Galápagos Islands - the Birth of the Theory of Evolution

Volcanic cones on Espanola Island

The Galapagos islands are part of Ecuador and are about 1000 km off the coast of South America. There are 13 major islands and 7 smaller  islands. The islands were all formed by a volcanic hot spot in the Pacific Ocean. The Islands are on the northern edge of the NAZCA tectonic plate and this plate is moving at the rate of about 2 cm a year. Over time the islands have moved off the hot spot as the plate moves. Isabelle island is currently on the hot spot and there is substantial volcanic activity on that island. This is the youngest island and is still being formed.

The islands are influenced by three major oceanic currents. The very cold Humbert current comes from the South and is responsible for bringing penguins and fur seals from Antarctica to the Galápagos. Yes - there are penguins on the equator! The very plentiful  Galápagos sea lions where brought in with the warm current which comes south from California. The final current is a deep ocean current which comes from Australia. There is very little in the way of fresh water on these islands and this is probably the main reason that they have not been developed much and have remained in isolation since they were formed.

Interesting rocks

Sea lion on the beach.

The  oldest of the islands is South Plaza at 4.2 millions years followed by Espanola Island at 3.2 million years old. The main islands are Isabella island which is the largest, Santa Cruz, San Cristobal, Fernandina, Santiago, Floreana, Espanola and Marchena islands.

The islands where first discovered by Father Tomas Berlange in 1535 who was carried there by the strong ocean currents. He describes the desolate islands with very high temperatures and the millions of black iguanas running around and he was convinced that he had discovered Hell. He thought that the black iguanas were the soles of the departed! Later the islands were discovered by pirates and whalers. They decimated the giant tortoises which live on the islands for food and water.

The most famous visitor to the Galápagos must be Charles Darwin in 1835. He was a young naturalist on a round the world voyage on the HMS Beagle from 1831 to 1836. He noted that the populations of animals and plants on the islands had been isolated and that although they were very similar, that had changed as a result of this isolation. This lead Darwin to propose his theory of Evolution, which is probably still today one of the most controversial theories. Not that it should be! His theory is that if a species is in isolation, any mutations in an individual which benefits the survival of the individual will be kept in the population as the individual with the benefit will have the best chance of breeding. This is called "Survival of the fittest". Darwin noted that certain species, such as the Darwin finch are very similar to each other on different islands but differ from island to island where the population has been isolated.
So, basically Galápagos is a unique environment. Due to the inhospitable conditions, the islands have remained relatively untouched by man. The isolation of the animal and plant populations on different islands have, over time allowed for the development of similar but different species of animals, birds and plants on the different islands. Also because man has not destroyed the islands, the animals and birds have no

fare of humans  so you can get really close to them - although the naturist guides go to great pains to make sure you do not get too close.
A truly unique place.
I did a short tour to the Galapagos islands on this trip. It has always been on my "Wish list" and as this was my third (or maybe even my fourth) trip to Ecuador without visiting the Galapagos, I decided it was time to good there. A really great trip. I managed to see most of the species I was interested in seeing!