When Darwin was in South America, he made several important discoveries about geology, coral reefs, and volcanoes. Finding fossils made his mind race with questions about life and explanations for it. In his journal he wrote, “Where on the face of the earth can we find a spot, on which close investigation will not discover signs of that endless cycle of change, to which this earth has been, is, and will be subjected?”
All this research and field work came together years later as he studied his notes, specimens, and journal entries. He no longer thought of life as different lines of ancestry, but as a single tree, branching and re-branching. That way, characteristics shared by different living things could be explained by their shared ancestry. He realized that if reproduction went unchecked, and grew geometrically, then the world would be overpopulated in a few hundred generations.
That has not happened so he thought that a large number of living things must be destroyed before they can reproduce. This came to be called, “natural selection.” Charles Darwin changed the way people look at living things.
Darwin’s Theory of Evolution by Natural Selection ties together all of the life sciences and explains where living things came from and how they adapt. In life, there is heredity, selection, and variation. Only certain members of a species reproduce, by natural selection, and pass along their characteristics. Variation deals with the environment and adaptation to it.
Charles Darwin was born in Shrewsbury, England in 1809. At 16 he studied medicine at Edinburgh University. He found out that surgery was not his calling and started studying to be a clergyman at Christ College, Cambridge. He obtained his degree in Theology in 1831.
In August, he signed on as a naturalist aboard the HMS Beagle and served for five years. It was his research during that voyage that formed the basis of his work on the Origin of Species by Means of Natural Selection.
He examined all the areas he visited, including South America, the Galapagos Islands, and islands in the Pacific Ocean and made detailed records of his observations.
The work that influenced him the most was Sir Charles Lyell's Principles of Geology. Lyell explained a new way of looking at nature. He showed that small changes, over time, can cause large changes. He felt that natural and observable causes should be used to explain things that happen in nature.
Darwin was able to observe many of these natural phenomenons, like earthquakes, erosion, volcanoes, and such. He came to believe that Lyell was right. Darwin returned to England in 1836. In 1839, he married Emma Wedgwood and was elected a Fellow of the Royal Society.
Charles Darwin was a kind and pleasant man, and suffered from intestinal illness and chronic fatigue all his life, possibly from Chagas Disease which he contracted while in South America. He died in April of 1882 and is buried in Westminster Abbey.