question about genetics

[Jeff876533]

hey ok i was looking on paul sages website (great leos by the way ) and one of the blizzards says 66% het. So does this mean that 66% of the offspring will be blizzard? if not, what does it mean? sorry if its a stupid question, like ive said before, im just starting out on genetics

 

[brandy101010]

It means the gecko has a 66% chance of being a het.

 

[Jeff876533]

i know but what exactly does het mean? does it mean like if it does breed, 66% of the hatchlings will physically look like a blizzard?**edit** o i think i know what it is now! lol so does it mean the hatchlings will have a 66% chance of looking like a normal?

 

[TripleMoonsExotic]

It means every gecko from a het to het pairing has a 66% possible chance of being het for the recessive mutation in question.

Example:

het Albino (1 allele) x het Albino (1 allele)
=
Albino (2 alleles)
&
Normals 66% possible het (1 allele) Albino
offspring

66% het is used because statistically 66% of the normal offspring should be het for the recessive mutation.
___________________

Fixed my boo-boo! That's what I get for posting in a rush during break time!

 

[gko reptiles]

First of all, het means that the gene for whatever recessive quality is present, but it is not expressed. Umm... look up Gregor Mendel's pea plant experiment, this should help you out with the explination that I'm about to provide! 66% het is an annoying term! Fortunately, Phillip and I were so mad about it one night, that we sat down and figured it out! Ok... so here we go... (pay attention... it gets kind of confusing!)

66% het means... (We'll use albino for example because it's an easy on/off recessive.)
A het albino (ie: Aa; which is a normal looking leo but it is het for alb.) is bred to another het albino (same as above). If there are 4 offspring, and everything goes the way that is "should" the offspring will be this: 1 albino (aa), 2 het albino (Aa), and one normal (AA). We know that the aa is albino, therefore it is eliminated from the equation. As for the other 3... we know that 2 of them will be het for albino Aa, and the other will be a normal AA; the problem here, is that all 3 of the other babies look the same! So, we take 100% of the normal looking babies and divide the "100"(percent) by 3 (babies) and get 33.333333333% (and round off to 33 naturally, because its the easiest thing to do!) So now, each baby is 33% possible het for albino. BUT 2 out of the 3 babies are het for albino, therefore, we take the 33% and multiply it by 2 (because we know that 2 of the babies are hets). THEREFORE *takes breath* the three babies have a 66% (33% x 2) chance for being het for albino. Now there's one problem left! We know that 2 of them are hets... but they all look the same, so which one is not het for albino? That's the part that we don't know! It's just a hope and pray situation that you got one of the hets, and not the normal! I hope that this helped I tried to explain it the best way that I could! Good Luck!

 

[TripleMoonsExotic]

I just noticed a boo-boo with what you said...

Percentages reflect the statistical probabilty of each egg, not the clutch as a whole. If you breed two geckos that are both normals het Albino, the resulting statistical probabilty will be as follows: 1/4 Albino, 1/4 Normal, 1/2 Normal het Albino. Disregard the Albinos as they are showing the trait and cannot be het for it, and you are left with all normals, some het for Albino and some not. Statistically 1/2 out of 3/4 of the normals will be het for Albino.

0.5 / 0.75 = 0.66667%.

That is the math behind how you get the 66% het.

:main_thumbsup:

 

[Jeremy Letkey]

It means every gecko from a homo to het pairing has a 66% possible chance of being het for the recessive mutation in question.

Example:

Albino (2 alleles) x het Albino (1 allele)
=
Albino (2 alleles)
&
Normals 66% possible het (1 allele) Albino
offspring

66% het is used because statistically 66% of the normal offspring should be het for the recessive mutation.

Steph, I know it was late and I'm not trying to nit pick... shouldn't your first sentence read

It means every gecko from a "het to het" pairing has a 66% possible chance of being het for the recessive mutation in question.

Homo to het would produce visuals(homo) and 100% het offspring.

I hate damn genetics lol. Can't we just put the pretty geckos together and get more pretty geckos. lol

 

[Dee]

I just noticed a boo-boo with what you said...

Percentages reflect the statistical probabilty of each egg, not the clutch as a whole. If you breed two geckos that are both normals het Albino, the resulting statistical probabilty will be as follows: 1/4 Albino, 1/4 Normal, 1/2 Normal het Albino. Disregard the Albinos as they are showing the trait and cannot be het for it, and you are left with all normals, some het for Albino and some not. Statistically 1/2 out of 3/4 of the normals will be het for Albino.

0.5 / 0.75 = 0.66667%.

That is the math behind how you get the 66% het.

:main_thumbsup:

I think she just said the same thing in layman's terms lol.

 

[TripleMoonsExotic]

Steph, I know it was late and I'm not trying to nit pick... shouldn't your first sentence read

It means every gecko from a "het to het" pairing has a 66% possible chance of being het for the recessive mutation in question.

