Tracing the evolution of Darwin's theory.

A crew of scientists and historians has left the Belgian port of Ostend aboard a clipper that will copy the expedition that inspired Charles Darwin’s theory of natural selection.

The project is celebrating the 200th anniversary of the naturalist’s birth and is joined by his great-great-granddaughter. Sarah Darwin said as the group set off: “I hope to be looking through Darwin’s 19th century eyes, the places he visited and get some sort of idea of what it was, the series of triggers that brought him to the conclusion of evolution by natural selection.” Darwin’s voyage on “The Beagle” in 1831 took him from Plymouth in England, around the southern tip of South America to the Galapagos Islands. His observations on the natural world formed the basis of his groundbreaking book “On the Origin of Species.”