• Responding to email notices you receive.
    **************************************************
    In short, DON'T! Email notices are to ONLY alert you of a reply to your private message or your ad on this site. Replying to the email just wastes your time as it goes NOWHERE, and probably pisses off the person you thought you replied to when they think you just ignored them. So instead of complaining to me about your messages not being replied to from this site via email, please READ that email notice that plainly states what you need to do in order to reply to who you are trying to converse with.

  • IMPORTANT! PLEASE READ!! About the Google Adsense ads being displayed

    =====================
    Posted 08/15/2025
    =====================


    Yeah, I know. They are a pain in the butt. But they pay the bills to keep my server running. Just a fact of life, I am afraid.

    Want to get rid of them? Simple. Just become a Contributor level member or above and they will be gone. -> Please click HERE."

    Is that too much for me to ask of you to keep this site running? Well, sorry about that. I too wish I could get everything for free. But alas.....

    =====================
    Addendum: 01/10/2026
    =====================


    Google Adsense ad revenue for December, 2025 was just $30 over the cost of the lease for the server running this site. So, in effect, the money providing the incentive for me to continue running this site is coming SOLELY from the paid memberships and sponsorships here. Which honestly ain't much....

Double Recessive Genetics

A

A_Kendergirl

AKA Grinning Geckos
Joined
Apr 20, 2005
Messages
1,475
Reaction score
0
Points
0
Age
46
Location
Chicago
Next year I am planning on working with LVPAs. I'll end up making a lot of hets (they will all be 100% hets), but what I'm wondering is for the 2nd year of breeding. Let me know if I have this correct.

If I breed my hets together I should have the following:
1/16 chance of a LVPA
1/4 chance of a LV 66% het PA
1/4 chance of a PA 66% het LV
and the rest will be 66% het LVPA

If I breed a het back to a LVPA then I should produce the following (and this is where I get really confused!):

1/2 chance of an LVPA (or is it 1/4?)
ugh...I'm already confused... :dunce:

I can't figure out the chances, but it seems like I should get a good number of LVPAs, LV 100% Het PA, PA 100% Het LV, and any "normals" would be 100% Het LVPA.

HELP!! :slamit:
 
It would be 1/4th.

Let me see if this comes out:

p = patternless
P = normal pattern
a = alibino
A = normal color

From the patternless albino you can only get: p & a since they are ppaa
From the double hets which are genetically PpAa, there are four possible combinations: pa, Pa, pA & PA

Crude Punnett's square (the sperm / eggs only have a single copy of each gene, their genotypes are down the top and left side, the offsprings' genotypes are in the center):

.....pa......Pa.....pA.....PA
pa ppaa pPaa ppAa PpAa

pa ppaa pPaa ppAa PpAa

pa ppaa pPaa ppAa PpAa

pa ppaa pPaa ppAa PpAa
 
To answer your first question, you're right that it's a 1 in 16 for the double het pairing.

I'm a genetics idiot...this is why I do better understanding selective breeding. This is my thought process for selective breeding - pretty + pretty = probably pretty! That's pretty simple. :)

For everything else, I use Google.

Geckos Etc Steve Sykes Double Recessive Genetics

or, the somewhat more complicated, but interactive fun for the whole family - Genetics Wizard

Good luck with your project.
 
A_Kendergirl said:
Next year I am planning on working with LVPAs. I'll end up making a lot of hets (they will all be 100% hets), but what I'm wondering is for the 2nd year of breeding. Let me know if I have this correct.

If I breed my hets together I should have the following:
1/16 chance of a LVPA
1/4 chance of a LV 66% het PA
1/4 chance of a PA 66% het LV
and the rest will be 66% het LVPA
Click to expand...
Sorry, not correct.

I'm not up on leopard gecko genetics, but I've done plenty of genetics in other species. The real statistical results from a mating of two animals that are double hets for recessive mutant genes would be
9/16 normal (66% probability heterozygous albino and 66% probability heterozygous patternless)
3/16 albino (66% probability heterozygous patternless)
3/16 patternless (66% probability heterozygous albino)
1/16 albino patternless (LVPA?)

Please note that the normals from this mating are 66% probability heterozygous albino and 66% probability heterozygous patternless. That does NOT translate into 66% heterozygous LVPA.

I also check Alice's Punnett Square for the double het backcrossed to the patternless albino.
 
This is making my head hurt...but I think I understand. Thank you for the correction Paul, but for me, 1/4 is close enough for my purpose. I'm just trying to decide which route I want to go - het x het or homo x het. After figuring this out, I'll be going with the homo x het. However - if I make a genetics page on my website, I'll be sure to have up the correct stats.
 
I would make the same choice if space is limited. But I'd keep a couple of double hets for backup in case the LVPA died. Good luck.
 
Shanti, you're right that you will have more immediate results starting off with at least one homozygous individual. I'd suggest learning how to do a Punnett square for two traits (16 squares) so that you can determine what the offspring may be no matter what combo your have (Aapp x aaPp for example).

