One flower that captivated Darwin was the Madagascar Orchid, with it's
eleven inch-long receptacle. He predicted that
somewhere in Magagascar, a place he never visited, must live a moth with a
proboscis eleven inches long, adapted to harvest the orchid's nectar. Forty
years later, two entomologists revealed the discovery of a Madagascan sphinx
moth, confirming Darwin's forecast. Such mutual adaptation -- the moth to the
flower, the flower to the moth -- is called co-evolution.