The Galapagos Islands are truly a unique place on earth where Charles Darwin changed the world forever with his theory of evolution through natural selection. I recently went to the Galapagos Islands with my wife on a guided tour that was extraordinary.
Galapagos Islands-Geographic Isolation Creates Different SpeciesLocated 600 miles off the west coast of Ecuador in South America, the Galapagos Islands are a UNESCO natural reserve for its unique environment and wildlife. Numerous animals and plants that inhabit the island are endemic, meaning that the species are unique to the islands, appearing nowhere else on earth. The Galapagos Islands are an isolated volcanic island chain created by a hot spot in the earth’s mantle (same as Hawaii). Species on islands such as the Galapagos are forced to grow and adapt to the islands’ unique conditions and if they have the genetic material that allows successful adaptation, then the species will reproduce and prosper, passing on the successful genetic material. In this way a species will evolve useful adaptations.
Giant Tortoises-Great Example of Natural SelectionGiant Tortoises are a perfect example of a species that grew and successfully adapted in isolation from its mainland cousins. It is believed that tortoises arrived on the Galapagos Islands by rafting on floating trees or vegetation that was blown to the islands by way of large storms hundreds of years ago. Upon arrival to the islands, tortoises quickly found luscious leafy plants with no competitors that ate the same food. In addition, they were no predators to tortoises due to the isolation of the islands.
Galapagos Islands -Giant Tortoises
Therefore with no predators and no competition for a large and luscious food source, the tortoises adapted to these optimum conditions to grow to their immense size and weight. Galapagos tortoises commonly grow to 250 kg and often age to greater than 100 years. The tortoise shown in the above picture is over 100 years old.
With these unique and favourable conditions, it seemed giant tortoises were destined to thrive for a good many years, that is until humans arrived. The islands were discovered by a spanish bishop in the 1800’s on an expedition that was blown off course during a storm. From that point onward the islands were used by pirates, sailors and whalers as a food source. Giant tortoises have an extremely slow digestive system and are capable of going without food for up to a year. Unfortunately, this fact almost lead to their demise. Giant tortoises were hunted at will by pirates, whalers and sailors requiring a fresh food source over long voyages on the sea. Tortoises were taken by the hundreds, stored on-board their ships upside-down and then used for food when needed.
In addition to this human slaughtering for food, tortoises were also endangered by other species that came along with man and introduced by accident and on purpose. The numerous problem species introduced by man include goats, rats, dogs and cats. These species on the mainland are no problem, but in an island setting they pose a serious threat to tortoises. Goats eat everything and pose serious completion for food. Rats and pigs are also a serious threat because they eat turtle eggs. Dogs and cats would also kill young turtles preventing them to reach adulthood. Combined with the constant slaughtering, the Galapagos tortoise seriously faced extinction.
This practice continued for so long it almost lead to the complete extinction of giant tortoises from the Galapagos Islands. Ironically, tortoise numbers are now recovering due to the actions by man. Things are quite a bit different now. In the picture above we have two females that are doing quite well.
Ecuador now owns the Galapagos Islands and has made them a natural preserve. All species on the island are now protected and their numbers are recovering with the help of several breeding programs.
The first step in the preservation of any endangered species is through awareness. The message regarding the species at risk MUST get out to the world, and the best way to get your message out, is through a blog. When you get your own blog, we help you promote your message to the world.
Maddalena Environmental Inc.