Reptile & Amphibian Forums

Sorry to bring this up again, but I never got back to it after my first post and now it is buried. So...

I was the first poster to a thread last week when someone asked about 25% and 33% possible hets. I answered that there was no such thing and I got my butt reamed. Someone even suggested that I learn about homozygous and heterozygous traits and maybe take a genetics course. I thought that was kind of funny since I have a Ph. D. in genetics. Paul Hollander did a better job of explaining it than me but some people still did not get it. I will try again.

There is no such thing as a 25% possible het! As Randy Remington suggested, this is a good designation for animals that come from a 50% pos. x 50% pos. cross, but it is NOT a probability. Here is why.
50% Possible hets don't exist either. That number is a probability, not an outcome. As each breeder tries to prove later on through breeding trials, a 50% possible het is either PROVEN to be normal (0% het), or proven to be a 100% het. It cannot be proven to be a 50% het.

Therefore, 50% possible het x 50% possible het crosses, once the animals are proven to be either normal or true 100% hets will look like this:
100% x 100% = homozygous animals and 66% hets
100% x 0% = 50% possible hets
0% x 100%= 50% possible hets
0% x 0%= 0% hets

Nowhere in those crosses do you get a 25% or 33% het.

I agree that calling an animal a 25% possible het will let you know that two 50% possible hets were crossed, but this number is NOT the probability that you will get a het out of that cross. The actual probability, as shown above is either higher, or 0.

I hope this is a bit clearer to some of you, and I'm sorry for the confusion I caused in my original three sentence answer.

Thank GOD someone finally said what i have been mulling over in my mind... I have been asking myself and others... if you breed a labeled 50% het and it proves out, wouldnt it automatically become a 100%? To the term 50% or any other % is in reality a Term for a normal appearing snake that may in the end have the POSSIBILITY to be 100% het. Its a gamble, and also a great way to get a "little extra" money from people that dont necessarily know any better. It seems you tack on a percentage, then 66% would look WAY better than a 50%. In the end, you could buy two "66% labeled" snakes and end up with nothing other than a bunch of baby normals (which is good too) and have absolutely no recourse because you actually spent the money on a 66% CHANCE that it is either 0% or 100%. Maybe i have been figuring this all wrong... I am in all actuality only a firefighter, and by no means a Genetics wizard, so Please correct me, But isnt a Het either a HET (100%) or Not (0%)???

yes, that is true, it is either 100% or 0%. You are playing the odds, but with a 66% possible het, the odds are in your favor. I don't buy possible hets because I am not a gambler, but the possibility also exists to win big with them.
Another myth to dispell is that buying multiple hets only increases your odds if you buy them all from the same clutch. Not true. If you want heads, it doesn't matter if you flip 1 dime, 1 nickel, and 1 quarter, or 3 dimes. All will have the same probability of coming up heads. The probability of successfully getting a 100% het from buying a 50% het increases for every het you buy, but it doesn't matter what clutch the hets come from. Individually they all have the same 50% probability of being a 100% het.

Thats what i have been thinking.... I'm not much for gambles either.. thats why i dont get Hets either. If i do get somehting, it would be a Pastel, which, from my understanding is a Het form. There arent any 66% het for Pastel... it either is or it isnt. You breed a normal to a pastel, you either get normal or you get Pastel... nothing else. No 33%, no 50%, no 66% it either shows the traits from the pastel which would make it Pastel or be plain old normal... As i said in my last post, i dont claim to know anyhting at all, so corrections are always welcome, but the whole "Het" term is very confusing to people that are new to the Hobby. If i had a dollar for every show that i have been to that someone told me "here, you buy these two snakes that are both 66% het and breed them, you are guaranteed to get "BLAH"" I mean, it is definitely misleading.. I wouldnt buy anything other than a proven 100% Het... Also... I ahve been seeing people selling 100% het snakes... and they are babys... how can you prove that it is 100% as a baby... I thought to prove it as a Het you have to breed it... maybe I am wrong

If you breed a homozygous recessive, like an albino, to a normal animal you will get all 100% hets. This is because the homozygous albino animal has the albino mutation on both chromosomes carrying the mutant gene and can thus only pass the mutant gene on to its offspring. The normal can only pass a normal gene. Therefore, all offspring will have one mutant copy and one normal copy making them 100% hets.