Homo to het would produce visuals(homo) and 100% het offspring.

Correct! I corrected myself in the 2nd post! :main_thumbsup:

I hate damn genetics lol. Can't we just put the pretty geckos together and get more pretty geckos. lol

I wish! But then their would be SO many unanswered questions! I actually didn't know a darn thing about genetics until I got involved with Cornsnakes!

I think she just said the same thing in layman's terms lol.

I didn't see it that way. What I posted in the correct way that 66% het is figured.

It really isn't that hard...

75% of a clutch from a het to het pairing will be normal
50% of that 75% will carry the recessive allele
divide 50%/75%
equaling your statistical chances

 

[Grinning Geckos]

Ummmm....I actually do understand the genetics and all that was enough to confuse me....who knows what poor Jeff is thinking!! So...let me try to explain it in simple terms.

Het means they are carrying 1/2 of the genetic code needed for making a particular morph...in this case albino. No ifs, ands, or buts - the genetic material is there, but you can't see it.

I have to make a punnet square for this next part. We'll use "N" to represent the normal gene and "a" to represent the albino gene. One parent goes across the top, and one goes down the side. Remember - Het means they only carry 1/2 the code .... so they only get 1 a. Then you use it sorta like a multiplication chart...fill in the blanks going down and to the side. The four inside boxes represent your offspring. (Ignore the dots...I just used them for spacing)

.....l....N....l....a....l
----------------------

N...l...NN...l...Na...l
----------------------
a....l...Na...l...aa...l
----------------------

This reads as:

Of four babies, 1 will be totally normal (NN) and it will never be able to produce an ablino because there isn't the gene for the albino there.

Of four babies, 2 will be het for albino (Na) and they can make albino babies, but don't look like albinos thenselves.

Of four babies, 1 will be albino (aa).

(Please note...this is your statistical chances of hatching...not what actually will hatch)

That gives you 1 albino, 2 hets, and 1 normal. We're going to pretend like the albino doesn't exist now and just focus on the hets and the normal. That leaves you will 3 babies to worry about. The normal looks normal (of course)...but so do the hets. So how do you tell them apart? The problem is YOU CAN'T. All 3 babies look normal, but you know that statistically 2 of them carry the genetic material for albino.

SO

2 divided by 3 = 66%

What ALL of this boils down to is you have a 66% chance of that gecko carrying the gene for albino (meaning it can make albino babies)...but you ALSO have a 33% chance your gecko is completely normal and it will never make albino babies.

WHEW! I really hope that was easier for you to understand.

 

[TripleMoonsExotic]

You repeated exactly what I said but limited your scope to only 4 individual offspring. By useing precentages, you are not limiting that mind set.

75% of a clutch from a het to het pairing will be normal

You said 3 out of 4 would be normal...

50% of that 75% will carry the recessive allele

You said 2 out've the three would be het...
(when in truth, it's not two out of three but 66% of those three...Which we all know is impossible to technically split into an even number of offspring - and of course Murphy could give you a swift kick in the butt )

divide 50% by 75% equaling your statistical chances (66%)

 

[Golden Gate Geckos]

:stars: Got my head spinning!

 

[Grinning Geckos]

You repeated exactly what I said but limited your scope to only 4 individual offspring. By useing precentages, you are not limiting that mind set.


You said 3 out of 4 would be normal...


You said 2 out've the three would be het...
(when in truth, it's not two out of three but 66% of those three...Which we all know is impossible to technically split into an even number of offspring - and of course Murphy could give you a swift kick in the butt )

No, I wasn't really limiting it to just 4 offspring. I just stated things in a way that should be easier to grasp by someone who doesn't understand genetics. If you look again, I use 4 offspring to transition into percentages ... the way the babies look is much more tangible than just stating a number.

I will add to my previous post that these are the chances for each and every baby that hatches. If it's albino, you've got no problems knowing what you have. However, if it looks normal you don't know if it's het or actually normal .... BUT you're armed with the knowledge that 2 of 3 (or 2/3 if you prefer.....anyway you slice it, it's STILL 0.6666667 OR 66%) normal looking babies are het. So calling anything that hatches normal looking 66% het is an appropriate reflection of your chances it is a het in this situation.

PS - 66% of 3 is 2. What they really need to keep in mind is that these are just odds....and odds don't always work in your favor. You can buy 3 66% hets and you'll have a very good chance that at least 2 are actually het. If you're lucky, all three will be het; or if you're unlucky, none wil be het. Given enough babies, they will hold true to the stats in most cases.

 

[PaulSage]

Okay, you guys even have me second guessing myself! :main_laugh:

The father of the gecko in question is a Blizzard het for Albino (looks like a blizzard, but carries the albino gene). The mom is a double het for blizzard and albino (she looks normal, but carries both traits).

