"History of Charles Darwin, a famous naturalist who was born on February 12, 1809 in Shrewsbury, England. Describe his scientific journey aboard the HMS Beagle in 1831, focusing on observations and discoveries in South America and the Galapagos Islands. Explain the evolution of his thinking and how his theory of natural selection , listed in the book 'On the Origin of Species' in 1859, formed the foundation of modern evolutionary biology."