Charles Darwin in the Galapagos
Perhaps our first association with the word "Galapagos" is the name "Darwin." Darwin's visit to the Galapagos Islands had a resounding impact on the formation of his Theory of Natural Selection. A rather unmotivated and failing medical scholar, Charles Darwin accompanied Captain Robert Fitzroy as a travel companion and naturalist on the HMS Beagle. His book the Voyage of the Beagle is an account of his worldwide journey. When setting off from England in 1831 for a five-year voyage, Darwin had little ambitions for groundbreaking scientific research. After surveying the coasts of South America, the ship stopped over in the Galapagos Islands. During his visit to the islands, Darwin noted that the unique creatures were similar from island to island, but perfectly adapted to their environments which led him to ponder the origin of the islands' inhabitants. Among those that struck Darwin so greatly were the finches that are now named in his honor. Darwin would later base some of his thought from the supposing that these finches were all descendents of the same lineage. Years later in 1859, Darwin finally consolidated all of his observations into his famous book On the Origin of Species, drastically and controversially altering the scientific view on the biological origins of life.
The natural history of the Galapagos Islands has fascinated visitors since their most famous guest landed there in 1845. Darwin's observations during his voyage on the HMS Beagle laid the foundation for a theory that greatly impacted western thought: the theory of evolution. Upon rediscovery of the islands, your mind will also reel with delight, leaving you in. Amid the volcanic geography of these islands 600 miles in the Pacific Ocean, plant life takes root in basalt rock, centurion turtles roam and penguins swim in equatorial waters. In the 450 years of human history, the islands have been used as prison colonies, naval ports and research stations.
Biological Evolution of the Galapagos
Whether in the sea staring into the violet straight pupil of an octopus, observing a marine iguana washed by waves gnawing at algae, or facing a serene wizened tortoise-- any visitor to the Galapagos Islands can not help but ponder, "how did such creatures come into existence?" And they would not be the first.
"Considering the small size of these islands, we feel the more astonished at the number of their aboriginal beings, and at their confined range... Hence, both in space and time, we seem to be brought somewhere near to that great fact, that mystery of mysteries --the appearance of the new beings on this earth." Charles Darwin, 1845.
In such a harsh and unforgiving environment, it is difficult to believe that the flora and fauna arriving by chance at these islands had any hope to establish a dynasty of descendents. However the fact remains, bringing more wonder during you tour, that life does exist with such diversity in an environment that seems to offer so little. Certainly, many of the initial arrivals to the islands did not come at an opportune time: at a time without a mate to greet them, without a plant to feed on, without a bit of soil to put down roots. Often, over the millions of years that chance brought birds in a storm, sea lions and penguins in currents, seeds across from the continent, the first life to remain would have been "pioneer" species. These species are those that can exist out of seemly nothing, such as plants growing out of lava. They survive to die and leave their organic material for the next wave of immigrants --feeding the next flora, the next vegetarian creature.
Darwin's observations, specifically on what are now called "Darwin's Finches" and their adaptations eventually provided the basis for his Theory of Natural Selection. At the time, it was a dynamic departure from the commonly held belief that species were static. Explained briefly, the concept of the evolution of species is based on a number of characteristics of survival and reproduction. In most populations, the number of species is larger than the available resources and competition is inevitable. Within the normal variation that occurs in species, occasionally a mutation or difference will occur that will be somehow advantagous to survival or breeding, and those with the positive change will have a greater number of offspring. As the offspring are likely to receive these same genetic advantages, they also will be more likely to survive and pass on their genes. Those best adapted to their environment,most specified and adaptive, will survive.
After years of isolation on the Galapagos, where small populations of a species must have existed, adaptations within that species would be more drastic as there was no large mainstream population to act as a buffer for variations. Often, variations of an ancestor are apparent. The land iguanas of Santa Fe, distinct in their yellow color, like their cousins on other islands, have adapted to eat cactus, spines and all. Their second cousins, the marine iguanas, perhaps adapted to eat from the sea, avoiding the competition on land. The most famous example are the 13 species of Darwin's finches, all stemming from a single ancestor, and adapting to such varying diets as cactus, parasites and even blood. The process of adaptation is well documented in Jonathan Weiner's "The Beak of the Finch," published by Vintage Books.
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