“The black Lava rocks on the beach are frequented by large (2–3 ft [60–90 cm]), disgusting clumsy Lizards. They are as black as the porous rocks over which they crawl & seek their prey from the Sea. I call them ‘imps of darkness’. They assuredly well become the land they inhabit.”
A visit to Galápagos is an expedition, a chance to walk in the footprints of Charles Darwin. It’s not about the beach; it’s about the birds, fish, and animals, and simply put, there is no better place on the planet to see wildlife up close than here. A rugged paradise where the air, land, and sea are home to species found nowhere else on earth. It is a zoo without cages: each island is its own unforgiving laboratory of evolution, adaptation, and competition where the fittest fight to survive.
The Kingdom of the Marine Iguanas
Marine Iguanas are perhaps the most striking example of evolution in the Galapagos. As the world’s only seafaring lizard, they began life ages ago as land-going iguanas. Thousands of generations later, the island species no longer even resemble their distant cousins on the continent.
In reality, there are no species that are truly native to the islands. The islands were never connected to any continent— every resident reptile, mammal, bird, and fish arrived after the islands were born of thunderous volcanic upheavals in the deep crevasses of the Pacific Ocean. Once these animals found themselves stranded on these rock strewn, desolate islands, survival dictated the long process of adaptation.
The marine iguanas—stoic black dragons that seem to have crawled out of the volcanic rock itself share the lordship of these islands with the birds, tortoises, and sea lions.
The iguanas are marvelous examples of adaptation. Land Iguanas also exist on the Galapagos and are closer, yet still distant relatives to iguanas on the South American continent. The land iguanas eat spiny cacti with ease and don’t venture into the chilling waters of the Pacific. It’s estimated that around 8 million years ago, a brave land iguana began entering into the surf to eat algae before the chilling waters chased the cold-blooded creatures back onto the sunny beach to heat up again. Little by little, spanning hundreds of thousands of generations, the iguanas were able to develop several adaptations that enabled them to survive chilling temperatures and a new diet such as:
1) A black color that simultaneously camouflages them on the black volcanic coastline and enables them to more quickly absorb the sun’s heat after a cold dive. Some subspecies, notably on Espanola island reveal red and turquoise tones as they’re sunning,
2) Blunt noses for efficiently grazing seaweed on the seafloor,
3) More powerful limbs and claws for climbing and holding onto rocks even as waves pummel them as the enter and exit the sea,
4) Flattened tails for improved swimming efficiency,
5) Improved thermal stability enabling them to survive a 15 degree drop in body temperature,
6) Large nostrils that are used to blow salty water into the air, thus reducing the salinity of their body.
Luckily for a visitor to the Galapagos, the Marine Iguana is present on all of the islands and can commonly be seen sunbathing on the beaches and lava-covered shorelines. Undoubtedly, they’re one of the many highlights on a trip to the Galapagos Islands.