The creation and evolution of the Galapagos island

Lessismore.one has arrived on Galapagos!

P9040059_thumb The creation and evolution of the Galapagos island

Galapagos is located on the Nazca tectonic plate. This perpetually moving plate is heading eastward over the Galapagos hot spot and has formed the chain of islands. The islands were formed through the layering and lifting of repeated volcanic action. This geographic movement is correlated to the age of the islands, as the eastern islands (San Cristóbal and Española) are millions of years older than the western islands (Isabela and Fernandina).

Galapagos_map_thumb The creation and evolution of the Galapagos island

Standing on an old lava flow (Isabela)

P9040053_thumb The creation and evolution of the Galapagos island

Each major island, with the exception of the largest island, Isabela, consists of a single large volcano. Isabela was formed when six volcanoes joined above sea level and is the biggest island. Geologically, the Galapagos Islands are quite young, probably no more than five million years old. Some of the westernmost islands, which are the most volcanically active, may only be hundreds of thousands of years old and are still being formed today (Source: https://www.galapagos.org/about_galapagos/about-galapagos/history/geologic-history/). Galapagos Islands consists of 13 main islands and 7 smaller islands, you can read more about the islands here: https://www.galapagos.org/about_galapagos/about-galapagos/the-islands/ If you are planning a visit to the Galapagos, the website as a very detailed description including visitor sites for each island.

Today you can walk in some of the lava tunnels (Santa Cruz) – this is the biggest one

P8301687_thumb The creation and evolution of the Galapagos island

The lava tunnel is 400 meters long it is 4 meters wide and 5 meters tall

P8301693_thumb The creation and evolution of the Galapagos island  P8301697_thumb The creation and evolution of the Galapagos island

The lava tunnel has one narrow passage, where Esben could just slide under (Are you calling me fat????)

P8301708_thumb The creation and evolution of the Galapagos island  P8301718_thumb The creation and evolution of the Galapagos island

Lava tunnel on Isabela that leads out into the ocean

P9056229_thumb The creation and evolution of the Galapagos island  P9050134_thumb The creation and evolution of the Galapagos island

The creation of the Galapagos islands made a unique habitat for animals, that made it all the way. In 1835 Charles Darwin arrived on the Galapagos after leaving England in 1831, with Vice-Admiral Robert FitzRoy, who was the captain of the ship HMS Beagle.

20171008-sammen_thumb The creation and evolution of the Galapagos island

Darwin realized that the islands had only been recently inhabited, when General Jose Villamil from Ecuador founded a colony in 1832. Due to virtually no human settlement, Darwin was fortunate to observe the environment in its pristine, untouched state. What Darwin observed on the islands contributed substantially to the formation of his theory of evolution, where animals changed over the course of generations to become more suited to their environment (Source: http://www.galapagosislands.com/blog/charles-darwins-galapagos-vs-todays-galapagos/).

Darwin’s finches are a group of about fifteen species of passerine birds. The birds vary in size from 10 to 20 cm and weigh between 8 and 38 grams. The smallest are the warbler-finches and the largest is the vegetarian finch. The most important differences between species are in the size and shape of their beaks, which are highly adapted to different food sources. The birds are all dull-colored. Source: https://en.wikipedia.org/wiki/Darwin%27s_finches. During one to two million years the finches dispersed to different islands and eventually diverged into distinguishable populations that adapted to different ecological niches. Over time, these adaptations led to the different species, because the small birds encountered few competitors and the remote location prevented new species from arriving frequently.

DSC04800_thumb The creation and evolution of the Galapagos island  DSC05106_thumb The creation and evolution of the Galapagos island  DSC04791_thumb The creation and evolution of the Galapagos island

Close ups of the beaks

DSC04922-2_thumb The creation and evolution of the Galapagos island  DSC04911_thumb The creation and evolution of the Galapagos island

This finch has specialized in cactuses

DSC05730_thumb The creation and evolution of the Galapagos island

The biggest threat is humans! Agricultural development, introduced plants and introduced predators (cats and rats) are changing the habitat’s of Darwin’s finches. Also a deadly diseases makes the finches suffer. One is called avian pox, which is carried by mosquitoes and infect many bird species, not just the finches. A new treat to the baby finches is a parasitic fly that lays its eggs in the finch nests. The fly maggots suck the blood of the nestling finches, eventually causing their death. The long term effect of the parasitic fly is unknown, but researchers collect the eggs from infected nests, to make sure that the newborn finches will survive.

One more problem facing new plant colonizers to the Galapagos Islands was pollination – many plants rely on insects or animals for pollination, and the chance of both a plant and its pollinator arriving to the islands together was unlikely. This can explain why there are so few showy flowering plants, which mostly require animal pollinators, but there are many wind-pollinated plants in the islands. Many Galápagos plants have small, boring/dull colored flowers with overall poor rewards, being associated with a poor pollinator fauna typical of oceanic islands.

P9012421_thumb The creation and evolution of the Galapagos island  P9012424_thumb The creation and evolution of the Galapagos island  P9012441_thumb The creation and evolution of the Galapagos islandP9012446_thumb The creation and evolution of the Galapagos island  P9012448_thumb The creation and evolution of the Galapagos island  P9090330_thumb The creation and evolution of the Galapagos island

<

p align=”center”>P9106331_thumb The creation and evolution of the Galapagos island

printfriendly-pdf-button The creation and evolution of the Galapagos island

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.