During his time as the ship's naturalist aboard the Beagle from 1831-
1836, Charles Darwin had the opportunity to study the wildlife of the Galapagos
Islands. On the islands, he was amazed by the great diversity of life. Most
particularly, he took interest in the island's various finches, whose beaks were
all highly adapted to their particular lifestyles. He hypothesized that there
must be some process that lead to such diversity and adaptation, and he spent
much of his time trying to puzzle out just what the process might be. After
returning from his voyage (bringing with him numerous dead finches, killed and
stuffed at his behest), and at the urging of friends, Darwin put his thought in
writing in a 490-page "abstract" that he entitled On the Origin of
Species. He published the book in 1859.
The public reception of Origin was phenomenal. Within 15 years, it was
well accepted that evolution did occur the way Darwin said, slowly and in small
steps. However, the mechanism of natural selection remained difficult to accept
at the time because there were many points Darwin himself admittedly could not
explain. For example, he knew that traits were passed down from parents to
offspring, but he did not know how this happened. It was not until the early
1900's, when the field of genetics became the focus of
intense study that Darwin's mechanism of natural selection received more intense
scrutiny and deeper scientific support. With the discoveries of genetics,
Darwin's theories gained a scientific basis beyond observation and were
consequently accepted as a plausible mechanism for evolutionary change. Even
before genetics arrived on the scene, the idea of "survival of the fittest"
captured the imagination of the public. The idea was applied to everything from
the business world to the structure of society as a whole.