Darwin's Theory of Evolution

Darwin's Theory of Evolution

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3-13-06
Darwin’s Theory of Evolution
Charles Darwin was a very intelligent thinker who studied natural history, and contributed much of what we know today with his theory. Darwin grew fascinated by his observations he collected while journeying the world on the H.M.S. Beagle. He realized there is an enormous number of different species of animal, and wondered why some of these animals didn’t live in separate locations like their own he visited. Darwin collected fossils when he stopped, and also thought why some of these animals were not alive to this day, and how some animals might be related to the fossils. The most influential stop Darwin made was at the Galapagos Islands. He encountered three types of tortoises, very alike and yet different. At the Islands with less vegetation the tortoises had extended necks, with a smaller shell of protection. The islands with more vegetation were home to tortoises with much shorter necks, but a larger shell. The islands that lay in between both these areas contained tortoises in the middle of these characteristics. The explanations for these unusual observations were very simple. The islands with more rainfall produced more vegetation, so the tortoise didn’t have to reach far for food. With more food around, more predators were more prominent, therefore explaining the larger shell. The islands with less rainfall produced less vegetation causing the tortoise to reach for its food more. With less food, predators died out; the tortoise has no real use for a large shell. Darwin also collected small birds he found searching for food. He observed the noticeable difference in the beak sizes and lengths of the various same birds. He explained this by saying each bird lived in a specialized place in its ecosystem. Each bird would eat food, which none or few other animals also ate, or otherwise it would compete for food. Some of the birds adapted by eating nectar from flowers, which in turn evolved their beaks into long,...