Medusa and Futakuchi-chan - Vol. 3 Ch. 61.5 - [Extra] Concerning the Species in this World

[MangaDex]

 

[looc64]

Ah, I was thinking this sort of system makes a lot more sense than the setting you usually see where the result of two species breeding is a hybrid.

Cuz usually in setting where everyone's a yokai or a monster or an animal or something there's a. only 1-2 families of each species when the series starts, b. none or very few hybrids, and c. marriage seems to work like it does in real life.

If the result of two different species having a kid is a hybrid then at least one of those things shouldn't be true.

If b and c are true, then there should be multiple families for each species such that each generation of that species can easily partner up with another member of that species.

If a and c are true, then there should be tons of hybrids because most character wouldn't be able to find partners of the same species.

And finally if a and b are true, there should be some sort of system connecting distant members of the same species and forcing them to marry each other.

 

[flannan]

Ah, I was thinking this sort of system makes a lot more sense than the setting you usually see where the result of two species breeding is a hybrid.

Cuz usually in setting where everyone's a yokai or a monster or an animal or something there's a. only 1-2 families of each species when the series starts, b. none or very few hybrids, and c. marriage seems to work like it does in real life.

If the result of two different species having a kid is a hybrid then at least one of those things shouldn't be true.

If b and c are true, then there should be multiple families for each species such that each generation of that species can easily partner up with another member of that species.

If a and c are true, then there should be tons of hybrids because most character wouldn't be able to find partners of the same species.

And finally if a and b are true, there should be some sort of system connecting distant members of the same species and forcing them to marry each other.

In Centaur's Worries, B and C are true. This is made possible because the whole population of Earth is mostly 5 major "human" species (non-humans like Antarticans and Amphibians can't interbreed with humans). Also, hybrids tend to be unhealthy, which is why we don't see many of them (it's mostly the class rep's family, where father is a cat-man, and mother was an angel).

Still, most of these settings make my knowledge of genetics cry in a corner. It's like there is a single gene responsible for determining species, and all the other information about how to grow up as a medusa or an air elemental exist in every monstergirl's genome.
If species was always inherited from mother, things would be simpler - we could say it does not depend on main DNA, but on everything else the child gets from the mother, such as mitochondrial DNA or something.