Hmm ok, thought i had it... I think i jsut fried my Firefighter brain there... maybe i should stick to dragging hose. So in the case you just presented, where would the 50% Hets for albino and what not come from? If all are 100% het from a normal / albino pairing.. Is it jsut Albin that are like that or are there others? Maybe you could give me a good site address so i can go study this... My brain is melting and i need to see it all out there in writing. lol thanks..

Now I could be way off here, if I am 1st sorry,2nd let me know.

I have allways thought 25%,and 33%, het were from breeding more then just one morph.

I'll use burms as an expanple cause thats what I know. It will be the same with balls.

If you were to breed an albino het lab, to a green het albino, you would get alot of 25% hets, here is the out come;

The Genetics Wizard's Answer, 3 Genetic Traits
Het. is Heterozygous. WT is Without Trait or Wild Type.
Homozygous albino, Het. lab,
x
Het. albino, Homozygous green,

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25% Het. albino, Het. green,
25% Het. albino, Het. lab, Het. green,
25% Homozygous albino, Het. green,
25% Homozygous albino, Het. lab, Het. green,

Now yes the snakes will either be het or not, but at the same time you would call them 25% hets, till you PROVE otherwise.

So yes there are 25% hets, but from the little I know, it's only possible if your breeding more then one morph.

Now if I'm wrong let me know, but that came right from the Genetics Wizard, so if I'm wrong so are they.

You get 50% possible hets when breeding a normal ball python with a 100% het animal. Half the offspring will be normal, the other half will be carrying the recessive gene. Hence each offspring as a 50% change to be carrying the recessive gene.

66% Possible hets are creating when breeding two 100% het animals. In this pairing, out of three normal looking offspring, only two would carry the recessive gene, thus each normal offspring would have a 66% possible chance of having the recessive gene (the four in a 4 egg clutch would show the recessive gene morph)

100% hets are both confirmed hets due to proving them out via breeding, or babies from a morph and normal parent. The dominate wild type gene will always wind up being pared with the recessive morph gene, hence 100% hets.
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PHLdyPayne

Go to NERDS website. They list all the mutations that they work within the photogallery and tell what type of mutation it is. Also they have three short papers on genetics that are very informative and pretty simple to read. You should get a better understanding of it all afterwords...lol...Hope this helps, Todd

I think there still is some genuine confusion where people apply the punnett square to clutches rather than each egg and really think the odds are better buying an entire clutch of possible hets together. However I also think some of it was also in response to the het pied marker and it was a way of making a random pick of possible hets (the clutch) to help the breeder avoid the entanglement of having to pick possible hets for the buyer who didn't yet know about the sporadic marker.

np
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Isn't it cooler that serpent's don't walk anymore?
(Genesis 3:14)

Its my Male Brazilain Rainbow Boa...

and a very nice looking brazilian rainbow he is too.
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PHLdyPayne

Thank you.

np
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Isn't it cooler that serpent's don't walk anymore?
(Genesis 3:14)

>>Its my Male Brazilain Rainbow Boa...
>>

Beautiful.....
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Arafura Filesnake

Chinese Watersnakes

I don't think anyone is saying that a 25% het has 25% of his genetics being a het. Obviously, a 50% het is actually breeding either a 100% or 0%, but nothings PROVEN. If 50%ers are bred w/o having proven anything out, calling them 25% hets IS accurate! Yes, technically, they're either 100% or 0%, but its a way of letting people know that 2 unproven, possible hets were bred together. It's useful to let them know and you sell them at or right above normals, knowing there's a CHANCE they are hets. I don't know what all the fuss is about!
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Isn't it cooler that serpent's don't walk anymore?
(Genesis 3:14)

It isnt a Fuss for me... I am just trying to get it all straight in my mind. I think it comes down to the fact that there are unethical people that sell snakes as Hets to get more for thier normals even though they know that they are normals.. It is just a little confusing to newbies to the Hobby

The problem is that some people DO think that a 25% het. is a possible outcome rather than a designation, and others purchase them without understanding what the difference between a probabilty and an outcome is.
I'm just trying to help others understand an issue that seems to be as clear as mud to some people.

