Augustin Pyramus de Candolle  Augustin Pyramus (or Pyrame) de Candolle (, , ; 4 February 17789 September 1841) was a Swiss botanist. René Louiche Desfontaines launched de Candolle's botanical career by recommending him at an herbarium. Within a couple of years de Candolle had established a new genus, and he went on to document hundreds of plant families and create a new natural plant classification system. Although de Candolle's main focus was botany, he also contributed to related fields such as phytogeography, agronomy, paleontology, medical botany, and economic botany. De Candolle originated the idea of "Nature's war", which influenced Charles Darwin and the principle of natural selection. de Candolle recognized that multiple species may develop similar characteristics that did not appear in a common evolutionary ancestor; a phenomenon now known as convergent evolution. During his work with plants, de Candolle noticed that plant leaf movements follow a near-24-hour cycle in constant light, suggesting that an internal biological clock exists. Though many scientists doubted de Candolle's findings, experiments over a century later demonstrated that ″the internal biological clock″ indeed exists. De Candolle's descendants continued his work on plant classification. Alphonse de Candolle and Casimir Pyrame de Candolle contributed to the "Prodromus Systematis Naturalis Regni Vegetabilis", a catalog of plants begun by Augustin Pyramus de Candolle. Augustin Pyramus de Candolle was born on 4 February 1778 in Geneva, Switzerland, to Augustin de Candolle, a former official, and his wife, Louise Eléonore Brière. His family descended from one of the ancient families of Provence in France, but relocated to Geneva at the end of the 16th century to escape religious persecution. At age seven de Candolle contracted of a severe case of hydrocephalus, which significantly affected his childhood. Nevertheless, he is said to have had great aptitude for learning, distinguishing himself in school with his rapid acquisition of knowledge in classical and general literature and his ability to write fine poetry. In 1794, he began his scientific studies at the Collège de Genève, where he studied under Jean Pierre Étienne Vaucher, who later inspired de Candolle to make botanical science the chief pursuit of his life.