Editing Nobledark Imperium Notes (section)

= Demographics and Life Expectancy in the Imperium =

Because Eldar aren't getting into stupid fights with the Imperium like in canon and the Eldar have other races like the humans and the Tau to have their back, Eldar population are actually going up (though like maybe at a fraction of a percent increase per year), though it's going to be an incredibly long time before their population escapes its "dying race" status.

Without any life-extending medical treatments, Eldar typically live about 1500 years or so. With life-extending medical therapy they live about 4000-5000 years on average. By contrast, humans with rejuvenants typically live for just under 1000 years. However, this process is much more scattershot than for Eldar, and based on genetic compatibility sometimes you get individuals living for 1000-2000 years, like Lorgar or Guilliman. If rejuvenants were standardized and widespread, patterns of genetic compatibility might be more clear, but it is not possible to provide rejuvenants to every human in the Imperium and the really high-quality ones are restricted to important individuals like the primarchs, the High Lords, or Jubbowski. As in canon, being an Astartes and/or a psyker helps. Mark III S Astartes are really crazy in terms of their lifespan, Vulkan having lived for 7000-8000 years and Lion technically still being alive, if in a coma somewhere. Sanguinius might have been outright biologically immortal due to many of the people who engineered him being the same ones who built the Mark III S gene-seed.

So essentially the low end of the Eldar life expectancy bell curve intersects with the average (with rejuvenants) life expectancy, whereas the high end of the human life expectancy bell curve intersects with the average/low average of Eldar life expectancy.

Then you have the pre-Fall Eldar. The ones who had access to the good medical care and life-extending technology the Eldar lost in the fall. Eldrad, at minimum, is over 14,000 years old, and could possibly be older. No one knows how long they can live, though it’s obviously not forever as Eldrad is showing his age and is currently racing the clock to finish his masterpiece before he dies. For obvious reasons, they are a dwindling group, with only a handful around in M41. Eldrad, Vect, Macha, and Lady Malys, among others, all fall into this category.

It’s been mentioned the Tau have started developing their own juvenant technology after meeting the Imperium. Still in its infancy compared to Eldar and humans and so far not super impressive. Major Tau that have survived to M41 have done so through other means. Shadowsun has survived by being in cryostasis most of the time, Farsight has the Dawn Blade, and Aun’Va has been doing…something to keep himself alive, though it’s implied he’s been keeping a low profile to avoid suspicion.