I actually asked this of the devs recently and got this answer:
What are the general life expectancies of the various races?
Present Day? Immortal. Before? Humans, Half-Giants, Saris, and Sslik 60 to 100 years. Elves, Dwarves, Dryad, Gnomes, Satyr 200 to 250 years. Dragons, many hundreds.
I do not know if "immortal" means that everyone in the living races becomes gifted when they die, or just that only gifted rate notice. It's also not clear to me if there are still children born among the living races.