My state (Tripura) originally had a mostly mongoloid-feature-possessing population (ethnic group: Tripuri). Recently a large number of non-mongoloid people (ethnic group: Bengali) have migrated to Tripura. Assuming that reproductive barriers are not present between these two subpopulations in future, are epicanthic folds likely to be a prominent feature of the new hybridized population?
In this newspaper article, an anthropologist is cited as saying the following:
Poirier attributes the fold to pleiotropic genes--single genes that control more than one characteristic or function--but he has no explanation for its origin