Board Thread:Lore Discussion/@comment-2165692-20140531154239/@comment-24999978-20140601130521

If this helps:

1. Atmorans, as the name implies, were humans who returned to Tamriel from Atmora. The Nedes, on the other hand, are more native and didn't really leave Tamriel.

2. Do you mean whether or not their interbreeding led to Cyrodiils, Nords etc? If so, to an extent. The Nords are the 'purest' strand of Atmora, whereas the Cyrodiils are descended from Atmorans who interbreed with Nedic tribes further south. The Redguards, however, are descended from the Yokudans, but I'm sure over time they've interbred a bit with other humans (particularly the initial Ra'Gada warrior wave) but not really enough to be noticeable or influence their ancestry. The Bretons also have Nedic blood, resulting from Man-Mer breeding in the First Era.

3. They are quite similar, compared to some of the other races in Tamriel, but I suppose it would be because of the different climates they have become accustomed to and the varying levels of Atmoran blood.

4. The Redguards are, primarily, descended from a strand of the Wandering Ehlnofey who settled on a continent to the west of Tamriel, called Yokuda, before returning after a cataclysmic event (likely caused by the Ansei) destroyed most of Yokuda. There's still a few remnant island chains though.