Letters from a Fascinated but Frustrated Scientist

by Andoriol

On Alicorns and their Rarity

To: Celestia, Luna, those assholes that don’t get what the word alicorn means, and to whomever else it may concern
The Nature of Alicorns from a Genetic Perspective

By Emeris Fillson

This paper was drafted in response to the numerous times ponies seem to not understand the meaning of and misuse the word alicorn.

As a preamble to the rest of this paper, I need to cover something rather important. Equestrian genetics appear to have six distinct layers of dominance which are as per follows:

• Primary Dominance (PD): One copy of the gene will override all others and will be expressed
• Secondary Dominance (SD): One copy of the gene will express itself over a pair of Partial Recessive or Full Recessive genes, but not over two Neutral genes.
• Neutral Dominance (ND): Two copies of the gene will override a single Secondary Dominant gene and it will be expressed over secondary recessive genes unless there is a pair of SR genes. When there is a single SD and two ND genes, or one ND and two SR genes, their dominance balances out, and the two groups of genetics are expressed equally.
• Secondary Recessive (SR): Two copies of the gene are required for it to be expressed at all, and these genes are normally only expressed in tangential ways, these genetics are rare and normally add traits such as a curve to a unicorns horn, or specific feather patterns in Pegasi. However, when there are no higher dominance genes, these genes may express themselves, leading to either considerable power, or considerable failure. The inbreeding of some Noble Herds has produced some of the most powerful ponies alive, but also some of the most deformed. The two are not always mutually exclusive.
• Primary Recessive (PR): These genes will only express themselves when in a trio. Even a pair of matched PR genes will not override a single SR gene. The only way for PR traits to express themselves properly is if the pony has a full set. Two identical PR genes will normally express themselves over a single other PR gene, but this is not always the case, and I believe epigenetics may be the cause. These genetics are particularly rare however, and much of the information on them is theoretical.
• Merger Genes (M): This is not a separate category in of itself, but an attached category. Genes that fall in this category will explicitly blend the expressed traits when paired with other genetics of equal dominance. 1 PD gene and 2 SD genes. 1 SD gene and 2 ND genes. 1 ND gene and 2 SR genes.

Additionally, the ‘tribe’ of a pony seems to be determined by three sets of genes. Which is a total of 9 chromosomes. One set for enabling the expression of traits of each of the three tribes.

As best as I can determine, the gene pool appears to have genes with the following dominance distributions: 3 PD genes, 2 SD genes, 2 ND genes, 2 SR genes, and 1 PR gene for each of these three triploid groups. The determining genetics for the expression of Earth pony traits may have one fewer PD gene and one more SR gene, the margin of error for this conclusion however is currently unacceptably high.

With this information in mind, as well as the triploid nature of pony genetics, the following may be addressed:

Alicorns.

Specifcally, the definition of an Alicorn.

According to my observations, there appear to be several kinds of entities which receive the designation, which I will attempt to classify and separate.

• Hybrids: These are the main group which come close to alicorns, and is the most populous. Hybrids are ponies which express traits of more than one tribe. More than a few ponies in Equestria do so ever since the more profound mixing of the tribes in recent times. Hybrids can be classified into the following groups:

o Imperfect Hybrids: These hybrids are a particular tribe, but express multiple traits from another tribe. Shining armor is an example of one of these kinds of pony, for despite being a unicorn (and a powerful one at that), he shows some of the disproportionate strength and stamina of an Earth Pony. These are the most widespread and easily found of the hybrids, and these are normally a unicorn or pegasus that expresses earth pony traits, but occasionally there is a unicorn that shows talent for what is normally pegasus exclusive magic, or a pegasus that shows a particular ‘artistry’ in their manipulation of clouds and lightning. These ponies only need a specific set of ND or SR genes in at least two of the three tribe genes. While uncommon, they are not exactly rare either, as these genetics are wide spread, and spreading more as the tribes intermingle.

o Perfect DiHybrids: These are considerably rarer, and are a full expression of the traits of two tribes. Prince Blueblood is an example of this kind of hybrid, having the disproportionate strength, greater size of an Earth pony, but also the horn and full magical power of a unicorn. These hybrids can only be achieved by certain combinations of SR or PR genes in two of the three tribe genetics, and as such, are noticeably rarer, normally only found in noble lineages due to careful breeding. While a Winged Unicorn or ‘Pegacorn’ may be called an alicorn, I contest such a title. They are a hybrid, but as they do not express earth pony genetics, I do not believe it is appropriate to call them by the alicorn title, a title of magic and power.

