Charles Darwin and the theory of evolution

Darwin's Theory of Evolution

galapagos charles darwinMany Scientists at the beginning of the 1800s suspected that some kind of evolution must have occurred to develop the living things around them. However, they had no unifying theory to explain how this evolution might have occurred. The two leading scientists of evolution were Jean Lamarck and Charles Darwin.

Charles Darwin (1809-1882) disliked school and preferred observing birds and collecting insects to study. He attended medical school in Scotland when he was only16. However he found medicine "intolerably dull." Darwin changed course to first study to be part of the clergy, and then later to the studies of natural history. In 1831 Darwin was chosen for the position of naturalist on the ship the HMS Beagle.

The Voyage of the Beagle

The Beagle was to make a five-year mapping and collecting expedition to South America and the South Pacific. As the ships naturalist, Darwin's job was to collect specimens, make observations and keep careful records of anything he observed. In Chile he observed the results of an earthquake where land had been lifted by several feet. In the Andes he observed fossil shells of marine organisms in rock beds at about 4,300 m in the Andes. He decided that that over millions of year’s earthquakes and other geologic processes could change the geology of the land, and once land had changed, new habitats would form. He also began to realise that animals would have had to adapt to these changes. To us now, this may all seem logical, but in the early 1830’s this was very revolutionary and against the principles of the church teachings.

During the Beagle's five-year trip the captain would often drop Darwin off at one port and pick him up months later at another. During his time on land Darwin trekked hundreds of miles through unmapped regions. He observed thousands of species of organisms and collected many different types of fossils. On the long sea voyages he used his time to catalog his specimens and write his notes.  A special part of this voyage was a time spent in Galapagos. During this time Darwin was to begin to form ideas that later would lead to revolutionary ideas… 

Darwin back in England, and the theory of Evolution

 

In October 1836 Darwin returned to England where his collection from the Beagle voyage was praised by the scientific community. Darwin sent many specimens to experts for study. One such expert, a ornithologist (bird specialist), studied Darwin's bird collections from the Galapagos Islands. He reported that Darwin had collected 13 similar but separate species of finches. Each finch species had a distinctive bill specialized for a particular food source. The similarities of the Galapagos finches led Darwin to theorize that the finches shared a common ancestor, but had adapted to the different environment of each island. For example, on some islands the fruits for birds to eat where very, very hard. So the finch would have to develop a different shaped beak to crack the nut open. If the finches on that island hadn’t developed the different shaped beak, they would not have survived and would have become extinct.  With this information and ideas, Darwin in 1837 began his first book on evolution, which was change the way the scientific world, and ordinary people, thought about the origins of the world and life.