Augustin Pyramus de Candolle

A. P. de Candolle
A. P. de Candolle
Born	4 February 1778 Geneva, Switzerland
Died	9 September 1841(1841-09-09) (aged 63) Geneva, Switzerland
Nationality	Switzerland
Fields	Botany, Agronomy, Phytogeography
Known for	System of Taxonomy, Principle of "Nature's War"
Notable awards	Royal Medal (1833)
Author abbreviation (botany)	DC.

Augustin Pyramus de Candolle also spelled Augustin Pyrame de Candolle (4 February 1778 – 9 September 1841) was a Swiss botanist. René Louiche Desfontaines launched Candolle's botanical career by recommending him at an herbarium. Within a couple of years 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 Candolle's main focus was botany, he also contributed to related fields such as phytogeography, agronomy, paleontology, medical botany, and economic botany.

Candolle originated the idea of "Nature's war", which influenced Charles Darwin and the principle of natural selection.^[1] Candolle recognized that multiple species may develop similar characteristics that did not appear in a common evolutionary ancestor; this was later termed homology. During his work with plants, 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 Candolle's findings, experiments over a century later demonstrated that the internal biological clock indeed exists.

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.

Early life

Augustin Pyramus de Candolle was born on February 4, 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.^[2]

At age seven Candolle contracted of a severe case of hydrocephalus, which significantly affected his childhood.^[3] 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.^[2] In 1794, he began his scientific studies at the Collège Calvin, where he studied under Jean Pierre Étienne Vaucher, who later inspired Candolle to make botanical science the chief pursuit of his life.^[2]

Career in botany

In 1796, Candolle moved to Paris after receiving an invitation from French geologist Déodat Gratet de Dolomieu.^[4] His botanical career began with the help of René Louiche Desfontaines, who recommended Candolle for work in the herbarium of Charles Louis L'Héritier de Brutelle during the summer of 1798.^[4] The position elevated Candolle's reputation and also led to valuable instruction from Desfontaines himself.^[4] Candolle established his first genus, Senebiera, in 1799.^[4]

Candolle's first productions, Plantarum historia succulentarum (4 vols., 1799) and Astragalogia (1802), brought him to the notice of Georges Cuvier and Jean-Baptiste Lamarck. Candolle, with Cuvier's approval, acted as deputy at the Collège de France in 1802. Lamarck entrusted him with the publication of the third edition of the Flore française (1803–1815).^[2] In the introduction to this work, Principes élémentaires de botanique, Candolle proposed a natural method of plant classification as opposed to the artificial Linnaean^[5] method.^[2] The premise of Candolle's method is that taxa do not fall along a linear scale; they are discrete, not continuous.^[6]

In 1804, Candolle published his Essai sur les propriétés médicales des plantes and was granted a doctor of medicine degree by the medical faculty of Paris.^[2] Two years later, he published Synopsis plantarum in flora Gallica descriptarum.^[2] Candolle then spent the next six summers making a botanical and agricultural survey of France at the request of the French government, which was published in 1813.^[2] In 1807 he was appointed professor of botany in the medical faculty of the University of Montpellier, where he would later become the first chair of botany in 1810.^[2] While in Montpellier, Candolle published his Théorie élémentaire de la botanique (Elementary Theory of Botany, 1813),^[2] which introduced a new classification system and the word taxonomy.^[7] Candolle moved back to Geneva in 1816 and in the following year was invited by the government of the Canton of Geneva to fill the newly created chair of natural history.^[2]

Candolle spent the rest of his life in an attempt to elaborate and complete his natural system of botanical classification.^[2] Candolle published initial work in his Regni vegetabillis systema naturale, but after two volumes he realized he could not complete the project on such a large scale.^[2] Consequently, he began his less extensive Prodromus Systematis Naturalis Regni Vegetabilis in 1824. However, he was only able to finish only seven volumes, or two-thirds of the whole.^[2] Even so, he was able to characterize over one hundred families of plants, helping to lay the empirical basis of general botany.^[8] Although Candolle's main focus was botany, throughout his career he also dabbled in fields related to botany, such as phytogeography, agronomy, paleontology, medical botany, and economic botany.^[9]

Later life

Augustin de Candolle was the first of four generations of botanists in the Candolle dynasty.^[10] His son, Alphonse de Candolle, whom he fathered with his wife, Mademoiselle Torras, eventually succeeded to his father's chair in botany and continued the Prodromus.^[2] Casimir Pyrame de Candolle, Augustin de Candolle's grandson, also contributed to the Prodromus through his detailed, extensive research and characterization of the Piperaceae family of plants.^[11] Augustin de Candolle's great-grandson, Richard Emile Augustin de Candolle, was also a botanist.^[12]

Augustin de Candolle died on 9 September 1841 in Geneva, after being sick for many years.^[2]

Legacy

He is remembered in the genera Candollea and Candolleodendron, both plants.^[13]