o Imperfect TriHybrids: These are ponies that fully express the traits of two tribes, but also some of the traits of a third tribe. These are the first ponies that can reasonably be called Alicorns. Princess Mi Amore Cadenza is the most famous of these currently alive. She fully expresses both Unicorn and Pegasus traits (though her wings are weak by pegasus standards) and she expresses some earth pony traits as well. These can only exist if a combination of SR and PR traits in all three tribe genetics are achieved. SR genetics only yield a partially expressed trait, whereas PR traits yield full expression. As they express the traits of all three tribes in some fashion or another, their power is actually inherently a degree of magnitude greater than those of other ponies, most likely due to a sympathetic resonance of some kind.

o Alicorns (Perfect TriHybrids): These ponies have full expression of the traits of all three tribes. To my knowledge, these are rare, but not unheard of. Such an expression requires a full suite of PR traits in all three of the tribe genes. Additionally, a full alicorn would be larger than the average pony, appearing more like the Princesses than the mean body type of Equestrians. A full alicorn would not be a being equivalent to the Princesses however, though they may be immortal unless killed, and their power two degrees of magnitude over that of an average pony.

• Divine Alicorns: There are currently only the two Princesses in this category. Beings of immense magical power, masters of celestial bodies, immortal and ancient, weilders of unique magical power. How such alicorns come into being is unknown to me, and I make no attempts at discovering such. It is not purely genetic, as they share the same tribe genetic markers as a Perfect Trihybrid would.
Divine Alicorns are separated from their non-divine counterparts by several factors, the exact nature of their mane, their cutie mark, and their size. While an Alicorn may have a flowing mane due to their raw power, it would lack the ethereal or mystical quality that those of the Princesses have. Additionally, the cutie mark of a divine alicorn directly correlates to their purview (I theorize that Princess Mi Amore Cadenza may, in fact, in time become a Divine Alicorn of Love, but this is unfounded theory on my part). And finally, Divine Alicorns are a full head taller than their non-divine counterparts.

While the dominance of the tribe genes seems to be counter-intuitive to their expression, a full suite of PR genes appears to block the expression of the other tribes genetics if the enabling genes are not PD genes.

Assuming an even distribution of genetics (this is false, there are a surprisingly small number of PR genes in the gene pool), the following is true:

There are 10 possible genes for each of the three triploid groups. Only one of those ten yields an Alicorn, and even then, only when all 9 of the genes are one of these particularly recessive genes. 1/10 ^ 9, or one out of every billion. Considering that by the rough estimates of several historians, Equestrian society has only seen 89 billion ponies in its entire existence, this would put Perfect TriHybrid numbers at a mere 89. This is again assuming equal distribution of genetics, which is not the case. It is likely that only a select few lineages actually carried the gene for millenia, and only with the considerable intermingling of the tribes has it become more widespread. According to the Princesses, there have only been 17 true Alicorns in the entirety of their multi-millennial reigns.

Aside:

During my initial two years in Equestria I was what would be classified as a Divine Alicorn due to my mane, cutie mark, size, and raw power. However, this was not a natural state, and these effects were burned from me along with the curse that caused the warpings of reality about me.

I retain the genetics of a Perfect Trihybrid, but due to the metaphysical excising of my pegasus nature, the genes have been suppressed almost to entirely. This is likely done through a combination of epigenetics and magic-particle interactions that I currently do not understand. However, the end result is the same. While I retain the genes of a Perfect Trihybrid, I am a Perfect DiHybrid, expressing the full natures of both Earth Ponies and Unicorns.

No. I am not going to stud for the sake of ‘spreading the alicorn genes about’. It wouldn’t even work due to my epigenetics essentially rendering the genes useless so stop sending me bucking letters and invites.

Best Wishes,

Emeris Fillson

Comments

[banjo2E]

I bucking love Emeris.

[archonix]

That end note.

[Andoriol]

1619534

Though if I may ask: What do you love about Emeris? For future reference and any other characters I may make

1619839
I think that's going to become Emeris' sort of signature really, a lot like Twilight's "Your Faithful Student" mess

AAHHHHHHH ARRGGHHLLEBLARGLE YOU FUCKING MOTHERFUCKERS

Best Wishes,
Emeris Fillson

[Lighting Ace]

Emeris, reports are half way to become the new subject of study in Equestria universities. I even see a book with the picture of him on the cover.

