G. Ledyard Stebbins

George Ledyard Stebbins, Jr. (January 6, 1906 — January 19, 2000) was an American botanist and geneticist who is widely regarded as one of the leading evolutionary biologists and botanists of the 20th century.^[1] Stebbins received his PhD in botany from Harvard University in 1931. He went on to the University of California, Berkeley where his work with E. B. Babcock on the genetic evolution of species and his association with a group of evolutionary biologists known as the Bay Area Biosystematists, which included Theodosius Dobzhansky, led him to develop a comprehensive synthesis of plant evolution. His most important publication in this regard was Variation and Evolution in Plants (1950), which combined genetics and Darwin's theory of natural selection, and is considered to be a major contribution to modern evolutionary synthesis. Image File history File links Stebbins. ... Image File history File links Stebbins. ... January 6 is the 6th day of the year in the Gregorian calendar. ... 1906 (MCMVI) was a common year starting on Monday (see link for calendar). ... January 19 is the 19th day of the year in the Gregorian calendar. ... This article is about the year 2000. ... PhD usually refers to the academic title Doctor of Philosophy PhD can also refer to the manga Phantasy Degree This is a disambiguation page — a list of pages that otherwise might share the same title. ... Harvard University is a private university in Cambridge, Massachusetts, USA and a member of the Ivy League. ... University of California, Berkeley The University of California, Berkeley (also known as California, Cal, UCB, UC Berkeley, The University of California, or simply Berkeley) is a public, coeducational university situated east of the San Francisco Bay in Berkeley, California, overlooking the Golden Gate. ... Ernest Brown Babcock (July 10, 1877 - December 8, 1954) was an United States plant geneticist. ... In biology, a species is the basic unit of biodiversity. ... The Bay Area Biosystematists is a group of biologists, geneticists, paleontologists, and systematists that are also interested in evolution. ... Theodosius Grigorevich Dobzhansky (Russian — Феодосий Григорьевич Добржанский; sometimes anglicized to Theodore Dobzhansky; January 25, 1900 - December 18, 1975) was a noted geneticist and evolutionary biologist. ... Variation and Evolution in Plants is a book written by G. Ledyard Stebbins. ... Genetics (from the Greek genno γεννώ= give birth) is the science of genes, heredity, and the variation of organisms. ... In his lifetime Charles Darwin gained international fame as an influential scientist examining controversial topics. ... Natural selection is the metaphor Charles Darwin used in 1859 to name the process he postulated to drive the adaptation of organisms to their environments and the origin of new species. ... The modern evolutionary synthesis (often referred to simply as the modern synthesis or the evolutionary synthesis), neo-Darwinian synthesis or neo-Darwinism, generally denotes the combination of Charles Darwins theory of the evolution of species by natural selection, Gregor Mendels theory of genetics as the basis for biological...

From 1950, Stebbins was instrumental in the establishment of the Department of Genetics at the University of California, Davis. He was active in numerous organizations involved in the promotion of evolution, and science more generally, and was elected to the National Academy of Science. He was involved in the development of evolution-based science programs for Californian high schools, and the conservation of rare plants in that state. The University of California, Davis, commonly known as UC Davis, is one of the ten University of California campuses. ... President Harding and the National Academy of Sciences at the White House, Washington, DC, April 1921 The National Academy of Sciences (NAS) is a corporation in the United States whose members serve pro bono as advisers to the nation on science, engineering, and medicine. ...

Early life and education

Stebbins was born in Lawrence, New York, the youngest of three children. His parents were George Ledyard Stebbins, a wealthy real estate financier who developed Seal Harbor, Maine and helped to establish Acadia National Park, and Edith Alden Candler Stebbins; both parents were both born in New York and Episcopalians. Stebbins was known throughout his life as Ledyard, to distinguish himself from his father. The family encouraged their sons’ interest in natural history during their periodic journeys to Seal Harbor. In 1914, Edith contracted tuberculosis and the Stebbins moved to Santa Barbara, California to improve her health. Stebbins was enrolled at the Cate School in Carpinteria, California, where he was an average student. Lawrence is the name of some places in the U.S. state of New York: Lawrence, Nassau County, New York Lawrence, St. ... Acadia National Park preserves much of Mount Desert Island, and associated smaller islands, off the Atlantic coast of Maine. ... The Cathedral Church of Saint Peter and Saint Paul in Washington DC is the National Cathedral of the Episcopal Church in the United States of America. ... Mission Santa Barbara, known as the queen of the missions. Santa Barbara is a city in California, United States. ...

