Article 48: Genetics

The Milky Way galaxy is a fairly diverse place. The Golden Alliance catalogs at least three hundred individual races within twelve large racial groups, and despite the bickering political factions that have a hand in most interplanetary dealings, the truth of the matter is that most people get along with each other pretty well. Though there's always going to be the occasional xenophobe or culture that disapproves of disparate racial pairings, if you really fall in love with someone of another race, there will always be a way for that relationship to be the start of a family. With that in mind, it's easy to wonder why all of the galactic races haven't interbred over thousands of years of cross-cultural meetups to create more homogeneous mixes of galactic races. The answers to why exactly that is have to do with still-unknown galactic mysteries, but geneticists and other biologists have discovered some key facts that help point towards the answers while giving us insight into exactly how cross-species reproduction functions.

The first thing to understand is that no union is entirely impossible. Given the nature of magical spells and multiple advances in genetic research, any two people can theoretically have a child, even if it means both have to magically have their races or sexes changed or they must undergo various fertility treatments. Regardless of that, however, many races throughout the galaxy are inherently genetically compatible to some degree, and that compatibility is represented by the average percentage chance that any given male and female couple of that racial pairing will be able to produce offspring without assistance. For example, if two parents of different races have a genetic compatibility rating of 50%, there is a 50% chance that the pair will be able to conceive at all. Were each partner to pair with another member of that same race, there would still be a 50% chance of that new union being able to produce an offspring. Of races that sexually reproduce, all races within a specific racial group have at minimum a 25% compatibility rate with each other, often higher. Some racial pairings have substantially higher compatibility chances. High Elves, Wood Elves, and Dark Elves, even though Dark Elves are part of another racial group entirely, all share a near-100% compatibility rate. Similarly, specific subraces of both martial and domestic Demi-Humans tend to have high compatibility ratings with races that they resemble, such as Fox-based Demi-Humans and the Kitsunes that inspired their original design. Humans and their various subraces are unique in that they hold the highest amount of total compatibility with other races, with no pairing having less than a 50% compatibility rating. Speculation for why humanoid races that allegedly each developed through millions of years of evolution somehow are able to breed includes theories of panspermia, convergent evolution, and genetic tampering by ancient alien races.

Now that we understand the potential of races to mix, the next question that people tend to ask is why we see so few people of mixed race. Once again, the answer lies in genetics, but things can tend to get muddled and there are always exceptions that arise every time a rule is established. Typically, when a child is born to parents of different races, the children are much more likely to inherit the physical traits of the mother, with a 50% chance of this happening. In another 25% of cases, the child takes the father's racial appearance, and in the remaining 25% of cases, the child is born with what you would most typically associate with a mixed-race appearance, with elements from both parents' races mixing together. In all three cases, the child has what is called an "inherent bloodline", where they may learn and improve on the racial abilities of their primary race like anyone else, but may also do the same for their inherited other race, even if they do not outwardly appear to be that race. But here's where things get choppy.

Because of the weirdness inherent in genetics, even mixed-race beings will never directly contribute more than a single race's genetics to any given offspring. There is a small chance during one of these unions that a child may inherit the bloodline abilities of a tertiary race, but they will not naturally be able to access that race's traits through normal means. The result of this is that You never see quarter-dilutions of different races, or someone whose genetics suggest a mix of three or more races, and no matter how many mixed genetics are present at the time of conception, the children are still predominantly a single race with perhaps the potential to gain abilities inherent to another race. So while love can conquer any barrier, the diversity of the galaxy is going to remain strong for many, many generations to come.

Of course, there are always exceptions to these rules, and oddities that have spawned as a result of them. After the rebelling Divine were expelled to the edge of the galaxy, the Protectorate made an effort to find and sterilize all children produced through the union of Divine and non-Divine races. Those that were missed were ones with an undetectable bloodline that has since been reawakened to create a subspecies of humanity called "Celestials". Succubi will always produce children that invariably become Succubi upon reaching sexual maturity. Shapeshifters can create children of other shapeshifter races, including ones that have previously been undiscovered. And frequent use of race-changing magic can result in genes being passed down that seem entirely alien to both parents. The field of mahougenetics is wide and still has a lot of territory left to be uncovered.