Peafowl Genetics for Dummies (in other words us)

[Dany12]

About the black shoulder.
Why only the male change of color - it is a change related to sex?
This program is probably on the sex chromosome of the peahen!

 

[AugeredIn]

Could someone please change the name of this thread from "Peafowl Genetics for Dummies" to "Peafowl Genetics for People Who Know What They Are Talking About"? The current title qualifies as false advertising.

Well, I would but I would make the following points:

1. This thread could easily become a sticky as there is some of the most straight forward explanations of genetics that have ever been posted in this forum. The problem is that no matter how easy some people think this issue is not everyone will understand. I say this with no disrespect to anyone here but when a person has a background in a field it is easy to them so it seems like it should be easy to everyone when it is not. I still would strive for an easier visual based language that we can all understand.

A long time ago, I spent a lot of time in school studying aeronautical engineering. I learned all about the mechanics of wing cross sections and surface deflections and what makes a plane fly. I was also privileged to fly a high performance aircraft with one of the greatest pilots ever. At the time I had already spent a lot of time in other aircraft so I knew how to fly. You know what he told me when I tried to engage him in an aeronautics instruction? He said, Phil today none of that means anything. Keep it simple. Push the stick forward to go down, pull the stick back to go up. Push it left or right to turn that direction. Don't let the airspeed drop below 125 unless you want to land or ruin our day.

2. We are on page 14 of this thread and have no consensus on what silver pied is or is not.

 

[frenchblackcopper]

India Blue x Bronze w/e =?
Midnight B/S X India Blue w/e +?

For me to know and understand this, I need a starting point to imput known visual and non visual genetics in both the parents column with all the possibilities and percentages of the possible offspring to then be computed-whatever in another column. Like a spreadsheet or slide ruler. I'm like you AugeredIN. certain skill sets every individual excels at. Genetics has changed so much from what we were taught in high school foir me,theres no catching up. Heck,learning how to use a home computer was bad enough,,I used to laugh at classmates that took typing class. Now I hunt and pick my way on a keyboard daily.

 

[Arbor]

IB x Bronze w/e (single copy) = all offspring split to bronze, 50% of which are single copy w/e

IB x Bronze W/E (double copy) = all offspring split to bronze and carry one copy w/e

Midnight BS x IB w/e (single copy) = all offspring split to Midnight and BS, 50% of which are single copy w/e

Midnight BS x IB W/E (double copy) = all offspring split to Midnight and BS and all carry single copy w/e

 

[Rosa moschata]

India Blue x Bronze w/e =?
Midnight B/S X India Blue w/e +?

For me to know and understand this, I need a starting point to imput known visual and non visual genetics in both the parents column with all the possibilities and percentages of the possible offspring to then be computed-whatever in another column. Like a spreadsheet or slide ruler. I'm like you AugeredIN. certain skill sets every individual excels at. Genetics has changed so much from what we were taught in high school foir me,theres no catching up. Heck,learning how to use a home computer was bad enough,,I used to laugh at classmates that took typing class. Now I hunt and pick my way on a keyboard daily.

A Beginner's Guide To Punnett Squares

 

[frenchblackcopper]

Arbor,,I used those birds as an example,,but for me to know and understand the "what will I get if?" I need a comprehensive chart,something like this

Phenotype: Grandparents of Sire Peacock- Sire-100% India Blue
Peahen sire-100% Black Shoulder Silver Pied

Phenotype: Grandparents of Peahen mom- Sire-India Blue split to b/s
Peahen sire-Bronze b/s,w/e

Phenotype: Peacock sire-India Blue Black Shoulder-white flights-few w/eyes in train

Phenotype: Peahen mom-India Blue Black Shoulder

Now if other squares can be used to add any additional Genotypes we may know exists in the grandparents and the parents,completing as much geneotyping in these 6 birds (4 grandparents-2 parents) we then hit the button "submit" and out would come the probabilities of what the mated parent birds could possibly hatch with percentages.

