A showcase of evolutionary biology

Formed by a series of volcanic eruptions several million years ago, these remote islands were seeded with life by animals drifting across the ocean from the rainforests of Central and South America. Arguably, no other place on Earth can compete in terms of unique wildlife experiences. Not only are there many endemic species here, but they have evolved without mammalian predators and are for the most part unafraid of humans.

It was the naturalist Charles Darwin who put these paradise isles on the map, visiting in 1835 and noting the differences between subspecies on the various islands. This led him to develop his theory of evolution driven by natural selection, outlined in his seminal work On the Evolution of Species. Today, the Galápagos is sometimes referred to as an ‘open air laboratory’, attracting evolutionary biologists and wildlife lovers alike.

Iconic animals

The Galápagos archipelago is famed for the presence of some unique subspecies, with the giant tortoise and the iguana being perhaps the two most well-known. The islands feature diverse habitats, from arid and dry and covered with cacti, to lush-green with wetter microclimates. This forced animals to branch off into several subspecies in order to adapt to natural conditions.

Land iguanas, for example, have evolved into three separate subspecies. These include a marine variety which can deep-dive and forage on the seabed, and the yellowish-brown Santa Fe iguana, which remains land-bound. Similarly, ten varieties of endangered giant tortoises can be found. Besides these iconic species, there are many more that are endemic, including Galápagos sea lions and fur seals which laze upon the shores of several islands.

Adapting to a watery world

Marine iguanas have evolved adaptations allowing them to swim underwater and graze submersed vegetation, making them the only reptile anywhere in the world with this ability. To do this, their hearts beat more slowly than their terrestrial cousins and the blood vessels under the skin constrict. Their snouts have shortened, and small tricuspid teeth have developed to facilitate nibbling algae from rocks. Furthermore, they possess enlarged supraorbital glands to extract salt from their blood, which they then forcibly sneeze out.

A plethora of avian and marine life

As we cruise around the Galápagos archipelago, we’ll be on the lookout for the many species of bird which live here. From Galápagos Penguins and the magnificent Galápagos Albatross – which only breeds on Española – to red-throated Frigate Birds and three species of booby. It’s even possible to spot flamingos on some islands.

The beak that inspired a book

Darwin noticed that of the 18 species of finch he encountered in the Galápagos, each had a different type of beak. He theorised they must all have descended from a common finch found in South America, and their beaks had adapted to eating different types of seeds on the diverse islands. Detailed drawings were made, and exact measurements taken. It became clear to Darwin that bigger beaks were for bigger seeds, and vice versa, inspiring his theory of natural selection.

One of the few endemic predators is the Galápagos Hawk, which preys on smaller birds and young iguanas. Predators can also be found in the seas, with white tip reef sharks, tuna and spotted eagle rays thriving not far offshore. Other aquatic creatures, such as the Galápagos green turtle, can sometimes be seen when snorkelling, while some 24 species of cetacean have been recorded within the Galápagos Marine Reserve.

Ol’ blue feet

The most noticeable feature of sula nebouxii – commonly called the Blue-footed Booby is – yes – it’s blue feet. The colouration is due to carotenoid pigmentation caused by eating fresh fish. These pigments signal health and, in particular, the bird’s immunological state and overall fertility – with a bright blue hue signifying excellent health. As such, the blueness of a booby’s feet is a trait for sexual selection – which is why they exultantly wave their webbed feet in the air during courtship rituals.

A visit to the Galápagos will reveal an incredible diversity of wildlife with much of it unafraid of humans. As such, guests will be instructed in how to remain at a safe distance, ensuring we do nothing that would otherwise disturb the unique creatures and ecosystems in these remarkable island havens.