In Ancient Eurasian DNA we learn a lot of how we came to be different peoples. Where Eurasians in general are concerned, it seems that our origin was in the Middle East, with some influence from other populations, including on two occasions Neanderthals.
Of course over our history as a species we have done a fair amount of traipsing about, and a fair share of race and species mixing. I’ve forgotten what Larry Niven called it, but apparently sexual diplomacy is rather popular with us.
So consider the elves of the land of Purhep, when and how did the Parchap Elves and the Howgrath Elves separate.? Under what conditions did the latter migrate to the Shirin Coast over the Whelbin Mountains and was the concurrent Haf Glacial as big a factor as some scholars say?
Put it in your own words, modify, and have fun with it.