het albinos

with a 25 % chance for albino, if your female has 4 to 8 eggs then you have a good chance of getting one. 25 % is per egg, but 4 eggs doesn't = 100 %, but more eggs betters your chances.

Hi,

Your not wrong on the math. :rage:

I asked a mathematician friend what the odds were of a female black pastel out of a clutch of 6 eggs.

Apparently it works out that the chance of a female black pastel in a 6 egg clutch is 6% but the chance of no black pastel females is 18% :confused: :confused: :confused:

I'm not so much number blind as thick and still can't get my head around that one. :taz:

I trust it to be true - I just don't understand probability well enough to know why. :(


dr del

Dr. Del,

I think that the reason your female pastel odds seem weird is dependent on what was asked of your mathematician friend. There is a difference between asking for the odds of 1 and ONLY 1 female black pastel vs. at LEAST 1 female black pastel or even 1 female black pastel and a few male pastels.

It should be logical that the odds for getting a female black pastel PLUS the odds for NOT getting a female black pastel should equal 100%. It is all in the subtleties of what is asked.

I'm not sure what was asked of your mathematician friend, but assuming that the odds of producing a black pastel is 1/4 (black pastel is recessive right?) then I THINK the odds work this way:

Your possible outcomes are Pastels, Non-pastel, Non-pastels, Non-pastels. We list three Non-pastels as potential outcome because there is 3/4 chance of non-pastels.

If we add gender, then we get M Pastel, F Pastel, M Non, F Non, M Non, F Non, M Non, F non so basically 8 different outcomes.

So per egg, you have a 1/8 chance of getting a female black pastel and 7/8 chance of not getting one.

Each egg is an Independent event, which means the outcome of one egg does not influence the outcome of another egg. For independent events if you are trying to calculate the odds of one thing AND another thing happening, you multiply the odds.

So the odds of getting NO female black pastels would be the odds of not getting a female black pastel on egg 1 AND egg 2 and egg 3... etc.

In equation form that looks like = (7/8)*(7/8)*(7/8) etc. etc. OR an easier way to write it would be Probability of NO female black pastels = (7/8)^n where n=total number of eggs, in this case 6

So in an 6 egg clutch, the probability of NO female black pastels at all should be (7/8)^6 = 44.9%

From that we can derive that the probability of at LEAST one female black pastel is = 100-odds of NO female black pastels or 100-44.9 = 55.1%

So in theory you can calculate the odds of at LEAST one female black pastel in an egg clutch by 1-(7/8)^n where n = number of eggs in a clutch.

Note that we do not calculate the odds of at LEAST one female black pastel by multiplying (1/8)*(1/8) so on etc. because that method would give us the probability of getting a female black pastel in every single egg (which by the way is very small odds, .000381%)

Rather calculating the odds of NOT getting a female black pastel and then subtracting from 100%, you can calculate the odds of a getting a female black pastel from the 1/8 number but the equation gets ugly fast the larger the number of eggs. I prefer to keep things simple.

For those that want to know the odds of getting say at least one albino regardless of sex out a given egg clutch, the equation is 1-(3/4)^(Number of eggs)

I think this is right, perhaps someone out there can verify or disagree with my math?

Hi,

I asked him and he says you are correct in the method used. :gj:

But black pastels are co-dominant so each egg has a 50% chance of being a black pastel and 50% chance of being female so the numbers for getting any female black pastels in a 6 egg clutch are;

(1-.75^6) x 100 which is 82.202% :banana: :banana:

He also walked me through how to work out the chances of the various combinations of sex and morphs in the whole clutch. My head hurts. :oops:

So I worked out the chance of getting 6 black pastel females was 0.024% :rolleyes:

Not holding my breath on that one. :rofl:

But my chance of getting any black pastels irrespective of their sex is a whopping 98.43%

Now them's good odds. :yes:


dr del

Ah yeah I didn't realize black pastels were co-dominant. I bet it does make you feel good that you have that high of a chance at a black pastel period.

I've got a pair of het albino ball pythons that are right at about a year old and so I was doing calculations to see what my odds were of getting an albino if/when I ever get them to breed. I was fairly encouraged.

Its just the luck of the draw!