The genetics pages here:http://www.vmsherp.com/LCGenetics201.htm are also helpful and will explain how the Punnett square works. The hardest part is figuring out how to place the alleles along the empty squares when beginning. It is hard to explain without pointing & figures, but the trick that seems to help my students remember is this:

Starting with one parent (say the one you'll put along the top four columns) using your double het example AaPp. Each gamete (egg or sperm) will contain one allele for each trait (so, one 'a' and one 'p'). There are 4 possible combinations. To find them, start with the first A. You can pair it with the first P or the second p (first with the first, first with the second). Then move to the second a. Pair that with the first P and the second p (second with the first, second with the second). So you end up with AP, Ap, aP, ap. Using this method you know you have all the possible combos. Then take the second parent, do the same thing for the four columns down the side. Then you can fill in the squares to see exactly what you can expect - like Aliceinwl posted for AaPp x aapp.

Hope this helps! :) In my experience setting up the Punnett square is the toughest part for people to figure out.

Nancy
 
LOL...I learned the Punnett Square in Biology during 9th grade. I even remember doing double recessive traits. I just couldn't remember how I was suppose to split the allele. How was I suppose to know 10 years ago that I would actually want to use that knowledge someday!
 
If anyone wants some real fun, you can figure out a Punnet square for a Giant Mack Snow Albino Patternless from hets (if such a thing is even possible!) Playing with all those co-dom and recessive traits should be something else. And I think I'm just nerdy enough to try it. Time waster - here I come!
 
Ok...so I started working on it, then I cheated and used the link Rob supplied. Let's just say it's fairly ridiculous! I was able to figure out 16 of 256 possibilities before I decided I don't have THAT much time to waste. BTW, if you are wondering why I'm wasting time, and not painting, it's because I'm waiting for the darned A/C guy, who still hasn't shown up!
 
Sometimes reality and probability don't match up. This year, I bred a rainwater PA to a rainwater het patternless. Statistically, half the babies should have been PA's. So far from the pairing, I've hatched 2 PA's and 7 albinos...

-Alice
 
Yea...kinda sucks huh? It's a roll of the dice every time. Eventually, with enough hatchings, it should even out.
 
nwheat said:
I'd suggest learning how to do a Punnett square for two traits (16 squares) so that you can determine what the offspring may be no matter what combo your have (Aapp x aaPp for example).

The genetics pages here:http://www.vmsherp.com/LCGenetics201.htm are also helpful and will explain how the Punnett square works.
Click to expand...
I prefer the branching system, which takes me about have the time as for a equivalent Punnett square.

That URL did not work for me, though I finally managed to get to it roundabout. Here is another, similar site. http://www.cabinsoftware.biz/Genetics_Tutorial/Part1.htm
 
i suggest using genetics wizard for figuring out complicated genetics problems.

heres the answer for crossing a giant mack snow het for albino and patternless X another giant mack snow het for albino and patternless.


Het. albino, Het. giantc, Het. mack snowc, Het. patternless,
x
Het. albino, Het. giantc, Het. mack snowc, Het. patternless,






