Polar bears are a great example of natural selection and evolution. But how did this ball get rolling? Remko de Waal/AFP/Getty Images hide caption toggle caption Remko de Waal/AFP/Getty Images Opinion 13.7: Cosmos And Culture Do We Know What Life Is? March 18, 2014 Life, in all its forms, is amazing. Neil deGrasse Tyson captures some of this wonder in the latest episode of Cosmos. But commentator Alva Noë says he also seemed to avoid the biggest question of all.