Formation of the Galapagos Islands
Home to unique species of flora and fauna, the Galapagos Islands are located on the Equator in the Pacific Ocean, 1000km from the Ecuadorian coast. Having formed from a volcanic hotspot, the result of tectonic plate separation, the 19 islands of the Galapagos are unique in that they have never been part of any other landmass.
In the west, of the archipelago, the islands are born by a combination of volcanic and seismic activity. The younger western islands of the archipelago are mountainous, featuring active volcanoes and rugged, barren terrain. The older islands to the east are flat, green and forested and are gradually sinking beneath the ocean’s surface. Due to continental drift, the islands gradually move to the southeast at a rate of approximately 3 inches per year.
The entire archipelago can be likened to a slow-motion island-making conveyor belt running from the northwest where the islands spew forth from beneath the sea to the southeast where they eventually succumb to the waves. The Galapagos Islands that we visit today are only the latest in a long sequence of islands which, over millennia, have risen from and fallen into the ocean.
Animals of the Galapagos
The Galapagos Islands are positioned at the confluence of three major ocean currents which throughout the year bring warm water along the equator (Cromwell Current and South Equatorial Current) and cold water from the south (Humboldt Current). The combination of geological and climatic influences has resulted in the astonishing biodiversity for which the islands are famous.
The Galapagos Penguin is the only species of penguin found in the northern hemisphere and which breeds in the tropics.
The marine iguanas of the Galapagos are the only marine lizard species in existence.
The flightless cormorant is free of land predators and with little need to fly, over time it has evolved stunted wings which are incapable of flight.
Finches throughout the islands have evolved beaks of varying sizes and shapes to facilitate consumption of island-specific foodstuffs.
Giant tortoises have evolved different shell shapes on different islands of the archipelago. One subspecies, predominantly found in drier locations, has a high neck arch which enables the tortoises to extend their necks and feast on low hanging tree branches.
The Galapagos Islands’ name originated with early Spanish seafarers who likened the giant tortoise shells to a type of Spanish saddle, the galapago.
Charles Darwin and The Origin of Species
In 1835, during his expedition on the HMS Beagle, young geologist and biologist Charles Darwin visited the Galapagos Islands. Fascinated by the relatively young age of the Galapagos Islands, Darwin’s observations of the similarities between species, particularly mockingbirds and finches, likely inspired his initial musings on evolution.
Influenced by Lyell’s theories on geological time and Malthusian theories on population and the struggle for survival, on the journey back to England, Darwin began formulating a theory which was to revolutionize the world. His theory was that all species – including humans – were not “fixed” but had evolved over time. His work refuted the commonly-held belief that all life on earth had been created by a deity.
Anticipating the reaction that his theory would receive from friends and colleagues within the scientific community, to say nothing of the theological implications, Darwin took great pains to ensure the accuracy of supporting evidence for his work.
The catalyst which finally prompted Darwin to publish an abstract of his work was a letter from scientist Alfred Russell Wallace which outlined his own independently-developed theory of natural selection. Darwin was encouraged by his friend Lyell, to publish his work immediately so that his work was not eclipsed by Wallace’s planned publication. Today, both Darwin and Wallace are considered co-founders of the theory of evolution by natural selection.
In 1859, more than 20 years after he had visited the Galapagos Islands, Darwin’s masterwork was published: On the Origin of Species by Means of Natural Selection. In subsequent editions it was entitled The Origin of Species. Since publication of the first edition, the book has never been out of print.
The idea that “man had evolved from apes” and not divine creation was a notion ill-received by the church and soon after the publication fierce debates raged between scientists and clergy. They continue to this day.
© Absolute Latin America Tours