We know that extinction means systems-collapse more than the retirement of one character in the show, but counting species remains a good unit measure of that systems-collapse. Likewise, the systematic gathering and archiving of DNA in seed banks and in zoos may enable an eventual re-seeding of the planet. This would not be an inversion of extinction and a restoration of the Holocene, but the cultivation of alternative ecosystems from these genetic codes.
random seed words vs. csprng with time as an irretrievable variable