534a Crete; Alaska's Tip of the Iceberg; Darwin Comes to Town

A Dutch biologist explains how urban evolution is happening faster than we used to think all over the world. Plus, travel writer Mark Adams describes his 3,000-mile voyage along the coasts of Alaska to follow what the Harriman Expedition saw in 1899. And we'll hear how the Greek island of Crete offers a natural experience unlike any other.