Ball Python Genetics simplified

Ok, so basically instead of haveing different genes that are the same allele, it is actually different alleles of the same gene, and each allele has its own place on the chromosome called a locus.

A little bit jumbled from how i see people talk about it, but it wouldnt be the first hobby to use genetics all wonkey (looking at you WD community and their missuse of the fillial system).

This makes sense. The pieces are all there, just the order wasnt correct that i was using.

1 Like

No… “morph” = random name that someone decided to call a mutation to try and pretend their animal is completely different from others already out there, some times it is legitimate, sometimes it is not.

“Allele” = is a very specifically defined unique genetic change.

As a perfect example; There is not genetic difference between Yellowbelly and Orangebelly. They are two different “morphs” that are actually the exact same thing. However, there are actually two genetically distinct mutations that are called Yellowbelly. Those are alleles


Locus is the location on the chromosome. Its like an address. The gene is the actual thing that sits there in that location. Say a building. Even if the parts are different that make up the gene, it is still the same gene as it sits in that specific spot. Still the same building, no matter what color you paint it, new windows you put in it, or sign you put out front (which the sign i guess could also be the morph name for the purposes of this bad analogy)


Yeah, i think i got it now, i thought it went gene - allele - locus and that it was the gene that changed, but its actually allele - gene - locus, and the allele changes, but they are all the same gene sitting at the same locus.

Im glad i made this post, i thought i had a good idea of how this all worked and its been great having other people more knowledgeable to help correct my misperceptions :slight_smile: once i have time ill have to update the slides on the OP so others dont see the slides and skip all the great info everyones posted.


Now this is interesting. Can you expand on this or give a link to read up? (About the 2 yellowbelly mutations)

1 Like

Check out Hannah’s comments on it on the Ball Python Genetics Project


Here is the blurb from the last email that came out from BPGP

Here are more details about our findings on the Yellowbelly Complex:

  1. We have found that there are actually two different mutations for Yellowbelly. The mutations are allelic and produce the same or very similar color patterns. Some Yellowbelly animals have one mutation. Other Yellowbelly animals have the other mutation. Ivory animals have two copies of one mutation, two copies of the other mutation, or one copy of each mutation. The similarity in color pattern between the mutations likely explains why breeders didn’t realize that there were two mutations.

  2. One of the mutations for Yellowbelly is much more common than the other mutation. We initially thought that the rare mutation might represent Orangebelly. However, we have found that Orangebelly is the same as the more common version of Yellowbelly.

  3. Mis-identification among morphs in the Yellowbelly Complex is somewhat common. For example, animals described as “Super Stripe” are sometimes “Super Specter” or vice versa. Other examples of mix-ups include “Highway” vs. “Freeway”, “Puma” vs. “Super Spark”, and “Puma” vs. “Super Stripe”. Mix-ups tend to be more common in animals with additional genes, which is not surprising.

  4. Our understanding is that Yellowbelly morph is sometimes difficult to identify. Therefore, we wondered, “What fraction of animals described as Yellowbelly are actually Yellowbelly?”. The answer: Most, but not all. We have found that approximately 4 out of 5 animals described as Yellowbelly are actually Yellowbelly. The remaining 1 out of 5 animals is not Yellowbelly. Mis-identification tends to be more common in animals with additional genes.


I still have to send them up one of my scaleless sheds for the project, thanks for reminding me this project exists!