Do I want to learn about genetics? Yes. Is it very intimidating and scary? Yes.

[black_cat]

This is getting really interesting (and way over my head... but I'm learning a lot!)! And once again, sorry we're stealing your thread @black_cat ...

Again....stealing is great!! Ask all the questions!! Learn all the things!!! It's what BYC is for!!

 

[MysteryChicken]

I fail to understand why AT first since you stated the heritage and it isn't pure for birchen in genotype (hidden or not seen genes) as you asked in the question and was answered already... regardless of phenotype which is what's being referred to as the faux birchen or whatever that word someone called it was.. But on second thought, I do love to see updated photos and good mysteries.. I just don't wanna run of course focused on a single bird is all.

I don't care what his phenotype (aka LOOKS) are... we are discussing genetics and possible outcomes.. simply put black cross silver colombian (Light Brahma) does not equal birchen. It equals black with silver leakage. Although genetics are complicated they are also kinda black and white. I do love to see how different chick phenotypes can still end up looking *basically* the same as each other at maturity.

Having worked with several breeds this link has TOO much good information to reference to not be included.. Sometimes when you're working with a specific breed and having trouble finding GOOD information.. I find it helpful to look at what's taking place in the same variety but other breeds perhaps that may have been more well studied or published..
http://frenchmaransclubaustralia.yolasite.com/notes-on-breeding.php

And this one too.. CHART HEAVY..
https://sites.google.com/site/belgianbantamclub/breedingbelgianbantams

A genetics mini series that looks pretty good.. I see they're also touting FF on their site which I tried long term plus tons of research and my results DON'T support the HYPE... so please ALWAYS use your own best judgement! (after reading the FF page, it wasn't overboard and was fairly balanced in suggestions)..
https://scratchcradle.wordpress.com/genetics-mini-series/

So much information my bookmarks are starting to need bookmarks!

I didn't say black cross silver colombian makes Birchen. I was pointing out what usually happens when you mix Birchen with another colored bird.

 

[EmmaRainboe]

Is there a way to like send in a feather or something and do some kind of test and can figure out a birds full genotype?

 

[EmmaRainboe]

You asked where crossing over was.

What does "crossing over" mean?

 

[EmmaRainboe]

Yes, he isn’t birchen. He is actually black with leakage. Even though he looks like birchen. Some people color “psuedo-birchen.”

What causes the lacing on his chest? Would it be from the black cochin or light brahma? Is that something possible to know?

 

[Quatie]

Crossing over occurs when gametes are formed. You have pairs of chromosomes swap DNA with each other. So you may have a dominant gene on one pair and a recessive on the other pair. They can be swapped from one pair to another.

This may give you a better visual

http://www.phschool.com/science/biology_place/labbench/lab3/crossovr.html

 

[EmmaRainboe]

Crossing over occurs when gametes are formed. You have pairs of chromosomes swap DNA with each other. So you may have a dominant gene on one pair and a recessive on the other pair. They can be swapped from one pair to another.

This may give you a better visual

http://www.phschool.com/science/biology_place/labbench/lab3/crossovr.html

Ohhhhh yeah I remember this now, thank you!

 

[Amer]

What causes the lacing on his chest? Would it be from the black cochin or light brahma? Is that something possible to know?

The Brahma.

 

[EmmaRainboe]

So O/O is a blue layer, is O/o a blue layer? What would a brown/tan/white/cream layer be, would they all be on different genes, because for like an olive egger you need blue and brown? Or would o/o be white? Because blue and white are both actual shell, while brown and everything else is the coating ontop?

 

[ChocolateMouse]

So O/O is a blue layer, is O/o a blue layer? What would a brown/tan/white/cream layer be, would they all be on different genes, because for like an olive egger you need blue and brown? Or would o/o be white? Because blue and white are both actual shell, while brown and everything else is the coating ontop?

Brown and white are a spectrum, including redness and thickness of bloom, etc. Different shades of brown are a complex series of genes that range from stark white to marans deep.

The blue is its own gene and is irrelevant of any color in the bloom. It's a gene that puts oocyanin in the calcium of the eggshell structure itself, as opposed to a coating on the inside. Blue eggs are blue on the inside and brown eggs are white inside. Depth of color is partially determined by more complex genes, but the presence of blue in general is its own color determined by a single simple dominant gene.

And you're correct, you need a blue base with a dark brown coating for an olive egg and even many blue egg layers actually have a small amount of brown bloom to darken and enhance the color. The best blue eggs are often actually more cream if you took away the blue coloration.