Galapagos Evolution became a Worldwide case study after Charles Darwin's visit to this Archipelago.
The voyage in 1835 to the Galapagos helped Charles Darwin formulate an astonishing theory. He concluded that flora and fauna evolve over time in a process of natural selection. The species to survive would alter based on environmental conditions.
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The Galapagos Islands provided ample examples of adaptation for young Darwin. One example is the 13 species of finch collectively known as Darwin's Finches Each originating from a common ancestral species developed its own traits over years in order to compete for survival within its environment.
Darwin's observations on Finches birds eventually provided the basis for his Theory of Natural Selection, which is referred as the survival of the fittest.
That is that members of a particular species with positive physical or behavioral qualities would be more likely to survive and reproduce than others. Thus the positive characteristics would be passed on.
The most important qualities would be for example, strength, aggressiveness, fertility, pigmentation and intelligence etc.
Species therefore become modified by the gradual accumulation of new or changed characteristics. These changes are now known to be the result of genetic inheritance and mutations.
Charles Darwin said: "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."
Plant seeds can be carried by both air and ocean currents, although most were probably brought by sea birds.
The Galapagos Islands are well located for receiving long-range immigrants, both ocean and air currents (Northeast and Southeast trade winds) move out into the Pacific from the South American mainland, thus the potential for carrying organisms is increased.
Some of the first species to arrive may have been bacteria and the minute spores of plants such as algae, fungi, ferns, mosses and lichens.
These plants not only have spores that are easily dispersed by the wind, they also have the ability to grow without a lot of organic material.
Such plants are known as pioneers or colonizers they not only survive, but also thrive in hostile conditions and eventually provide organic matter, or humus for higher plants.
The seeds of larger plants are more likely to have arrived within the digestive systems of birds, or attached as part of natural rafts.
Some seeds also stick to the feathers and wings of seabirds, and of course most coastal plants such as Mangroves, Salt Bush, Galapagos Cotton etc. have seeds that float and are salt tolerant.
It is incredible to believe that in such a harsh and unforgiving environment, the flora and fauna arrived by chance at these Islands.
It seemed that they didn't have any hope to establish a dynasty of descendants.
However the fact remains, that life does exist with such diversity in an environment that seems to offer so little. This is amazing!
The Galapagos evolution of these Islands is from a volcanic origin. There is a geological hotspot deep in the earth's crust underneath the Pacific tectonic plate where magma flows to the surface.
The hotspot remains stationary. However, as the Pacific plate moves from west to east, new volcanic Islands begin to appear beneath the sea until they eventually poke above the surface to create a new Galapagos Island.
The youngest of the Islands is Fernandina Island which is the westernmost Island. It is estimated geologically to be 800,000 years old. The oldest Islands off to the east are estimated to be 3 million years old.
Marine animals such as sea lions, fur seals, sea turtles and penguins are all good swimmers and probably made their way to the Archipelago aided by favorable currents.
Also Galapagos Island Tortoises can float for a considerable length of time, and may likewise have been swept across the sea by ocean currents.
Other land animals could only have arrived on natural rafts like single tree trunks or big floating loads of vegetation broken loose from riverbanks and swept out to sea during floods.
Since the Galapagos Islands evolved with no human interaction, the wildlife does not have that natural fear for humans that common animals have in other places of the planet.
Viewing the Galapagos wildlife is a wonderful and fun experience.
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