Candollea, a scientific journal that publishes papers on systematic botany and phylotaxonomy,^[14] was named after Candolle and his descendants in honor of their contribution to the field of botany.^[11]

Classification system

Candolle was the first to put forward the idea of "Nature's war",^[1] writing of plants being "at war one with another" with the meaning of different species fighting each other for space and resources.^[15] Charles Darwin studied de Candolle's "natural system" of classification in 1826 when at the University of Edinburgh,^[16] and in the inception of Darwin's theory in 1838 he considered "the warring of the species", adding that it was even more strongly conveyed by Thomas Malthus, producing the pressures that Darwin later called natural selection.^[15] In 1839 de Candolle visited Britain and Darwin invited him to dinner, allowing the two scientists the opportunity to discuss the idea.^[1]

Candolle was also among the first to recognize the difference between the morphological and physiological characteristics of organs. He ascribed plant morphology as being related to the number of organs and their positions relative to each other rather than to their various physiological properties. Consequently, this made him the first to attempt to attribute specific reasons for structural and numerical relationships amongst organs, and thus to distinguish between major and minor aspects of plant symmetry.^[8] To account for modifications of symmetry in parts of different plants, an occurrence that could hinder the discovery of an evolutionary relationship, de Candolle introduced the concept of homology.^[17]

Chronobiology

Candolle also made contributions to the field of chronobiology. Building upon earlier work on plant circadian leaf movements contributed by such scientists as Jean-Jacques d'Ortous de Mairan and Henri-Louis Duhamel du Monceau, Candolle observed in 1832 that the plant Mimosa pudica had a free-running period of leaf opening and closing of approximately 22–23 hours in constant light, significantly less than the approximate 24-hour period of the Earth's light-dark cycles.^[18][19] Since the period was shorter than 24 hours, he hypothesized that a different clock had to be responsible for the rhythm; the shortened period was not entrained—coordinated—by environmental cues, thus the clock appeared to be endogenous.^[20] Despite these findings, a number of scientists continued to search for "factor X", an unknown exogenous factor associated with the earth's rotation that was driving circadian oscillations in the absence of a light dark schedule, until the mid twentieth century.^[21] In the mid 1920's, Erwin Bunning repeated Candolle's findings and came to similar conclusions, and studies that showed the persistence of circadian rhythm in the South Pole and in a space lab further confirmed the existence of oscillations in the absence of environmental cues.^[21] In 1926, Maynard Johnson provided the first demonstration of the endogenous nature of circadian rhythms in mammals from rhythms observed in mice.^[22] However, the location of this endogenous clock and its method of operation remained unknown for another 100 years after Candolle's findings. Confirmation of an internal pacemaker arrived in 1972 when Robert Moore and Irving Zucker both independently localized the suprachiasmatic nucleus as the endogenous oscillator in rats through lesion experiments.^[23][24]

The standard author abbreviation DC. is used to indicate this individual as the author when citing a botanical name.^[25]

Notes

1. ^ ^{a b c} Desmond & Moore 1991, p. 283.
2. ^ ^{a b c d e f g h i j k l m n o p} Chisholm 1911.
3. ^ Brewster et al. 1842, p. 253.
4. ^ ^{a b c d} Gray & Sargent 1889, pp. 292–293.
5. ^ Waggoner 2000.
6. ^ Stevens 1994, p. 79.
7. ^ Singh 2004, p. 20.
8. ^ ^{a b} Sachs, Balfour & Garsney 1890, pp. 127–128.
9. ^ Emerson 1842, pp. 225–226.
10. ^ Trelease 1924, p. 55.
11. ^ ^{a b} Trelease 1924, p. 60.
12. ^ Trelease 1924, p. 61.
13. ^ Isely 2002, p. 147.
14. ^ Conservatoire et Jardin botaniques.
15. ^ ^{a b} Desmond & Moore 1991, p. 265.
16. ^ Desmond & Moore 1991, p. 43.
17. ^ Allaby 2010, p. 87.
18. ^ McClung 2006.
19. ^ Eckardt 2005.
20. ^ Moore-Ede 1986, pp. R741–R742.
21. ^ ^{a b} Albrecht 2010, pp. 3–4.
22. ^ Refinetti 2006, pp. 5–8.
23. ^ Moore & Eichler 1972.
24. ^ Stephan & Zucker 1972.
25. ^ International Plant Names Index 2009.

