Darwin, an English biologist known for his theory of evolution, was born at Shrewsbury, England, on February 12, 1809. He was born on the same day and the same year as Abraham Lincoln, a coincidence that may alert American readers to Darwin's era. He studied, traveled, and published his famous On the Origin of Species (1859) just prior to the American Civil War.

Darwin's father was an affluent physician and his mother the daughter of the potter Josiah Wedgwood. Charles married Emma Wedgwood, his first cousin, in 1839. Due to his family's wealth, Darwin was made singularly free to pursue his interest in science.

Darwin entered Edinburgh to study medicine, but, as he described in his autobiography, lectures were "intolerably dull," human anatomy "disgusted" him, and he experienced "nausea" in seeing surgery. He subsequently entered Christ's College, Cambridge, to prepare for Holy...