Charles Darwin, an English scientist, wrote the book, "On the Origin of Species by Means of Natural Selection," which has served as the basis for modern theories concerning evolution since its publication in 1859. While evolutionists existed before his time, Darwin's theory of natural selection changed the way humans think about the natural world.
Darwin grew up in a wealthy family and began studying medicine at Edinburg, but found little in the field to motivate him. His father suggested he study to become a minister. Darwin moved to Cambridge to study divinity. At Cambridge, Darwin developed a friendship with John Stevens Henslow, a professor of botany. Through this friendship, Darwin gained passage on the HMS Beagle.
In 1835 the Beagle arrived at the Galapagos Islands. Darwin collected specimens of plants and birds. He also observed differences in the shells of sea turtles. These subtle variations caught Darwin's attention.
Once home, Darwin began writing about his observations. In 1858, Robert Wallace sent Darwin a letter revealing Wallace had also developed a theory of evolution based on natural selection. Darwin was forced to present his theory with Wallace by the revelation. While both naturalists had drawn similar conclusions, Darwin had collected evidence that supported his work.
Darwin died in 1882. He is buried in Westminster Abby. His observations and work continue to influence biology as well as other fields of science.