Charles Darwin was an English naturalist, geologist, and biologist who is best known for his contributions to the science of evolution. He is most famously associated with the HMS BEAGLE, a British Royal Navy survey ship on which he served as a naturalist during its five-year voyage around the world from 1831 to 1836. During this voyage, Darwin collected specimens and made observations that would later form the basis of his theory of evolution by natural selection. He also studied the geology of South America and the Galapagos Islands, where he observed the diversity of species and the similarities between them. Darwin's work on evolution was published in 1859 in his book On the Origin of Species. He also wrote about the concept of sexual selection, which he proposed in The Descent of Man and Selection in Relation to Sex. Darwin's other works include The Expression of the Emotions in Man and Animals and The Formation of Vegetable Mould Through the Action of Worms. Darwin's ideas have had a profound impact on the scientific community and continue to shape our understanding of the natural world.