Earth that was is gone.
Legends speak of an alien attack on the Sol system that ended with the sudden destabilization of the sun and destruction of the inner plants. The outer colonies were blasted with radiation and solar winds. There was just enough time for the survivors to make for humanity's first extrasolar colony, Alpha Centauri.
Today humans are divided into four clades; Terrans, Centauri, Scorpii, and Adams. The Centauri are brutal genetically engineered super-soldiers bent on spoil and conquest. The Scorpii are twisted spacers obsessed with self modification. Terrans are those humans who have been "genefixed", a process that removes congenital conditions and genetic diseases. Adams are those with an undiluted genetic heritage going back to Old Earth.
In the System's Commonwealth the two largest groups of Terrans are the Ryo Federation and Pegasi Caliphate. Here cybernetics and gene modification are restricted to prevent catastrophic genophages. However the Federation allows a wild variety of cosmetic modifications from cat ears to purple skin.
Humans are still roughly divided by ethnic group but due to the destruction of earth the ethno-racial lines became severely blurred before faster than light travel allowed for the great human diaspora.
- Atlantian - mediterranean; italian, greek, macedonian, turkish
- Pegasi - arab, persian, indian
- Ryo - east & southeast asian; from korea to malaysia
- Laurentian - north-american & west european
- Amazonian - south & central american
- Californian - ruso-baltic; named for California Nebula
- Gondwanan - central & south african; primarily bantu, zulu, and yoruba
- Lemurian - oceanic; australian, filipino, maori, samoan, etc.