Galapagos Notebook

Did you know that marine iguanas have two penises? That the temperature at which their eggs incubate determines the gender of a giant tortoise? That a female parrotfish can change into a male? Two weeks in the Galapagos and I’ve climbed volcanoes, swum with penguins, and worn out my shutter-finger photographing sea lion pups. I’ve also become a mound of wildlife trivia. It’s Darwin’s fault, of course. To celebrate the 150th anniversary of On the Origin of Species, I took a berth on a latterday version of The Beagle to retrace the great man’s steps. Crippled by seasickness for most of his voyage, Darwin wrote: ‘I loathe, abhor the sea and all ships which sail on it.’ But then his Beagle was a cramped ‘coffin’ brig with limited rations. Mine is a 105-foot luxury yacht with power showers and a good line in caipirinhas.

‘Darwin’s Finches’ have exaggerated fame. Instead, inspiration for his theory of evolution came from the mockingbird. Before I left I had lunch with Darwin’s charming great-great-grandson Randal Keynes. He explained how Darwin encountered a mockingbird on San Cristóbal which was dissimilar from those on mainland South America. On Floreana, 50 miles away, he found a second mockingbird which was different again. Darwin was struck by the possibility that the birds might be endemic to each island, and mused that this would throw into question the stability of species. While the Floreana mockingbird was wiped out in the 1880s, genetic analysis of Darwin’s specimens has confirmed that those on two nearby islets, Gardner and Champion, are direct descendants. There are around 100 breeding pairs left. Keynes is working with the Charles Darwin Foundation to try to restore the species. ‘The Floreana mockingbird was the clue to the theories which transformed our understanding of natural life,’ he tells me, waving his spoon aloft, his soup untouched.