The Galapagos Islands have developed a unique marine ecosystem and rare flora and fauna due to their isolated location and diverse environmental conditions, which had a major impact on Darwin’s theory of evolution.
The Galapagos Islands are located in the Pacific Ocean, about 1,000 kilometers off the South American continent, and the 19 islands and surrounding marine protected areas make up a unique marine ecosystem that has been called a “living museum and exhibition of evolution. It’s also known as a treasure trove of marine life because it’s where three ocean currents meet. Ongoing earthquakes and volcanic activity show how the islands were formed. This formation and isolation from other islands has contributed to the development of rare animals in the area. Examples include land iguanas, Galapagos tortoises, and various species of finches. These creatures were a major inspiration for Darwin’s theory of evolution when he visited the islands in 1835.
The Galapagos Islands are located on the Galapagos Submarine Platform and consist of about 120 islands. The main islands include Isabela, Santa Cruz, Fernandina, Santiago, and San Cristobal. The area was formed by volcanic activity, with the summits of the volcanoes rising about 3,000 meters above the Pacific floor. There has been strong volcanic and seismic activity in the western part of the archipelago. The main islands are composed of gently sloping stratovolcanoes, which are characterized by collapsed craters and calderas.
The long coastline is somewhat disintegrated, but there are many steep cliffs and beaches of lava, coral, and shells formed by faulting and marine erosion. Notable features include crater lakes, fumaroles, lava tubes, lava caves, sulfur areas, and various volcanic rock formations, with pumice, ash, and tuff still spewing from craters. The marine environment is also unique and highly diverse, with water temperature and nutrient composition varying with the amount of light penetration. The diversity of the marine environment is due to the warm water temperatures caused by the influence of active upwelling currents (equatorial gyre) and subtropical currents (Peruvian Current).
There are large differences in elevation, area, and orientation among the islands, and their physical separation from each other has resulted in certain species being endemic to specific islands. Coastal vegetation is mainly found on beaches, around brackish lagoons, and in coastal lowlands with rocky sand. Swamps and lagoons with mangrove trees are now protected. As you move inland from the coast, you’ll find the dry zone, which is the climatic condition found in most parts of the archipelago.
The humid zone builds on top of the dry zone, and there is also a transition zone where the two climate zones meet. The wet zone is a very humid area, covered in thick fog, or garua, that can retain enough moisture during the dry season. The fog builds up mainly at night and flows into the forest daily. The tops of the large islands are covered with ferns, rice plants, and sedges, which are kept moist by temporary pools of water.
The endemic fauna of the Galapagos Islands includes invertebrates, reptiles, birds, and a few species of endemic mammals. With the exception of two species of sea turtles, the reptiles are all endemic. The Galapagos gopher tortoise has 11 subspecies, depending on the island, and is critically endangered. Other species include land iguanas, marine iguanas, three species of whip snakes, and several species of lizards and lizardfish. The Galapagos is home to 57 species of birds, 26 of which are endemic and 31 are migratory. Endemics include 13 species of Darwin’s finches, including the Floriana tree finch and mangrove finches.
Other notable species in the Galapagos Islands include the Galapagos deerbird, flightless Galapagos cormorant, Galapagos penguin, lava gull, Floreana’s mockingbird, Galapagos wagtail, Galapagos egret, nocturnal swallowtail gull, Galapagos moxie, toucan, Galapagos swallow, and Galapagos pigeon.
There are six endemic mammal species: the Galapagos fur seal, Galapagos sea lion, two species of rice rats, and bats and old man bats. The marine fauna includes sharks, rays, and several cetaceans. Green and hawksbill turtles are often seen along the coast, and sea turtles build their nests on the shoreline.
