Stranded cruise passengers become humanity's ancestors
In 1986 a global financial collapse strands the 'Nature Cruise of the Century' ship Bahía de Darwin, and its incompetent captain Adolf von Kleist runs it aground on the fictional island of Santa Rosalia with a few passengers. These include widowed biology teacher Mary Hepburn, the pregnant Hisako Hiroguchi, and six girls of the Kanka-bono tribe. A bacterium that eats human eggs then sterilizes everyone else on Earth. Mary secretly inseminates the Kanka-bono women with the captain's sperm, so this accidental, unselected handful becomes the entire founding stock of the human race.
