SCIENCE

Picture of the Week—Pink Iguana

If Charles Darwin had wandered up the side of the Volcan Wolf volcano in 1835, he might have spotted what is now known as the rosada (or pink) iguana

Sarah Zielinski

January 9, 2009

If Charles Darwin had wandered up the side of the Volcan Wolf volcano on the island of Isabela when he visited the Galapagos in 1835, he might have spotted what is now known as the rosada (or pink) iguana. Then again, probably not. It was first reported by some park rangers in 1986. The distinctively colored iguana has never been found anywhere else.

The rosada iguana was recognized as a member of the Conolophus genus of land iguanas (there are two known species in the Galapagos), but how it fit into the evolution of the Galapagos land iguanas remained a question. A yellow iguana also lives on the volcano; could they be the same species?

Now a new genetic analysis of the land iguanas, published by PNAS this week, reveals that the rosada is its own species and one that diverged from the other two about 5.7 million years ago. This was a period before all of the Galapagos Islands had formed, and, strangely, well before the volcano that is now the rosada’s home had formed.

The researchers warn that the new not-yet-scientifically-named species is so rare that it already meets the criteria to be labeled “critically endangered.”