In 1831, at the age of 22, Darwin was invited to join HMS Beagle as the ship’s naturalist and companion to the captain. HMS Beagle was about to embark on a journey around the world. The purpose of the trip was to survey the coast of South America, which allowed Darwin much time to explore nearby lands. During the five year journey of HMS Beagle, Darwin filled dozens of notebooks with careful observations and collected thousands of specimens. Darwin later called the Beagle voyage “by far the most important event in my life.”
On the Origin of Species by Natural Selection was first published in 1859. It was written for scientists as well as members of the general public and sold out in bookstores on the first day. It eventually went through six editions and sold thousands of copies in Darwin’s lifetime.
Darwin returned from the Beagle voyage as a well-respected naturalist. He immediately began studying the specimens he had collected and discussing what he had seen with other prominent researchers of the time. Slowly the idea of evolution by means of natural selection took shape in his mind. Within a few years he had worked out the foundations of his ideas, but he did not publish them for more than 20 years out of concern about how they would be received by scientists, the general public, and the church. Instead, Darwin continued to do research and gather evidence to test his ideas.
In 1858 Darwin received a startling letter from naturalist Alfred Russel Wallace that laid out an idea that was remarkably similar to his own. This letter convinced Darwin that it was time to make his thoughts known. In 1858 colleagues read letters from Darwin and Wallace at a meeting of the Linnean Society of London. In 1959 Darwin published On the Origin of Species by Means of Natural Selection, in which he laid out what is now called the Theory of Evolution and the supporting evidence he had collected over the past several decades.
Darwin provided the world with a logical, understandable, and testable idea of how populations of organisms change over time. The idea has been tested for more than 150 years in every imaginable way from field studies to computer modeling, and with every imaginable organism. Each generation brings new tools and techniques to continue this testing, and each generation adds to the body of evidence in support of this robust theory. After more than 150 years, the accumulated support for evolution is overwhelming.
Darwin’s dynamic view of life rocked the world he lived in and the reverberations are still felt today. But as the famous geneticist Theodosius Dobzhansky observed in 1973, “Nothing in biology makes sense except in the light of evolution.”