After graduating from high school, Stebbins embarked on a major in political studies at Harvard, in preparation for acareer in law, in the footsteps of his elder brother, Henry. By the third year of his undergraduate study, he decided to major in botany, despite his parents disapproval. He started graduate studies at Harvard in 1928, initially working on flowering plant taxonomy and biogeography—particularly that of the flora of New England—with Merritt Lyndon Fernald. He competed his MA in 1929 and continued to work toward his PhD. Stebbins became interested in using chromosomes for taxonomic studies, a method that Fernald did not support. Stebbins chose to concentrate his doctoral work on the cytology of plant reproductive processes, in the genus Antennaria, with cytologist E. C. Jeffrey as his supervisor and Fernald on his supervisory panel. During his PhD candidature, Stebbins sought advice and supervision from geneticist Karl Sax. Sax identified several errors in Stebbins work and disapproved Stebbins interpretation of results which while in accordance with Jeffery's views, were inconsistent with the work of contemporary geneticists. Jeffrey and Sax argued over Stebbins's dissertation, and the thesis was revised numerous times to accommodate their differing views. Harvard University is a private university in Cambridge, Massachusetts, USA, and a member of the Ivy League. ... Botany is the scientific study of plant life. ... Merritt Lyndon Fernald (October 5, 1873 - September 22, 1950) was an American botanist. ... Cell biology (also called cellular biology or cytology, from the Greek kytos, container) is an academic discipline which studies cells. ... Species See text The pussytoes is a genus Antennaria in the family Asteraceae. ... Edward Charles Jeffrey (May 21, 1866 - April 19, 1952) was a Canadian-American botanist who woked on vascular plant anatomy and phylogeny. ... Karl Sax (November 2, 1892 - October 8, 1973) was an American botanist and geneticist, in paricular he was noted for his research in cytogenetics and the effect of raditaion on chromosomes. ...

Stebbins's PhD was granted by Harvard in 1931. In March that year, Stebbins had married Margaret Chamberlin; together, they would have three children. In 1932 Stebbins took a teaching position in biology at Colgate University. Despite a busy teaching schedule, he managed some research work on cytogenetics. He continued to study the genetics of Antennaria and the behaviour of chromosomes in the hybrid peonies bred by biologist Percy Saunders. Saunders and Stebbins attended the 1932 International Congress of Genetics in Ithaca, New York. Here, Stebbins's interest was captured by talks by Thomas Hunt Morgan and Barbara McClintock, who spoke about chromosomal crossover. Stebbins repeated McClintock's crossover experiments in the peony, published several papers on the cytogenetics of Paeonia, and established his reputation as a geneticist. Colgate in mid-August, towards the end of Summer. ... Species See text The peony (Paeonia) is the sole genus in the flowering plant family Paeoniaceae. ... Thomas Hunt Morgan Thomas Hunt Morgan (September 25, 1866 — December 4, 1945) was an American geneticist. ... Barbara McClintock Barbara McClintock (June 16, 1902 – September 2, 1992) was a pioneering American scientist and one of the worlds most distinguished cytogeneticists. ... Chromosomal crossover is the process by which two chromosomes, paired up during prophase I of meiosis, exchange some distal portion of their DNA. Crossover occurs when two chromosomes, normally two homologous instances of the same chromosome, break and then reconnect but to the different end piece. ...

