Scott Carrier in Salt Lake City with the latest installment in his 12-year quest to chase down and catch an antelope. This story and others are included in his book Running After Antelope.

Ira interviews Bob Helms, creator of the zine Guinea Pig Zero, which is about people who make their living by donating their bodies to science for medical experiments. Bob says he wouldn't do spinal tap studies or psychoactive drugs (he calls the people who do the latter "brain sluts").

Anthropologists agree that humans stopped being animals when they started walking upright, on two legs. But scientists don't agree on why our ancestors did this.