Pink iguanas unknown to Charles Darwin during his visits to the Galapagos islands may provide evidence of species divergence far earlier than the English naturalist's famous finches, researchers said Monday.

A genetic analysis showed that the pink reptile likely originated in the Galapagos and split from other iguana populations some five million years ago when the archipelago was still forming, the researchers said.

The creatures only seem to live near a single volcano at most 350,000 years old, which means the reptiles that grow longer than a meter and up to 12 kilograms must have at one time existed elsewhere in the Galapagos, Gentile said.

"We think the population is very small and there is a great risk of extinction," Gentile said.