See, I ain't even a fire fighter . The fact is, no matter what % possiblity it is, it's still only a possibility. I'm sure some out there know someone whos bred 66%ers and not gotten a visual out of a clutch. And on the other end of the spectrum, there must be some out there who've bred 25%ers and Gotten a visual. Maybe even the first try. It's all a moot point to me. It either is or it isn't het, and it MUST be proved out to find out. So in closing I'd just like to say "Ya either got it or ya ain't," It's up to the GODS. The percentages is just a selling point.

Quig

you took the words right out of my mouth. lol

Anyone seriously wanting to breed ball pythons should know at least enough about basic genetics to know a 25% possible het albino is not going to produce 25% of its clutch as albinos. If they haven't figured that out, maybe they shouldn't be breeding yet.
Hypothetical situation. Someone has a 50% het albino pair that he breeds. He gets all normals so sells them off as normals, I bought a female off him as a normal. I take my normal and breed her to my Pied male to produce het pieds. Now in the years that it took me to get her up to size to breed to my pied male the original breeder proved out that his 50% were 100% hets. A couple years after breeding my female to a pied I decide to pair her up with an albino expecting some hets and instead get a couple albinos in the clutch. Meanwhile all of her offspring have been sold as het pieds when they were all possible double hets for albino and pied.
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Nita Hamilton
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Ball Pythons
ballpythonworld.com

That's cool if everyone's just trying to get it straightened out in their heads. There are some that argue it b/c "a 25%er doesn't really exist, so therefore I must argue the point." It's annoying at times when people on the forums will jump on ANYTHING just b/c they can. Most of the "flaming" on the forums are over technicalities of words that neither the original poster intended or the responders believe they intended. They just want to be proven right...(much like this post, ironically).
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Isn't it cooler that serpent's don't walk anymore?
(Genesis 3:14)

Without having proved one or both of the 50% hets that were bred - there is no way to precisely indicate what the percentage is - it is still possible that one of them is an actual het or neither could be or they both could be but didn't hit the odds. Personally I would never cross two 50%ers in the first place. But there has to be some kind of legitimate indication as to the possiblity of the het gene being passed on from such breedings were the parents did not prove. I've always thought that a 25%er meant that it was from a 50%er to a normal. Maybe we could re-name the 50% x 50% to 24% - LOL. But does it really make that much difference 9 times out of ten they are priced the same as normals anyway - the added bonus of possibly somewhere down the line proving the gene is there is just a perk.
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Tosha

"Nihil facimus sed id bene facimus"

7.33.0 Ball Python (Harry and Fluffy and gang)
1.0.0 Angolan Python (Anakin Skywalker)
0.0.1 Green Tree Python (Verdi - yeah I know but my kids love the book)
0.2.0 Feline (Pippen and Pandora)
0.0.1 Desert Tortoise (Pope John Paul aka JP )
2.2.1 Fish (1,2,3,4)
0.0.2 frogs rescued from pool skimmer

I say call em all 50%... no confusion at all there... It might have gene... might not... breed it and see. If it proves, great, if not... oh well, you have a normal... still not a bad thing

"I've always thought that a 25%er meant that it was from a 50%er to a normal."

Me too. I guess I hadn't thought much about what to call the offspring when 50% het X 50% het don't prove. Seems like if you where going to try to put a % on that cross it would be very complicated and depend on how many normals you had produced.

So, if "25% het" doesn't have an excepted meaning much less agreement that it's the best probability we can assign then it probable isn't a good term. How about "possible possible" het for the offspring of 50% het X normal?

Yeah,that would be the only way to fairly advertise them.

(i hatched six pph for caramel females this year,and they are not going anywhere )
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Charles Glaspie

Tanstaafl:
"There ain't no such thing as a free lunch".
An acronym created by my favorite author Robert A. Heinlein.

If you breed to 100% hets of different traits together each offspring would be 50% possible het for both traits or 25% possible DHs.

I only bring this up because I have been considering breeding two different trait hets together just to 'dink' around. I have been trying to figure out some 'odds' of what can be produced....basically the chance and time it would take to prove out a DH pair from that breeding would be a while....but producing possible DHs will reduce the number of possible het bps that I will be raising up to breeding size to 'prove out' and my chances of having a het something in there are greater than with just one trait floating around. Hopefully if they dont prove out for one het...they will prove for the other. Since I keep a small collection I figure this would be best for me.

Just thought I would add my 0.02