The Galapagos Islands are the perfect blueprint for the evolution of our natural world. While they have existed for millions of years, it was naturalist, geologist and botanist Charles Darwin who put them on the map. Since the publication of Darwin's On the Origin of Species in 1859, the archipelago has become one of the most studied places on the planet. |
The fascinating adaptations of the endemic wildlife of the islands formed the basis of Darwin's theories of evolution, but the history of how the species arrived in the first place is every bit as interesting. For visitors travelling to this unique region on a Galapagos holiday, understanding the details can add immense value to the experience.
The Long Journey to Evolution The archipelago's geographical location affords it an environment unlike anywhere else in the world. The incredibly varied habitat, created by its position at the convergence of three ocean currents, supports a unique and unusual array of plant and animal species.
The First Arrivals
Millions of years ago, when the first of these volcanic islands pushed past the Earth's crust and through the surface of the ocean, they were completely barren of plant or animal life. Because all the species had to disperse here by long distance means, there is nowhere near the diversity that there is on the continental mainland. In terms of wildlife, this means that there are few mammals, no amphibians and an abundance of reptiles; while for botanical species, there are few plants with large seeds or flowers, but lots of smaller ferns and grasses.
Spores of the mosses, lichens and ferns (lower order plants) that grow in such abundance here were carried here by the wind – able to travel the long distances due to their diminutive size. That weight factor explains the dearth of vascular plants, with the exception of some whose seeds are aerodynamically designed to be carried on the wind (dandelions, for instance). Seabirds were also likely to have been responsible for bringing in seeds on their feathers and feet.
Insects, small land birds and bats would have been light enough to blow to the islands in strong winds. There are very few larger mainland bird species here, however, as they would not have the stamina to make the journey alone and were too heavy for wind assistance.
The ancestors of the aquatic wildlife of the islands, like the fur seals, penguins and sea lions, would more than likely have arrived by themselves, with the assistance of the currents. But it is generally considered that smaller wildlife, like rats and various reptile species, arrived clinging to (or tangled in) rafts of vegetation that emanated from the coastline of Central and South America.
The larger plant species, like the iconic saltbushes and mangroves of the islands, produce seeds that are able to withstand high levels of saline, so they too are thought to have arrived on the ocean currents.
Enjoy the Natural History of a Galapagos Holiday
This South American archipelago is truly one of the most fascinating places on Earth. For those who undertake the adventure of a Galapagos holiday, learning more about the islands' unique wildlife and geological history before departure will greatly enhance the experience.
Marissa Ellis-Snow is a freelance nature writer with a special interest in the unique wildlife of the Galapagos Islands. Marissa chooses the expert-led Galapagos holiday itineraries organised by Naturetrek, which have brought her unforgettable sightings of a wide range of wildlife in one of the most spectacular regions on Earth.
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