Bartolomé Island Pinnacle Rock, Galápagos Islands, Ecuador

A not-quite-barren islet

Life always seems to beat the odds here in the Galápagos Islands. Though it's one of the few green patches you'll find on tiny, barren Bartolomé Island, this narrow peninsula with its twin beaches teems with living organisms. More than 500 miles from any mainland, the local flora and fauna not only survive but thrive. When he explored the islands in the 1830s, a young Charles Darwin was inspired by such rich, resilient life: plants and animals much like those found on the mainland, but just a little different. Hypothesizing that even Earth's most far-flung organisms descended from a common ancestor, Darwin would advance these ideas more than 20 years later in his book 'On the Origin of Species,' becoming a pioneer in the field of evolutionary biology.