By the way, if the header to this page is giving you a headache. If you're still stable, read on. If not, well, join the club. The reason being that sometimes I go for long periods of time without coming up with anything. This will hopefully make it easier to deal with.
Humans perfect genetic engineering.
Perfect humans are created and promptly take over the planet. Genetically perfect humans on Earth create Artificial Intelligence. Which promptly takes over the planet. AIs declare war on Martian humans. Martian humans, with backward technology and dauntless courage, destroy the AIs.