Jaiwan was a planet that was considered to be a backwater world.
When Bernice Summerfield was 21, she managed to get a job as the assistant field director for an archaeological dig on Jaiwan. She discovered that the native potfish spiders were the devolved descendants of the planet's original sentient inhabitants.
Ten thousand years before the dig, there had been two factions of spiders on Jaiwan, the Alpha Culture and the Omega Culture. The Omega faction wanted to be rid of the Alphas, so they diverted an asteroid to strike Jaiwan and cause an extinction event, going into hibernation before the collision. (PROSE: Genius Loci)