References

• Albrecht, Urs (2010). The Circadian Clock. Springer New York. doi:10.1007/978-1-4419-1262-6_1. ISBN 9781441912626. 
• Allaby, Michael (2010). Plants: Food, Medicine, and the Green Earth. Infobase Publishing. ISBN 0816061025. 
• Brewster, David; Taylor, Richard; Phillips, Richard; Kane, Robert (March 1842). "Proceedings of Learned Societies: Royal Society Obituary Notice". Philosophical Magazine and Journal of Science 20. http://books.google.com/books?id=7XiUObxbsYQC&pg=PA253. 
• "Candolle, Augustin Pyramus de (1778–1841)". International Plant Names Index. 7 January 2009. http://www.ipni.org/ipni/idAuthorSearch.do?id=16855-1. Retrieved 6 May 2011. 
• "Candollea". Conservatoire et Jardin botaniques. Ville de Genève. http://www.ville-ge.ch/cjb/publications_candollea.php. Retrieved 6 May 2011. 
•  Chisholm, Hugh, ed (1911). "Candolle, Augustin Pyrame De". Encyclopædia Britannica (11th ed.). Cambridge University Press. http://www.gutenberg.org/files/33052/33052-h/33052-h.htm#ar78. 
• Desmond, Adrian; Moore, James (1991). Darwin. London: Michael Joseph, Penguin Group. ISBN 0718134303. 
• Eckardt, Nancy A. (2005). "Temperature Entrainment of the Arabidopsis Circadian Clock". The Plant Cell 17 (3): 645–647. doi:10.1105/tpc.104.031336. 
• Emerson, George B (1842). "A Notice of Prof. Augustine Pyrame De Candolle". The American journal of science and arts 42: 217–226. http://books.google.com/books?id=3TYPAAAAYAAJ&pg=PA217#v=onepage&q&f=false. Retrieved 16 May 2011. 
• Gray, Asa; Sargent, Charles (1889). Scientific papers of Asa Gray: Selected by Charles Sprague Sargent. Houghton Mifflin. http://books.google.com/books?id=_48KAAAAMAAJ&pg=PA292. Retrieved 15 May 2011. 
• Isely, Duane (2002). One Hundred and One Botanists. Purdue University Press. ISBN 9781557532831. http://books.google.com/books?id=an6r8m0JfV8C&pg=PA147. Retrieved 13 April 2011. 
• McClung, C. Robertson (2006). "Plant Circadian Rhythms". The Plant Cell 18 (4): 792–794. doi:10.1105/tpc.106.040980. PMC 1425852. PMID 16595397. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1425852. 
• Moore, Robert; Eichler, Victor (July 1972). "Loss of a circadian adrenal corticosterone rhythm following suprachiasmatic lesions in the rat". Brain Research 42 (1): 201–206. doi:10.1016/0006-8993(72)90054-6. PMID 5047187. 
• Moore-Ede, MC. (1986). "Physiology of the circadian timing system: predictive versus reactive homeostasis". American Journal of Physiology - Regulatory, Integrative and Comparative Physiology 250 (5): R737–R752. PMID 3706563. 
• Refinetti, Robert (2006). Circadian Physiology, Second Edition. CRC Press. ISBN 9780849322334. 
• Sachs, Julius; Balfour, Isaac Bayley; Garsney, Henry Edward Fowler (1890). History of Botany (1530–1860). Oxford: Clarendon Press. http://en.wikisource.org/wiki/History_of_botany_%281530%E2%80%931860%29/Book_1/Chapter_3#126. Retrieved 6 May 2011. 
• Singh, Gurcharan (2004). Plant systematics: an integrated approach. Science Publishers. ISBN 9781578083510. http://books.google.com/books?id=In_Lv8iMt24C&pg=PA20. Retrieved 13 April 2011. 
• Stephan, Friedrich K; Zucker, Irving (1972). "Circadian Rhythms in Drinking Behavior and Locomotor Activity of Rats Are Eliminated by Hypothalamic Lesions". Proceedings of the National Academy of Sciences of the United States of America 69 (6): 1583–1586. doi:10.1073/pnas.69.6.1583. PMC 426753. PMID 4556464. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=426753. 
• Stevens, Peter Francis (1994). The development of biological systematics: Antoine-Laurent de Jussieu, nature, and the natural system. Columbia University Press. ISBN 9780231064408. http://books.google.com/books?id=kh9HXVALm9oC&pg=PA79. Retrieved 13 April 2011. 
• Trelease, William (July 1924). "Four Generations of Memorable Botanists". The Scientific Monthly 19 (1). JSTOR 7220. 
• Waggoner, Ben (7 July 2000). "Carl Linnaeus (1707–1778)". University of California Museum of Paleontology. University of California. http://www.ucmp.berkeley.edu/history/linnaeus.html. Retrieved 6 May 2011. "Linnaeus freely admitted that this produced an "artificial classification", not a natural one, which would take into account all the similarities and differences between organisms." 

External links

• Plantarum historia succulentarum, online
• Les liliacées, online
• Biography
• View digitized titles by and a short biography of Candolle in Botanicus.org
• Malpighiaceae/Candolle
• Candolle Timeline of Important Events
• Prodromus systematis naturalis regni vegetabilis

Persondata
Name	Candolle, A. P. de
Alternative names
Short description
Date of birth	4 February 1778
Place of birth	Geneva, Switzerland
Date of death	9 September 1841
Place of death	Geneva, Switzerland