The Galapagos Islands, which are 1,000 kilometres west of the coast of Ecuador, a world famous

for their unique and fearless wildlife and in particular the giant tortoises after

which these islands are named.

It was his visit here on the Beagle in 1835 that led Charles Darwin to call the archipelago

a little world within itself and set him thinking about how animals and plants change

and ultimately inspired his theory of evolution.

The archipelago is a little world within itself, considering the small size of these islands

we feel the more astonished at the number of their Aboriginal beings.

I'm Sarah Darwin and in this BBC World Service programme I'll be following in the footsteps

of my great-great-grandfather Charles Darwin to see how the Galapagos Islands have evolved

and changed since he first came here 182 years ago.

This is an emotional journey for me.

Galapagos and the theory of evolution are of course deeply embedded in my DNA and inspired

by Charles Darwin, I too have followed a scientific career as a botanist.

But when my great-great-great-grandfather came here he was just 26 and an amateur naturalist

and enthusiast.

Charles Darwin of course came here by ship on the HMS Beagle as part of a long five-year

voyage of exploration that took him around the world.

September 15th, 1835, this archipelago consists of ten principal islands of which five exceed

the others in size, they're situated under the equator and between five and six hundred

miles westward of the coast of America.

So what was so special about the Galapagos Islands that eventually led him to come up with

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