It was Kris Helphinstine's first week teaching at Sisters High School, and he was hoping to encourage some critical thinking in his biology class. So while discussing evolution, he handed out an essay written by a prominent creationist and put together a PowerPoint presentation linking evolution to eugenics experiments practiced in Nazi Germany. That decision cost Helphinstine his job this week. The Sisters School District Board voted to fire Helphinstine after only eight days, making the Central Oregon community the latest flashpoint in the multidecade debate over the teaching of evolution in American schools.