“Race in My Little Pony”, 2018-06-04 (; backlinks; similar):
In MLP:FiM, the 3 pony races sometimes bear offspring of other pony races; I review 4 complicated Mendelian models attempting to explain this, and note that a standard polygenic liability-threshold model can fit it parsimoniously.
(For background on My Little Pony: Friendship is Magic, see my review of My Little Pony.)
Another fictional universe with genetic mechanisms is My Little Pony: Friendship Is Magic, where there are 3 pony races which are heritable. One outlier family which has all 3 races represented challenges simple Mendelian interpretations of MLP races. I review 4 attempts to reconcile the outlier with Mendelian mechanisms, and propose another interpretation, drawing on polygenic mechanisms, treating race as a polytomous liability threshold trait, which is flexible enough to explain all observations in-universe (at least for the first few seasons of MLP).