Posted by:
rainbowsrus
at Mon Nov 5 12:36:10 2007 [ Email Message ] [ Show All Posts by rainbowsrus ]
Yeah the punnet square will work but get exponentially more difficult as you increase the number of morphs involved. I calculate the odds this way (and yeah, like everyone stated, single litters tend to not follow punnet rules):
first seperate the individual traits. taking you case a step further to show the ease, how about a DH snow x TH arabesque snow? Or one animal has one albino and one anery gene while the other has one albino, one anery and one arabesque gene.
Three traits, three factors:
Albino (recessive) het x het = 1/4 albino, 3/4 66% het albino
Anery (recessive) het x het = 1/4 anery, 3/4 66% het anery
Arabesque (dominant) het x normal = 1/2 arabesque, 1/2 normal
total phenotypical possible outcomes are the product of each factor. Possible albino phenotypes x anery phenotypes x arabesque phenotypes or 2 x 2 x 2 = 8
From here you can just calculate ythe one(s) you want or all, but have to use the phenotype factor (even if normal) to get the final odds for a given phenotype.
so, the gem would be Arabesque snow or arabesque x albino x anery = 1/2 x 1/4 x 1/4 = 1/32
works the same for any other phenotype
albino 66% het anery (not arabesque). Not arabesque x albino x 66% het anery = 1/2 x 1/4 x 3/4 = 3/32
This branching method can be used for any pairing no matter how complicated. For example, jungle het snow x hypo motley jungle het snow, what are the odds of a hypo, motley, super jungle, snow
5 traits, 5 factors
hypo x normal = 1/2 hypo, 1/2 normal
motley x normal = 1/2 motley, 1/2 normal
jungle x jungle = 1/4 normal, 1/2 jungle, 1/4 super jungle
het albino x het albino = 1/4 albino, 3/4 66% het albino
het anery x het anery = 1/4 anery, 3/4 66% het anery
total number of possible phenotypes is 2x2x3x2x2= 48 WOW
Odds of getting a hypo, motley, super jungle, snow are:
1/2 x 1/2 x 1/4 x 1/4 x 1/4 = 1/128
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Thanks,
Dave Colling
www.rainbows-r-us-reptiles.com
0.1 Wife (WC and still very fiesty)
0.2 kids (CBB, a big part of our selective breeding program)
LOL, to many snakes to list, last count:
24.36 BRB
19.19 BCI
And those are only the breeders 
lots.lots.lots feeder mice and rats  
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IMO, an easier method than punnet square - rainbowsrus, Mon Nov 5 12:36:10 2007
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