Charles Darwin (1809–82) set sail on the Beagle in 1831, a half-hearted believer that species were unchanging. Molded by the science of his time, he believed the earth was eons old, species appeared in their current locations at an unknown time, and the Bible had nothing relevant to say about science. Eager for acceptance by the scientific establishment, the 23-year-old wanted to make his mark. But as radical new ideas began brewing in his head, he grew fearful about the threat to his reputation.