Charles Darwin

English naturalist and geologist (1809–1882), born in Shrewsbury into a wealthy and intellectually distinguished family — his paternal grandfather, Erasmus Darwin, had already speculated on the evolution of species — initially trained in medicine at Edinburgh and then in theology at Cambridge before discovering his true vocation as a field naturalist. The voyage that would change his life and the history of biology was his participation, between 1831 and 1836, as naturalist aboard HMS Beagle, a surveying expedition that took him across South America, the Galápagos Islands and the Pacific Ocean, where he gathered an overwhelming quantity of geological and biological observations — particularly on the variations between related species from one island to another — that would sow the seed of his later theory. Back in England, Darwin took more than twenty years to publish his conclusions, meticulously refining them and gathering additional evidence, until receiving a manuscript from Alfred Russel Wallace independently setting out a very similar theory spurred him to accelerate publication. On the Origin of Species (1859) sets out the theory of evolution by natural selection: within a population, individuals vary; some of these variable traits make them better suited to survive and reproduce in their environment; these advantageous traits are passed on more frequently to offspring; and, across successive generations, this cumulative process explains both organisms' adaptation to their environment and the very origin of new species from common ancestors, without needing to appeal to any design or supernatural intervention. The theory, which placed the human species within the same evolutionary process as the rest of living beings — an implication Darwin developed explicitly in The Descent of Man (1871) — provoked immediate and lasting religious and scientific controversy, but ultimately became established as the unifying foundation of all modern biology, to the point that the geneticist Theodosius Dobzhansky would state a century later that 'nothing in biology makes sense except in the light of evolution'.

13 works

• A Biographical Sketch of an Infant
• Geological Observations on South America
• Insectivorous Plants
• Journal of Researches into the Natural History and Geology of the Countries Visi
• On the Origin of Species by Means of Natural Selection
• The Autobiography of Charles Darwin
• The Descent of Man, and Selection in Relation to Sex
• The Expression of the Emotions in Man and Animals
• The Foundations of the Origin of Species
• The Origin of Species by Means of Natural Selection
• The Power of Movement in Plants
• The Variation of Animals and Plants under Domestication
• The Voyage of the Beagle