Galapagos Wildlife Evolution
What pattern of evolution did Charles Darwin observe among animals of the Galapagos Islands during his trip to this Archipelago?
Charles Darwin believed that all the life on Earth evolved (developed gradually) over millions of years from a few common ancestors.
Darwin's Theory of Evolution holds that variation within species occurs randomly and that the survival or extinction of each organism is determined by that organism's ability to adapt to its environment.
To illustrate this idea we can look at Galapagos finches evolution.
An ancestral Galapagos finch arrived millions of years ago, and because of the Galapagos Islands' isolation, their geological make-up, odd weather for tropical standards, and a chain of islands to hop around, it ended up into a set of different species that differentiate themselves not only in behavior, but most important, their overall diet, and thus their beaks.
When you need a specific tool for a specific use, you don't go around trying all the tools until you find the right one...over time, you rather develop a specific one. Simple.
It may sound Lamarckian, and from that angle it sure is. But here come Darwinian principles: variation acts as a regulating factor of the truly fit (something unheard of by Lamarck).
Slight variations in beak size design the evolutionary mechanism that allows species to be different. In other words, the species-making machine. Biological terms like allopatric and sympatric speciation complement this idea better.
It is said by some scientists that these observations made on Galapagos finches inspired Darwin in his theory on the Origin of Species and Natural Selection.
Colonization, competition, feeding grounds, isolation, ecological setup, nesting habitat, age and altitude of the Galapagos Islands are important aspects that have to be considered when understanding Darwins Finches.
In a world of stable populations where each individual must struggle to survive, those with the best characteristics will be more likely to survive, and those desirable traits will be passed to their offspring.
These advantageous characteristics are inherited by following generations, becoming dominant among the population through time. This is natural selection.
It may be further inferred that natural selection, if carried far enough, makes changes in a population, eventually leading to new species.
These observations have been amply demonstrated in biology, and even fossils demonstrate the veracity of these observations.
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