Volcanic activity is most recent in the western islands, making the eastern islands the oldest. The tectonic plates beneath the islands (and subsequent volcanic activity) move at a rate of about 5 cm per year.
Pictured below is the Pink Iguana (colonophus marthae), which is found only on Isabela island. Darwin did not discover the species during his 1820 voyage to the islands; rather, the species was not discovered until 1986. It was at first thought to be the same species as the Galapagos land Iguana, and only in the past few years has it been determined to be a separate species. Although the species is only found on this particular island, experts say the pink iguana is not in immediate danger from volcanic activity; instead, experts are more concerned about the impacts of tourism and non-native species.