Possible het's

[jhall1468]

True, but that means 75% probability that AT LEAST 1 is het (50% + 25%)

Oy vay, you are indeed correct.
My earlier numbers read:

Both Normal = 25%
Both Het = 25%
One het, one normal = 50%

When they should have been:

Both Het or Both Normal = 25%
One het, one normal = 75%

Feeling a bit sheepish now .

Now, let's try it with 3 hets:

P(A and B and C) = P(.5) * P(.5) * P(.5)

In this case you have a 12.5% chance of all three being the same (3 hets or three normals). Or, have a 87.5% chance of at least 1 being het.

4 hets:

P(A and B and C) = P(.5) * P(.5) * P(.5) * P(.5)

6.25% chance of them all being the same or a 93.75% chance of at least one het.

[hoo-t]

I'm by no means an expert, but I believe your original numbers are correct.

Both normal 25%
Both het 25%
one het, one normal 50%

The same distribution applies when breeding a het to het -

normal (both genes normal) 25%
homozygous (both genes morph) 25%
het (one normal gene, one morph) 50%

The problem is interpreting "AT LEAST ONE" in the original question.

"AT LEAST ONE" includes BOTH possibilities: "both hets = 25%" AND "One het, one normal = 50%". So you must add the two together to get the probability of "AT LEAST ONE". 25% + 50% = 75% probability of AT LEAST ONE het.

Right????
Steve

[hoo-t]

To add to my previous post, I think your calculations are working properly, but you have an incorrect assumption. You are assuming that you are calculating the probability of both being the same. In reality, you are calculating the probability of there being NO hets. In the sample of 4, there is a 6.25% probability that you get NO hets, leaving a 93.75% probability of AT LEAST ONE, which includes 1, 2, 3, 4, 5, or 6 hets.

Steve

[Kizerk]

imo, the more possible hets you get from the same clutch, the greater chances you have of one of them being het

[jhall1468]

I'm by no means an expert, but I believe your original numbers are correct.

Both normal 25%
Both het 25%
one het, one normal 50%

The same distribution applies when breeding a het to het -

normal (both genes normal) 25%
homozygous (both genes morph) 25%
het (one normal gene, one morph) 50%

The problem is interpreting "AT LEAST ONE" in the original question.

"AT LEAST ONE" includes BOTH possibilities: "both hets = 25%" AND "One het, one normal = 50%". So you must add the two together to get the probability of "AT LEAST ONE". 25% + 50% = 75% probability of AT LEAST ONE het.

Right????
Steve

Yes, that is correct. I realized my mistake after reading this thing 100 times and finally figuring out I simply forgot to add the two that had hets .

To add to my previous post, I think your calculations are working properly, but you have an incorrect assumption. You are assuming that you are calculating the probability of both being the same. In reality, you are calculating the probability of there being NO hets. In the sample of 4, there is a 6.25% probability that you get NO hets, leaving a 93.75% probability of AT LEAST ONE, which includes 1, 2, 3, 4, 5, or 6 hets.

I'm actually calculating the probability that all animals will be the same (all hets or all normals) and the probabilities I listed show (in your example) a 6.25% probability of their either being ALL hets or ALL normals. Which, it obviously follows that subtracting .0625 from 1.00 will give you the total probability of the original equation (all hets or all normals) NOT being true (which, as you stated, would be having a distribution of 1+ normals and 1+ hets).

The irony in all this, I'm currently working on a project where given a set of visitor demographics, our equation is to determine the likely "peak times" of customer trends (purchasing, calling the number, contacting support, etc). And yet, I screwed up (twice no less) on a simple independant probability equation . Too many statistics for one day me thinks.

[Adam_Wysocki]

imo, the more possible hets you get from the same clutch, the greater chances you have of one of them being het

That's not true ... a possible het is a possible het ... period. You have the exact same chances of proving or not proving 3 female possible hets whether they all come from the same clutch or from 3 different clutches ... Psycholigically, it "feels better" to have all the girls from a clutch for example, but in reality it gains you no advantage what so ever.

I've been producing, buying, and proving possible hets for many many years and the key is quantity ... nothing more.

-adam

[aaajohnson]

I've been producing, buying, and proving possible hets for many many years and the key is quantity ... nothing more.

-adam

Bingo ... and statistically speaking that can be proven .....

Neil

[elevatethis]

Statistics suck...but useful in any discipline...we're breeding snakes for crying out loud, and all those core statistical concepts still manage to creep in...

good info guys!

[hoo-t]

Yes, that is correct. I realized my mistake after reading this thing 100 times and finally figuring out I simply forgot to add the two that had hets .



I'm actually calculating the probability that all animals will be the same (all hets or all normals) and the probabilities I listed show (in your example) a 6.25% probability of their either being ALL hets or ALL normals. Which, it obviously follows that subtracting .0625 from 1.00 will give you the total probability of the original equation (all hets or all normals) NOT being true (which, as you stated, would be having a distribution of 1+ normals and 1+ hets).

The irony in all this, I'm currently working on a project where given a set of visitor demographics, our equation is to determine the likely "peak times" of customer trends (purchasing, calling the number, contacting support, etc). And yet, I screwed up (twice no less) on a simple independant probability equation . Too many statistics for one day me thinks.

When I posted, I was rushing to get out the door to go to work. But, as I was thinking about your post, I realized that you had answered my question about diminishing confidence. I just now got home from work, and I still gotta think about it some, but I know the answer is there!

Steve

[hoo-t]

Statistics suck...but useful in any discipline...we're breeding snakes for crying out loud, and all those core statistical concepts still manage to creep in...

good info guys!

Its amazing, when I was taking statistics type classes, I figured I'd never, ever use it. Now here I am! And while I found biology as a whole very interesting, I never paid a whole lot of attention to genetics. Punnett squares? I didn't even THINK about them again until my kids needed help with their school work. Now I'm fascinated enough with genetics, that I'm trying to learn which traits are dominant/recessive in rats and mice! Who cares what color the snake food is? Well, for one, I do!!!!

Steve