0.39% WT
0.78% Het. patternless,
0.39% Homozygous patternless,
0.78% Het. mack snowc,
1.56% Het. mack snowc, Het. patternless,
0.78% Het. mack snowc, Homozygous patternless,
0.39% Homozygous mack snowc,
0.78% Homozygous mack snowc, Het. patternless,
0.39% Homozygous mack snowc, Homozygous patternless,
0.78% Het. giantc,
1.56% Het. giantc, Het. patternless,
0.78% Het. giantc, Homozygous patternless,
1.56% Het. giantc, Het. mack snowc,
3.12% Het. giantc, Het. mack snowc, Het. patternless,
1.56% Het. giantc, Het. mack snowc, Homozygous patternless,
0.78% Het. giantc, Homozygous mack snowc,
1.56% Het. giantc, Homozygous mack snowc, Het. patternless,
0.78% Het. giantc, Homozygous mack snowc, Homozygous patternless,
0.39% Homozygous giantc,
0.78% Homozygous giantc, Het. patternless,
0.39% Homozygous giantc, Homozygous patternless,
0.78% Homozygous giantc, Het. mack snowc,
1.56% Homozygous giantc, Het. mack snowc, Het. patternless,
0.78% Homozygous giantc, Het. mack snowc, Homozygous patternless,
0.39% Homozygous giantc, Homozygous mack snowc,
0.78% Homozygous giantc, Homozygous mack snowc, Het. patternless,
0.39% Homozygous giantc, Homozygous mack snowc, Homozygous patternless,
0.78% Het. albino,
1.56% Het. albino, Het. patternless,
0.78% Het. albino, Homozygous patternless,
1.56% Het. albino, Het. mack snowc,
3.12% Het. albino, Het. mack snowc, Het. patternless,
1.56% Het. albino, Het. mack snowc, Homozygous patternless,
0.78% Het. albino, Homozygous mack snowc,
1.56% Het. albino, Homozygous mack snowc, Het. patternless,
0.78% Het. albino, Homozygous mack snowc, Homozygous patternless,
1.56% Het. albino, Het. giantc,
3.12% Het. albino, Het. giantc, Het. patternless,
1.56% Het. albino, Het. giantc, Homozygous patternless,
3.12% Het. albino, Het. giantc, Het. mack snowc,
6.25% Het. albino, Het. giantc, Het. mack snowc, Het. patternless,
3.12% Het. albino, Het. giantc, Het. mack snowc, Homozygous patternless,
1.56% Het. albino, Het. giantc, Homozygous mack snowc,
3.12% Het. albino, Het. giantc, Homozygous mack snowc, Het. patternless,
1.56% Het. albino, Het. giantc, Homozygous mack snowc, Homozygous patternless,
0.78% Het. albino, Homozygous giantc,
1.56% Het. albino, Homozygous giantc, Het. patternless,
0.78% Het. albino, Homozygous giantc, Homozygous patternless,
1.56% Het. albino, Homozygous giantc, Het. mack snowc,
3.12% Het. albino, Homozygous giantc, Het. mack snowc, Het. patternless,
1.56% Het. albino, Homozygous giantc, Het. mack snowc, Homozygous patternless,
0.78% Het. albino, Homozygous giantc, Homozygous mack snowc,
1.56% Het. albino, Homozygous giantc, Homozygous mack snowc, Het. patternless,
0.78% Het. albino, Homozygous giantc, Homozygous mack snowc, Homozygous patternless,
0.39% Homozygous albino,
0.78% Homozygous albino, Het. patternless,
0.39% Homozygous albino, Homozygous patternless,
0.78% Homozygous albino, Het. mack snowc,
1.56% Homozygous albino, Het. mack snowc, Het. patternless,
0.78% Homozygous albino, Het. mack snowc, Homozygous patternless,
0.39% Homozygous albino, Homozygous mack snowc,
0.78% Homozygous albino, Homozygous mack snowc, Het. patternless,
0.39% Homozygous albino, Homozygous mack snowc, Homozygous patternless,
0.78% Homozygous albino, Het. giantc,
1.56% Homozygous albino, Het. giantc, Het. patternless,
0.78% Homozygous albino, Het. giantc, Homozygous patternless,
1.56% Homozygous albino, Het. giantc, Het. mack snowc,
3.12% Homozygous albino, Het. giantc, Het. mack snowc, Het. patternless,
1.56% Homozygous albino, Het. giantc, Het. mack snowc, Homozygous patternless,
0.78% Homozygous albino, Het. giantc, Homozygous mack snowc,
1.56% Homozygous albino, Het. giantc, Homozygous mack snowc, Het. patternless,
0.78% Homozygous albino, Het. giantc, Homozygous mack snowc, Homozygous patternless,
0.39% Homozygous albino, Homozygous giantc,
0.78% Homozygous albino, Homozygous giantc, Het. patternless,
0.39% Homozygous albino, Homozygous giantc, Homozygous patternless,
0.78% Homozygous albino, Homozygous giantc, Het. mack snowc,
1.56% Homozygous albino, Homozygous giantc, Het. mack snowc, Het. patternless,
0.78% Homozygous albino, Homozygous giantc, Het. mack snowc, Homozygous patternless,
0.39% Homozygous albino, Homozygous giantc, Homozygous mack snowc,
0.78% Homozygous albino, Homozygous giantc, Homozygous mack snowc, Het. patternless,
0.39% Homozygous albino, Homozygous giantc, Homozygous mack snowc, Homozygous patternless,

enjoy that project....lol!
 
What everyone said so far is great, but for those of you using punnett squares - which I personally prefer because an empty box is harder for me to miss than a branch - do you remember the first, outside, inside, last multiplication order from middle school math?
(a*b)(c*d)=ac+ad+bc+bd

I find that rule pretty helpful with the squares because you're still multiplying across in order, here's something to illustrate from my notes(double hets assumed):

doublehet.jpg
 
Herpcam said:
To answer your first question, you're right that it's a 1 in 16 for the double het pairing.

I'm a genetics idiot...this is why I do better understanding selective breeding. This is my thought process for selective breeding - pretty + pretty = probably pretty! That's pretty simple. :)

For everything else, I use Google.

Geckos Etc Steve Sykes Double Recessive Genetics

or, the somewhat more complicated, but interactive fun for the whole family - Genetics Wizard

Good luck with your project.
Click to expand...
I like this way of thinking... forget the Punnett square!
 
Dan, were you bored? I just realized this thread is over 2 months old before you dug it back up! LOL... its an interesting thread though and I think I now need a few Tylenols and a bottle of Jack.
 
Back
Top