Board Thread:Lore Discussion/@comment-8248675-20140104003507/@comment-24358064-20140105202336

This is established canon. As per Notes on Racial Phylogeny and Biology, race is inherited through the mother, and only through the mother. In addition, some traits may also be inherited from the father, so for example the son of an Altmer mother and a Bosmer father would be a Bosmer but maybe a bit smaller than Altmer average. That is how the Bretons came to pass: They are in fact human, but with some traits inherited from the Altmer. Same, the other way round, for the Bosmer. So how hybrid races can come to pass is well attested. But there are no classical half-elves as can be found in many other fantasy settings.

As for Jagar Tharn, that was in Arena, before most lore was established. By now this mechanism is in fact established canon, and I'm not sure what there is to argue about.