Something tells me that princess Luna is particulate found on this reports, after all she inspire him to write and document all of that and I bet she is eager to help him, explore more of Equestria Anatomy, history, genetic and even the mystery of magic.

Oh please make him and Luna a couple, I can see them together and this time I will win her heart the right way, and not because of the curse. Beside It may help with what is happening with Twilight when she confuse that with something he is planning.
Ah, and remember, he didn't see Luna that often because of the curse, but he admit that he like the night more than the day.

[banjo2E]

1620396

Just kind of Emeris in general? He's an excellent, fleshed-out character (in the other fic) with a nice writing style (in this one).

[TheGreatSako]

No. I am not going to stud for the sake of ‘spreading the alicorn genes about’. It wouldn’t even work due to my epigenetics essentially rendering the genes useless so stop sending me bucking letters and invites.

Aww, that's no fun.

[SpinelStride]

Hmmm... We did see Twilight's mane start to show some twinkles when she was carrying the full load of alicorn magic. So it might be that 'divine' alicorns are simply alicorns who by some means have accessed even more magical power than genetics alone can account for.

[Alondro]

Oh goody goody, developmental genetics. One of my fields of research!

The ponies being triploid is a very strange situation. I would wager that for stable cell division their cells must undergo trinary fission, with a genetic replication machinery that produces 2 new genetic strands instead of 1. This would work if their genetic material existed as a triple helix composed of bases and a structural backbone of a somewhat different chemical composition from our DNA and the phosphate backbone of each single strand, hence why I do not call the pony genetic material 'DNA'.

Primary Dominance (PD): most likely involves normal genes producing a product that serves a direct, basic physiological/developmental funcion such that only a single functional copy produces all the product required. Most single subunit enzymes, peptide hormones, structural proteins and many types of receptors fall into this class. Also such things as tumor suppressor genes and transcriptional and translational machinery will suffice with a single functional copy. May include a mechanism such as containing a microRNA to suppress all other forms of the gene in the instance that there is active suppression versus passive loss in the second copy from deletion or premature stop codons and missense mutations.

Secondary Dominance (SD): Same as above but without any suppression of the other polymorphisms. The f

Neutral Dominance (ND): This seems to indicate some form of negative feedback cascade is in action, wherein certain forms of the gene suppress others selectively. Some polymorphisms may contain inhibitory regions which are able to block action of certain other forms of the product. Or, microRNA may be present in the coding which targets secondardy dominant sequences for inhibition.

Secondary recessives (SR): This is a bizarre case, which I can only assume functions via a mechanism not found in terrestrial organisms. I could hypothesize that each copy produced a short product, either a microRNA or a small peptide which then serves to activate a secondary coding region. But this assumes that there are actually two forms of the secondary recessive polymorphism, each with signal region and binding region complementary to the other. It is the only mechanism I can think of which would activate in such a specific manner.

Primary recessives (PR): Some of these seem to be the more classical recessives, mutants whose effects are silenced by the presence of even one normal gene. Most likely they are deletion, missense, or one of the other loss-of-function mutants. If there is a functional product produced only by the tandem expression of the 3 copies, I cannot postulate a genetic mechanism for it outside of a system that is so complicated I won't even bother describing it as I cannot see how such a thing could ever develop naturally, or why a creator would bother with it as it would be at very high risk of elimination from the population through natural mutation rates (that, and it took half a page to flesh out, and even then didn't make much sense, since again it required 3 different forms of PR gene to receive 3 different signals and produce 3 different products. If the three copies produce the same thing, and all possess the same promoter and enchancer sequences, then there is absolutely no way this system can exist.).

Merger genes: These simply seem to be polymorphisms expressed in the same way many such gene variants are expressed on Earth. Their products most likely serve the same central function, but with subtle variations... such as different pore opening times between polymorphisms of sodium channel subunits or substrate binding specificity and reaction rates of enzyme polymorphisms.

Summary for this chapter: I'm finding this genetic system rather awkward. If I am reading this correctly, then each gene has polymorphisms of each dominance class with multiple forms of exceedingly intricate internal feedback mechanisms and multi-tiered activation pathways. It's a system I cannot see being stable in the long term over geologic timescales. Mutation would tend to result in the loss of the pathways involving two- and three-gene requirements.