Why is Galapagos wildlife so unique?

Isolated, inaccessible & untouched

The Galápagos Islands lie around 1,000km west of the mainland Ecuadorian coast. These volcanic islands have never been attached to Ecuador, nor anywhere else for that matter, and have always remained isolated in the Pacific Ocean, straddling the equator. The oldest island, Española, is the furthest south and thought to have been formed around four million years ago. The youngest island, Fernandina, is a mere 500,000 years old, and also an active shield volcano that erupted as recently as 2018. Thanks to their volcanic nature and humidity, the northerly islands are fairly fertile with plentiful vegetation. The islands further south of the equator are more arid with little or no vegetation.

Via numerous known and unknown methods – including floating on vegetation from South America – land animals have made the 21 main islands of the Galápagos their home. Due to the differing island habitats, several species, including tortoises and land iguanas, evolved in a different way to those on neighbouring islands, forming sub-species. This is what Charles Darwin discovered when he visited the islands in 1835. Species of finch, mockingbirds and tortoises, for example, were different from one island to the next. They had evolved to suit their environment and, in so doing, had become unique to the Galápagos. Darwin’s book The Origin of the Species was published some 20 years after his visit, and through this work he had, inadvertently, put the untouched islands of the Galápagos, and their inhabitants, firmly on the map.