Pony Genetics (An Investigation)

Shakespearicles recently did a blog post called Pony Genetics. I posted the gene chart I created around 4 years ago to use in my brainstorming there, but the post got me thinking and I decided to revisit the subject. As a result I came up with a new genetics chart/headcanon to use going forward and figured I'd share. (This chart does not include Zebra or Bat Ponies, and assumes that males cannot be Alicorns.)

I start with the following baseline rules:

1.) A pony's physical form (Earth Pony, Unicorn, or Pegasus) is designated by a 3-part gene sequence which I'll show using E's, U's, and P's.
a.) A female's gene tag includes a prefix "mini-marker" that designates their sub-specie (a, e, u, p for Alicorn, Earth Pony, Unicorn, and Pegasus)
b.) A male's sub-specie doesn't matter in inheritance and thus I denote males with a "-" prefix.

2.) The marker that has the greatest presence determines the sub-specie (EEE, EEU, or EEP would be Earth Pony for example).

3.) In the case of a tie (EUP), the child takes on the mother's race - in this situation, the child is *always* female.
a.) An EUP gene pony cannot be male as they inherit their mother's template, including gender.
b.) EUP ponies are "alicorn potential" - no pony without this gene set can ascend.

4.) Each parent only donates one random gene marker (ignoring mother's mini-marker) to the child's gene set. The final marker has equal chance of being E, U, or P - I attribute this random aspect to the magic that infuses the entire world and innate magical nature of the ponies.

To sum up, a baby receives their physical form from following places: One E, U, or P from Mother, one of these from father, and one random one from the world's magic. Additionally, a tie will receive sub-specie from mother and be female.

Here's a chart of possible combinations based on this:

And here are the percentage chance of type of offspring and gender from any particular male/female combo, not adjusting for a specific gene-set for the mother and father:

I plugged Mr. and Mrs. Cake into this system and found that they could have unicorn and pegasi children if they had following gene-sets:

1.) Mrs. Cake: eEEU, Mr. Cake: -EEP
-> Earth Pony: 77.78%
-> Unicorn: 11.11%
-> Pegasus: 11.11%

2.) Mrs. Cake: eEEP, Mr. Cake: -EEU
-> Earth Pony: 77.78%
-> Unicorn: 11.11%
-> Pegasus: 11.11%

3.) Mrs. Cake: eEUP, Mr. Cake: -EEE
-> Earth Pony: 77.78%
-> Unicorn: 11.11%
-> Pegasus: 11.11%

3.) Mrs. Cake: eEUP, Mr. Cake: -EEU
-> Earth Pony: 62.96%
-> Unicorn: 25.93%
-> Pegasus: 11.11%

3.) Mrs. Cake: eEUP, Mr. Cake: -EEP
-> Earth Pony: 62.96%
-> Unicorn: 11.11%
-> Pegasus: 25.93%

Any other combination resulted in no possibility of either unicorn, pegasus, or both being born.

For Twilight's and Cadance's ascensions, in this system they would have had to have been EUP gene ponies (uEUP for Twilight and pEUP for Cadance). Celestia would alter the mini-gene marker to an alicorn tag (call it a mutated, combined eup into a single marker) and the magical nature of ponies would allow the physical transformation of the body even late in life. This would then allow proper utilization of the various magic types - which brings me to...

Genetics of Magic in Ponies:

All of the above was simply concerning physical nature of the pony. Magic genetics is its own category in my setup. Here's a chart that may be fairly familiar to many:

For this part, it's a simple half/half inheritance from the parents. My take is that every pony has some level of magic potential for the three types of magic (Earth, Pegasus, Unicorn - I used the E, U, P symbols again...hope it doesn't confuse.)

Each pony has a six-marker set made up of two markers each for each type of magic. One each of these two comes from each parent and are either a strong marker (E, U, or P) or a weak marker (e, u, or p). Two strong markers (EE, UU, or PP) in a category denotes a high potential capability/capacity in that type of magic (assuming you can access it), two weak markers (ee, uu, or pp) denote a low potential, and one strong-one weak (Ee, Uu, or Pp) denotes an average potential.

You can thus end up with a unicorn that has a weak potential in unicorn magic, but strong potential in earth magic...which likely they would never be able to make use of, but could pass on to an Earth Pony child if they had one. Ponies with the physical gene marker of a sub-specie may have accidental or random access to magic not ordinary to their own.

* For example, if Pinkie Pie had physical genotype eEEU and magical genotype EeUUpp, she might randomly (or not so randomly) be able to mimic things that normally only a Unicorn would be able to do. (Pinkie Sense and other Pinkie-ness?)

* Or, if Fluttershy had physical genotype pEUP and magical genotype EEuuPp, she might be able to make a connection to the natural world and animals which is more common in Earth Ponies.

For alicorns, while any EUP physical genotype can be considered "alicorn potential," I take the stance that, for ascendance to be possible, the pony must have at least an average potential in all three types of magic and a strong potential in at least one (most likely the one fitting their original race). Cadance may have been pEUP-EeUUPP before the change and Twilight may have been uEUP-EeUUPp for example.

I may play more with all of this in the future, but that's where I'm sitting at the moment. Enjoy!

Comments

[Odd_Sarge]

This is really awesome. I'm gonna take a bit to digest this.

[Wodahseht]

Thanks to discussion on Discord, I've worked out some additional clarifications and details which will be added soon. In the meantime, please feel free to post questions/comments as I use them to further develop the idea.

[The Boisterous Brony]

intriguing... and useful!!