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

A pair of tour guides from Greece tell us how the island of Crete offers a natural experience unlike any other. Then 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 a Dutch biologist explains how urban evolution is happening faster than we used to think all over the world.