Understanding Genetics

[OatmealPotato]

I have a specific question and a more general question.

1). I've watched YouTube videos on genetics where they use the Punnet Square to show examples, usually of breeding a Normal with and Albino (something simple). I understand what they means by the offspring being Normal HET for Albino. What I'm a bit lost on is when they say things like 1/4 Normal, 1/2 Normal HET for Albino, and 1/4 Albino, when speaking of breeding 2 Normal HET for albino together. My question is: When they refer to 4 offspring, is that the literal number of offspring that will be produced when breeding 2 geckos? Can someone better explain this to me?

2). Can someone point me towards good resources, videos or articles, that can explain more about breeding and genetics?

Thanks in advance.

 

[stager]

No they mean one quarter so if you had 12 babies statistically 3 would have those genetics

 

[acpart]

For more information about leopard gecko genetics, check out:
leopardgeckowiki.com
reptilecalculator.com
Fun with Hets: Leopard Geckos Teach Genetics 101 | Gecko Time

Aliza

 

[tb144050]

Yep...those are just probabilities.. Lets say that "het allbino parent =Aa." so two "het albino parents = Aa x Aa". With each parent, there is a 50% cance of passing down the A (not albino) or the a (albino) gene.

So after doing the square method you see: 50% chance a hatchling got the A from parent 1....then a 50% chance the hatchling got A from parent 2. So about 25% of the hatchlings get the A gene from both parents.

Same with the "a" gene...half and half of those = about 25%.

The other 2 possibilities end up with an A and an "a" (from mom/dad or dad/mom), so 2 out of 4 possibilities will equal anout 50% being "het albino".

The only confirm-able hatchling will be the albinos. All the other hatchlings might actually be labeled "66% possible het albino,"........because if it isnt albino, that leaves a 2/3 chance it is "het albino" and a 1/3 chance it's "not het albino." The problem is you cant determine visually if it is "het a" or "not het a"..... :0

 

[OatmealPotato]

Thanks, guys. I understand that part now. I've been trying to read some things online, but I'm still not grasping it all. For example, I used the calculator to see the results of breeding a Patternless Mack Snow x Normal, but I don't understand how they got the results.

 

[tb144050]

In my last post, I think I only talked about the genetics of "albino" and how the hatchlings may receive different gene combinations from the parents. "Albino" is a double-recessive trait to be "active-ly" albino.

Thanks, guys. I understand that part now. I've been trying to read some things online, but I'm still not grasping it all. For example, I used the calculator to see the results of breeding a Patternless Mack Snow x Normal, but I don't understand how they got the results.

In your last post, you are talking about a Murphy Patternless Mack Snow?
1) Murphy Patternless is a "double-recessive" trait (like "albino").
2) Mack Snow is a 1dominant&1recessive trait (because 2dominants = "super snow")

Sooooo........when you mate a Mack Snow Patternless (Mm pp) to a "normal":

1) ALL the hatchlings receive a recessive "p" from the MSP...so they are ALL "het patternless."

2) About HALF of the hatchlings will receive "M" from the MSP..and the others will receive "m". So about HALF will be "Mack Snow"..and the others will be "normal" (not mack snow).


On a genetics calculator, the results are displayed as:

----------

	Percent	Morph
	1/2	Mack Snow HET Murphy Patternless
	1/2	"normal" (aka "wild type") HET Murphy Patternless

^^^source: Leopard Gecko Genetics Calculator

---------------------------------------

When thinking about genetics, take it ONE GENE AT A TIME:
-Ask yourself, how will the "albino" gene be passed down: "double-recessive required=active"
-Ask yourself, how will the "Mack Snow gene be passed: "1dominant=Mack snow"
-Ask yourself, basically, what is required of the type of gene. Then compare with the genes that the other parent has to offer. Then calculate the probabilities of "gene matches" and whether it will be "active" "het" or "normal" (based on the requirements of "recessive", "dominant", or other gene types.)

 

[tb144050]

Guide to Leopard Gecko Morphs an

This is the first page I studied when I wanted to learn about genetics. It will teach you about recessive vs dominant vs etc etc. Then, lower on the page, it will tell you what type of gene each morph is (such as "albino = recessive x 2"). After that, let the calculators do the work for you, as it gets CONFUSING when you factor in 2 or more genes or gene types.

For example, you could spend a whole day trying to determine the genetic outcomes/probabilites of "Mack Raptor x Mack het Eclipse het Tremper".......or you can plug it into the calculator, and get:

------------------
Genetic Outcomes

	Percent	Morph
	1/16	Eclipse HET Tremper Albino
	1/8	Mack Snow Albino (Tremper) HET Eclipse
	1/8	Mack Snow Eclipse HET Tremper Albino
	1/8	Mack Snow HET Tremper Albino, Eclipse
	1/8	Mack Snow RAPTOR
	1/16	RAPTOR
	1/16	Super RAPTOR
	1/16	Super Snow Albino (Tremper) HET Eclipse
	1/16	Super Snow HET Tremper Albino, Eclipse
	1/16	Total Eclipse HET Tremper Albino
	1/16	Tremper Albino HET Eclipse
	1/16	Wild Type HET Tremper Albino, Eclipse

-----

 

[EasiGregory]

I know some of this stuff seems super confusing at first but once you read it about ten times it starts sinking in :main_yes:. I'm a person that needs it repeated to me over and over to fully understand things so I've gone through and read multiple articles and post multiple times to finally get a basic grasp of things.

This site helped me a lot as well http://www.newenglandreptile.com/genetics_simple_recessive.html

Gregory