 

[frenchblackcopper]

Rosa,is it possible to make a Punnets square with 6 known parents or more? I watched several of the youtube links you added but when they got to some of the letters not being used such as in the dihybridized flowers genetics then I really got lost.I get confused on some of his examples where carrying down and across comes in,using the first letter sometimes of the two for a specific parent.

 

[Arbor]

I'll send you an email in the next week or two, it'll put all your q's to rest

 

[Rosa moschata]

Rosa,is it possible to make a Punnets square with 6 known parents or more? I watched several of the youtube links you added but when they got to some of the letters not being used such as in the dihybridized flowers genetics then I really got lost.I get confused on some of his examples where carrying down and across comes in,using the first letter sometimes of the two for a specific parent.

Draw along with me if it helps you to "see" what I'm saying.....

You make one punnett square for each pairing. If you have 6 parents, you make one square per couple. The square is a tool for figuring out what the eggs or sperm will carry with respect to the traits concerned (each trait has two versions -- "normal" and mutated, such as IB and Bronze). The number of boxes in each square will depend on how many traits you're inputting -- 2 (referring to 2 of each chromosome, thus 2 possibilities to pass down) to the power of the number of traits is the number of boxes across, and the same number down, for each parent. So if you're doing just IB split Bronze X IB split Bronze, that's 2 to the power of 1, which equals 2 across by 2 down, giving 4 total boxes (or 1/4 probability per box). If you're doing IB split Bronze and Blackshoulder X IB split Bronze and Blackshoulder, that's 2 to the power of 2 (which is 2 squared, which equals 4) on each side, giving 16 total boxes in the square (or 1/16 probability per box). Remember each "box" represents an offspring probability of the parents used in the Punnett Square.

So give me an example of one of your pairs, in the following form:

Male X Female

And be precise about what they are. Remember how I said "split" is properly used? So first type "what you see" expressed, then "split", then what you know they carry. As an example:

IB Single Factor White Eye split to Bronze and Midnight and Blackshoulder X IB Blackshoulder split to Bronze and Midnight

That one will be quite a doozy of a Punnett Square, being more efficient on a genetic calculator. Remember how I said to determine how many boxes across and how many down in your Punnett Square? It's 2 to the power of the number of traits. So we have White Eye, Bronze, Midnight and Blackshoulder. That's 4 traits. 2 to the power of 4 = 16 boxes across, and 16 boxes down, giving a total of 256 total boxes in that Punnett Square.

 

[Rosa moschata]

The Punnett Square is a visual way of figuring out what you get. When you have a bunch of traits, however, it may be easier to just do the math to figure out the odds of a particular offspring. Remember about determining the probability of multiple things happening together? You multiply the probabilities of each occurring separately. So going back to that make-believe pair:

IB Single Factor White Eye split to Bronze and Midnight and Blackshoulder X IB Blackshoulder split to Bronze and Midnight

Each trait for which the parent has two versions gives a 1/2 possibility of passing down either. Being Single Factor White Eye means the male has a 1/2 chance of passing down White Eye, and a 1/2 chance of passing down the "normal" version of that gene. Being split to Bronze means the male has a 1/2 chance of passing down Bronze, and a 1/2 chance of passing down the "normal" version of that gene. So to figure out the odds of passing down White Eye and Bronze TOGETHER, that's 1/2 X 1/2 = 1/4. But that's just Dad. Mom doesn't have White Eye, so she passes down "normal" only on that trait. She does have one copy of Bronze, however, so there's a 1/2 chance of passing that down. So if you want to know the odds of getting a pea that is Bronze Single Factor White Eye (and you don't care whether it is/isn't/carries anything else), that'd be 1/4 (Dad) X 1/2 (Mom) = 1/8.

Let's say you want to see the odds of getting a Midnight Bronze Blackshoulder (whether or not it has White Eye is unimportant). Since Mom already is Blackshoulder, she can pass down only Blackshoulder (not barred wing), so that helps.

So that's 1/2 X 1/2 X 1/2 = 1/8 for Dad, and 1 X 1/2 X 1/2 = 1/4 for Mom.

1/8 X 1/4 = 1/32 chance of a Bronze Midnight Blackshoulder offspring. Note that half of these will also have 1 copy of White Eye from Dad. See how I got that?