Average Male Height: 6' 2"
Average Female Height: 5' 11"
Age: 900,000 Years
No one is entirely for certain where the Hyperboreans came from. But there is something we do know, Hyperboreans are the ancestors of all known hominids. It turns out that, in this alternate reality, humans were pretty much on the dot when it came to figuring out their evolutionary history, only they were off by a few thousand years. It turned out that the genus Homo included more than just Sapiens, Erectus, & Neanderthalis. It also included the more ancient elves & dwarves of a lost but unforgotten era.
Though Hyperborea's oldest relatives date to Spain & Egypt during the last Ice Age, most of them lived through out Europe for the first 25,000 years of their existence. Then it all changed when they settled on an Island in what is now the North Sea that contained wealth & resources of immeasurable quantity. It was enough to start the world's first Empire. That land would one day be remembered by the ancient Greeks as Hyperborea, a paradise locked away in the frozen north. Through peaceful negotiation as opposed to savage action, Hyperborea managed to spread through out the world, & divided into many different sub-species, races & cultures.
Durring the period known by scholars as "The Age of Experimentation", Hyperborea contemplated the possibility of granting her citizens & allies the newly discovered gift of Biological Immortality. As a result of this drastic change, they created a new generation, & modified the generations before to be a completely different group of animals than what had come before. They've converted their neurons throughout the entire body to serve a dual purpose, basic neurological functions as well as memory storage, giving them a near limitless supply of memory. Men & women are only capable of getting another pregnant, or becoming pregnant a certain time of the year, drastically limiting excessive birth rates & over population. Age preventative genetic make up similar to what's found in Mole Rats & Hydras. These and other genetic modifications followed in this tremendous period of growth & prosperity. When they finally made it to the Hollow Earth, they became & have remained the dominant culture in Tarkaria.