One hundred and seventy-four years ago, Charles Darwin first set foot on the Galapagos Islands aboard the Beagle. Since then, the islands and the unique species they house have been a source of inspiration for many an evolutionary biologist. Even so, it is gratifying to see that even now, on the bicentennial of Darwin’s birth, the Galapagos have not yet finished yielding their secrets.
During Darwin’s five-week stint on the Galapagos, he observed two types of iguana. One was a marine version that, uniquely for lizards, swam and fed in the ocean, and the other was a cactus-eating landlubber, which we now know to be two separate species. But Darwin’s adventures never took him as far north as Volcan Wolf, the northernmost volcano of the large Isabela Island. And that’s why he never described the distinctive pink land iguana that lives only on that volcano.
To be fair to Darwin, even scientists who actually visited Volcan Wolf failed to spot the pink land iguana for the better part of a century. Despite its striking pink head and black-striped flanks, it was only discovered when park rangers accidentally stumbled across it in 1986. They must have thought that they were the victims of some elaborate practical joke.
Atheists will no doubt chuckle at the existence of a pink animal that’s so hard to find it may as well be invisible. The fact that it lives in the Galapagos of all places is just the icing on the irony-cake. But I digress.
The elusive iguana has since been christened the “rosada” form, after the Spanish word for “pink”. And according to Gabriele Gentile, it’s a species in its own right, genetically distinct from the more common yellow versions. Gentile’s team of international scientists from Italy, the USA and Ecuador have analysed the pink lizard’s genes to show that it is a relict, older even than many of the current Galapagos Islands themselves.