, which is that dominance is a function of the phenotype. Meaning, many people think that a more "intense" phenotype will dominate over a less "intense" phenotype. For example, some people might think that red is dominant to white because red is darker. I really don't know how to explain it better than that because it's an incorrect misconception, but that is what the author is driving at.

You ignored the first line of the Wiki article (emphasis added):

"Rather, the terms simply refer to the visible trait, the phenotype, seen in a heterozygote."

That is in the second line of the paragraph I linked to.

The fact of the matter is, though, that these terms are way too simple to adequately describe genetics as we now understand it. That's why geneticists keep expanding and adding new concepts, such as recessive lethality, and that's why it's such a pain to try and fit these complex genetic concepts into these overly-simplified categories.

I had one genetics professor who hated these terms (dominant, recessive, etc.) for that very reason.

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See no matter how many times i read it over, i still can't see it any other way. i mean point me out where i go wrong

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A dominant trait does not mean "stronger," and recessive does not mean "weaker." Rather, the terms simply refer to the visible trait, the phenotype, seen in a heterozygote.

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I understand this as, I'm going to call the albino gene recessive, because in the het form, i cannot see the phenotype. I don't call a super pastel recessive, i call it co-dom, because it is seen in the het form. The phenotype makes the gene described the way it is. which he says later on in the quote i posted before.

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If there are only two phenotypes, and a heterozygote exhibits one phenotype, by definition the phenotype exhibited by the heterozygote is called "dominant" and the "hidden" phenotype is called "recessive." The key concept of dominance is that the heterozygote is phenotypically identical to one of the two homozygotes. The homozygous trait seen also in the heterozygous individual is called the 'dominant' trait.

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I don't see any argument here

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It is critical to understand that dominance is a genotypic relationship between alleles, as manifested in the phenotype. It is unrelated to the nature of the phenotype itself.

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See i don't see anything about misconception, it is only stating how i already think

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, e.g., whether it is regarded as 'normal or abnormal,' 'standard or nonstandard,' 'healthy or diseased,' 'stronger or weaker,' or 'more or less' extreme. It is also important to distinguish between the 'round' gene locus, the 'round' allele at that locus, and the 'round' phenotype it produces. It is inaccurate to say that 'the round gene dominates the wrinkled gene' or that 'round peas dominate wrinkled peas.'

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Now we call them genes in the the reptile world, but would wouldn't lesser be one allele make a heterozygous, and a BEL have 2x lesser alleles.

If this is incorrect then what does the the previous statement mean and what exactly is the difference between the gene locus and allele. because I thought where the alleles physical hung out was called the locus, and the alleles were what we think of as morphs.

... Is it possible that the spider gene simply can't have a super? If Xx is the only kind of spider that will exist? Is there some way of a gene requiring there to be one of each (spider and normal ie: big X and a little x?) aside from recessive lethality? I'm not much of a genetics expert, so I'm not sure if that is a dumb question :D