(5x01) Pantheon Genesis: Part 1, Episode 1
Metis narrates, to the equivalent of a television interviewer in some future Pacifica, her life's story, addressing her supposed claims to be the very goddess Metis herself. She tells them that according to her mother's account when she was very young, it all began in the late Pleistocene era, when an alien being called Keius modified two primitive humans, her grandmother Keie and then her grandfather Oron, imbuing them with nanotechnology that makes them effectively immortal by constantly rebuilding their bodies to a fixed template. (While still young and developing, these immortals had to eat a special food that would continually reset the nanites, to allow normal growth and development; a food remembered variously as "xian-gu", "soma", "ambrosia", or "tree-of-life" by various ancient mythologies, Metis narrates). Keius did this for unknown purposes, as he suddenly abandoned them without adequate explanation before their training was complete, leaving Keie on Earth among the people of the Pontic-Caspian Steppe, and Oron alone on Keius' starship. (For this reason, Metis narrates, they are remembered by various ancient mythologies as an "earth mother" and "sky father" pair, such as Geie and Ouranos, whose names are corruptions of their true names).
The little that Oron knew of his purpose was that it involved cataloging observations of the people whom Keie lived among, which he could access through a psychic link giving him the ability to read her mind. To that extent he had received rudimentary training in the computer systems of Keius' starship. With that rudimentary training he was able to teach himself more of how to operate the ship's controls. With those new skills he modified the use of a special transporter, through which he had been trained to deliver their special food (which was purposefully designed to grow only under special controlled conditions, not wild on Earth) to Keie, to instead bring Keie herself up to the ship with him, so he would not be so alone.
Being barely-adult humans with no direct orders to do otherwise, the young immortals did what young people do, and started mating. The first of their children was Metis' father, Osan. Next was her mother, Teth. (Metis, in the interview, hand-waves away the uncomfortable implications by noting that, either through the nanotechnology or the genetic engineering that created them, there have never been any complications from recessive defects in her people). After that were, over time, another ten children, five more boys and five more girls, lastly Metis' aunt Rhea and then her uncle Kron, before grandmother Keie finally said that enough was enough of childbearing. (Those twelve siblings, Metis narrates, are remembered by various ancient mythologies as the first generation of gods, under names such as Titans or Giants). By the time Kron was born, Metis' parents were old enough to have paired off themselves, and soon the first of the third generation, Metis herself, was born, though she was known then only as Met.