Léon Camille Marius Croizat

Léon Croizat

Léon Camille Marius Croizat (born July 16, 1894 in Turin , † November 10, 1982 in Coro ) was a Franco-Italian botanist who worked in Venezuela and developed panbiogeography as a hypothesis that the evolution of living things over large areas and long periods of time should explain away. Its official botanical author's abbreviation is " Croizat ".

Life

Léon Croizat was born in Turin to French parents. There he studied law as a bread-and-butter profession without ever denying his inclination to natural history. After graduating, he devoted himself to botany and zoology . He developed trains of thought which, contrary to the Darwinism of his time , led him to hypotheses about the development of life over the earth's surface over long periods of time. During the First World War, he served in the Italian army from 1914 to 1919. In 1923 he emigrated to New York with his wife and two children. In order to earn money in addition to day labor, he painted watercolors that were exhibited in the Brooklyn Museum of Art . After the stock market crash of 1929/1930, the art market collapsed and Croizat moved to Paris, where he stayed with his family until 1936. Between 1936 and 1946 he lived in the USA , where he worked as a research assistant to Elmer Drew Merrill (1876-1956) at the Arnold Arboretum at Harvard University . Since he spoke French, Italian, Spanish, Portuguese, Latin, Russian, German and, with the help of a dictionary, Greek, he was soon able to familiarize himself with the intricacies of the Euphorbiaceae in the herbarium .

Croizat was invited to Venezuela in 1947 by the Swiss botanist Henri Pittier (1857–1950). He accepted a position in the Faculty of Agriculture at the University of Venezuela. In 1951 he was appointed full professor of botany and ecology at the Universidad de Los Andes, Venezuela.

From 1951 to 1952 he took part as a botanist in the Franco-Venezuelan expedition led by José Maria Cruxent, which looked for the sources of the Orinoco in the footsteps of Alexander von Humboldt . During this time he divorced his first wife in order to be able to marry Catalina, a child psychologist who had immigrated from Hungary . After completing her second degree in landscape architecture, Catalina gave him the financial freedom to give up all official academic positions in 1953 and to devote himself exclusively to the biological problems that interest him.

In 1959/1960 he undertook an expedition through South America , 1962/1963 he visited Europe, where he gave lectures at the Linnean Society in London and at the Muséum national d'histoire naturelle in Paris . He lived in Caracas with his wife until 1975 . Then he and her took over the management of the "Jardin Botanico Xerofito" in Coro , a city about 400 kilometers west of Caracas. There the two began in 1970 with the establishment and development of a botanical garden. After his death, the garden was named "Jardin Xerofito Dr. Leon Croizat" in his honor. Catalina Croizat remained director until her death in 1997.

Léon Croizat died of a heart attack on November 30, 1982 in Coro. He was able to publish seven books and around 300 scientific articles, altogether over 15,000 printed pages, during his lifetime.

Honors

Croizat received the Henri Pittier Order of Merit for Conservation from the Venezuelan state. The Italian state honored him with its Order of Merit. The genus Croizatia Steyerm was named after him . from the family of the Phyllanthaceae . Numerous plant and animal species from South America were named in his honor.

Panbiogeography

The panbiogeography method developed by Léon Croizat is based on a cartographic process in which the current distribution of a taxon or several taxa is plotted on a world map and any disjunctions , i.e. interruptions in a distribution area, are outlined with lines. According to Croizat's hypothesis, the resulting pattern represents the potential or former range of a taxon.

In order to explain interruptions in the currently visible range, Croizat postulated that common ancestors of taxa must have been more common in earlier geological periods. Extinction events in later periods then led to an incomplete distribution area. Croizat viewed the evolution of organisms as essentially determined by time, space and form. Of these three factors, space is the one that biogeography addresses most closely.

Scientific recognition

Croizat's hypotheses are still controversial today. While recent scientists who attribute a major role to active or passive distribution of a taxon reject Croizat's approach, others consider him one of the most original thinkers in modern comparative biology . He laid the foundation for an interdisciplinary consideration of organismic distribution patterns between biology and geography .

Fonts (selection)

• Manual of Phytogeography or An Account of Plant Dispersal Throughout the World . Junk, The Hague 1952.
• Panbiogeography or An Introductory Synthesis of Zoogeography, Phytogeography, Geology; with notes on evolution, systematics, ecology, anthropology, etc. Caracas 1958.
• Principia Botanica or Beginnings of Botany . Caracas 1961.
• Space, Time, Form: The Biological Synthesis . Caracas 1964.
• Vicariance / vicariism, panbiogeography, "vicariance biogeography," etc .: a clarification. In: Systematic Zoology. Volume 31, 1982, pp. 291-304.

literature

• RC Craw, JR Grehan, MJ Heads: Panbiogeography: Tracking the History of Life. Oxford University Press, New York 1999, ISBN 0-19-507441-6 .
• J. Llorente, J. Morrone, A. Bueno, R. Perez-Hernandez, A. Viloria, D. Espinosa: Historia del desarrollo y la recepcion de las ideas panbiogeograficas de Leon Croizat. In: Revista de la Academia Colombiana de Ciencias Exactas, Fisicas y Naturales. Volume 24, No. 93, 2000, pp. 549-577.
• JJ Morrone: Entre el Escarnio y el Encomio: Léon Croizat y la Panbiogeografía. In: Interciencia. Volume 25, No. 1, 2000, pp. 41-47.
• JJ Morrone: Homología Biogeográfica: las Coordenadas Espaciales de la Vida. (= Cuadernos del Instituto de Biología, México. DF 37). Instituto de Biología, UNAM 2004, ISBN 970-32-1640-4 .
• JJ Morrone: La Vita tra lo Spazio e il Tempo. Il Retaggio di Croizat e la Nuova Biogeografia. Medical Books, Palermo 2006, ISBN 88-8034-021-2 .

Individual evidence

1. ↑ nzetc.org Never A Serious Scientist: The Life of Leon Croizat
2. ↑ Jardin Botanico Xerofito ( Memento of July 3, 2010 in the Internet Archive )
3. ↑ Jardin Xerofito Dr. Leon Croizat ( Memento from October 26, 2010 in the Internet Archive )
4. ↑ Lotte Burkhardt: Directory of eponymous plant names . Extended Edition. Botanic Garden and Botanical Museum Berlin, Free University Berlin, Berlin 2018. (bgbm.org)
5. ^ ^{A b} R. C. Craw, JR Grehan, MJ Heads: Panbiogeography: Tracking the History of Life. Oxford University Press, New York 1999.
6. ^ L. Croizat: Space, Time, Form: The Biological Synthesis. Self-published, Caracas 1964, p. 676.
7. ^ RDM Page: Graphs and generalized tracks: quantifying Croizat's panbiogeography. In: Systematic Zoology. Volume 36, 1987, pp. 1-17.
8. ↑ C. Colacino: Leon Croizat's biogeography and macroevolution, or ... "out of nothing, nothing comes". In: Philippine Scientist. Volume 34, 1997, pp. 73-88.
9. ↑ M. Heads, R. Craw: Bibliography of the scientific work of Leon Croizat, 1932–1982. In: Tuatara. Volume 27, 1984, pp. 67-75, (online)

Web links

• Author entry and list of the plant names described for Léon Camille Marius Croizat at the IPNI