I whipped up a Punnet square for the breeding. The possible alleles that the male can pass on are in blue, the female's in pink. A "visual" blizzard, such as the one in question, is highlighted in yellow.

Now, this is where Paul gets a little confused. IF we weren't dealing with a double-recessive cross, I buy the 66% term. However, since it is theoretically possible for a visual blizzard to also be a visual albino from this pairing, we can eliminate one of the potential outcomes since the blizzard in question is not a "blazing" (the "aabb" one in the bottom corner). So, instead of having the 2/3 or 66%, we have 5/7 or 71%. Right?

I remember the 71% stat from a genetics class I had taken, but since I've never heard it mentioned in reptile genetics, I just go with the flow. lol I could very well be off my rocker though, it has been a rather spastic week...

 

[Grinning Geckos]

HAHAHA Paul....there you go complicating things by doing double recessive! I was just trying to get them to understand single recessive first.

Holy crap, now I'm really confused myself.

OH, I see a mistake in your square! Look at the bottom square, 3 over. When you correct that and focus on just the albino gene, the percentages are still the same - 1/4 chance of albino, 2/3 chance of het, 1/3 chance of normal.

 

[PaulSage]

OOPS. I'm off my rocker afterall. There's an error in the table - column 4 row 5. It should say aabb instead. I made the table in Word, and the dang "auto-correct" thing screwed up the capitalization. Now I'm going to have to dig through all my school crap and find out where the 71 comes in. Then, I'm just going to go sit in the corner and shut up.

I'm going to delete the table just so that I don't confuse anyone. lol

 

[gko reptiles]

Ok guys here we go again... Jeff isn't even in highschool yet. I tried to explain it in the simplest way possible without confusing anyone. I agree that the statistical output is NOT what you would nessecarily hatch out, BUT it does help to use a small group of animals that just happened to 'turn out' the way that they 'should' (if all of the genetics worked as they 'should') as an example. He did, however, know what a Punnett Square was, and last night when I PMed him, he understood my post fairly easily. He had a few more questions about it, and I answered them. All in all, he 'gets it', and since everyone is currently confusing everyone else at the moment, let's just all assume that we know it and not argue about the same thing over and over. We're all relatively smart adults, or young adults, here who all seem to know where the 66% comes from, just in different ways. We all get it, and now Jeff gets it, so lets not argue abut who's way is right! We're all getting the same answer!

 

[Grinning Geckos]

Except for Paul! :main_laugh: LOL....I had to.

 

[Jeff876533]

Ummmm....I actually do understand the genetics and all that was enough to confuse me....who knows what poor Jeff is thinking!! So...let me try to explain it in simple terms.

Het means they are carrying 1/2 of the genetic code needed for making a particular morph...in this case albino. No ifs, ands, or buts - the genetic material is there, but you can't see it.

I have to make a punnet square for this next part. We'll use "N" to represent the normal gene and "a" to represent the albino gene. One parent goes across the top, and one goes down the side. Remember - Het means they only carry 1/2 the code .... so they only get 1 a. Then you use it sorta like a multiplication chart...fill in the blanks going down and to the side. The four inside boxes represent your offspring. (Ignore the dots...I just used them for spacing)

.....l....N....l....a....l
----------------------

N...l...NN...l...Na...l
----------------------
a....l...Na...l...aa...l
----------------------

This reads as:

Of four babies, 1 will be totally normal (NN) and it will never be able to produce an ablino because there isn't the gene for the albino there.

Of four babies, 2 will be het for albino (Na) and they can make albino babies, but don't look like albinos thenselves.

Of four babies, 1 will be albino (aa).

(Please note...this is your statistical chances of hatching...not what actually will hatch)

That gives you 1 albino, 2 hets, and 1 normal. We're going to pretend like the albino doesn't exist now and just focus on the hets and the normal. That leaves you will 3 babies to worry about. The normal looks normal (of course)...but so do the hets. So how do you tell them apart? The problem is YOU CAN'T. All 3 babies look normal, but you know that statistically 2 of them carry the genetic material for albino.

SO

2 divided by 3 = 66%

What ALL of this boils down to is you have a 66% chance of that gecko carrying the gene for albino (meaning it can make albino babies)...but you ALSO have a 33% chance your gecko is completely normal and it will never make albino babies.

WHEW! I really hope that was easier for you to understand.

wow that just made me understand completely about het. thanks a ton! i ahve one last question thou, the het in the example punnett square is 100% het right? and also, what would happen if the leo was 66% het? would it work the same as it being 100% het?

 

[brandy101010]

if the 66% het actually turned out to be het, yes it would work the same. but remember 66% het means there is only a 66% chance of said animal being a het.