UC Berkeley

In 1935, Stebbins was offered a genetics research position at the University of California, Berkeley working with geneticist E. B. Babcock. Babcock needed assistance with large Rockefeller-funded project characterizing the genetics and evolutionary processes of plants from the genus Crepis. Babcock was interested in developing Crepis into a model plant, to enable genetic investigations similar to those possible in the model insect Drosophila melanogaster. Like the genera that Stebbins had previously studied, Crepis commonly hybridized, displayed polyploidy (chromosome doubling) and could make seed without fertilization (a process known as apomixis). Babcock and Stebbins had a productive collaboration, producing numerous papers and two monographs. The first was on the reclassification of the Asiatic Crepis species into the genus Youngia (1937). The second, The American Species of Crepis: their interrelationships and distribution as affected by polyploidy and apomixis (1938), was described by Swedish botanist Åke Gustafsson as the most important work on the formation of species during that period.^[2] University of California, Berkeley The University of California, Berkeley (also known as California, Cal, UCB, UC Berkeley, The University of California, or simply Berkeley) is a public, coeducational university situated east of the San Francisco Bay in Berkeley, California, overlooking the Golden Gate. ... Ernest Brown Babcock (July 10, 1877 - December 8, 1954) was an United States plant geneticist. ... Hawksbeard is a genus of about 200 annual and perennial flowering plants found in the family Asterales resembling Dandelion, the main differences being that Hawksbeards have multiple flowers per plant as well as branching stems. ... A model organism is a species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the model organism will provide insight into the workings of other organisms. ... Binomial name Drosophila melanogaster Meigen, 1830 dorsal view Drosophila melanogaster Meigen , 1830 (Black-bellied Dew-lover) a dipteran (two-winged) insect, is the species of fruit fly that is commonly used in genetic experiments; it is among the most important model organisms. ... Polyploid (in Greek: πολλαπλόν - multiple) cells or organisms that contain more than two copies of each of their chromosomes. ... In botany, apomixis is biological reproduction without fertilization, meiosis or production of gametes, with the result that the seeds are genetically identical to the parent plant. ... Youngia is an Asiatic genus of Asteraceae. ... Karl Ã…ke Torsten Gustafsson (1908-1988) was a Swedish botanist, geneticist and writer. ...

In the Crepis monograph, Babcock and Stebbins described the polyploid complex and its role in plant evolution. Some genera, such as Crepis, have a complex of reproductive forms that center on sexual diploids that have also given rise to polyploids; sometimes, as in Crepis, these are apomictic polyploids. Apomictic polyploids are able to perpetuate unbalanced polyploid types, such as triploids and pentatetraploids, which would be sterile if they had to sexually reproduce. Babcock and Stebbins also observed that polyploid types always have a wider distribution than diploid species, and proposed that polyploids have a greater potential to exploit varied environments, because they inherit all traits from both parents. Their observations offered insight into species formation and knowledge of how all these complex processes could provide information on the history of a genus. Stebbins's review "Types of polyploids: their classification and significance" published in American Naturalist in 1940, synthesized the literature on polyploidy and is considered a classic in the field. In biology, phylogenetics (Greek: phylon = tribe, race and genetikos = relative to birth, from genesis = birth) is the study of evolutionary relatedness among various groups of organisms (e. ... American Naturalist is a monthly scientific journal, founded in 1867, and associated with the University of Chicago. ...

In 1939,with Babcock's support, Stebbins was made a full professor in the Department of Genetics at UC Berkley, after failing to be promoted by the Department of Botany. Stebbins was required to teach a course on evolution, and during his preparation he became excited by contemporary research combining genetics and evolution. He became associated with a group known as the Bay Area Biosystematists, which included botanist Jens Clausen, taxonomist David Keck, physiologist William Hiesey and the evolutionary geneticist Theodosius Dobzhansky. With the encouragement of this group of scientists, Stebbins directed his research towards evolution. He became involved with the Society for the Study of Evolution in 1946, and was one of the few botanists involved with the organization. The Bay Area Biosystematists is a group of biologists, geneticists, paleontologists, and systematists that are also interested in evolution. ... Jens Christen Clausen (March 11, 1891 - November 22, 1969) was an Danish-American botanist, geneticist, and ecologist. ... Theodosius Grigorevich Dobzhansky (Russian — Феодосий Григорьевич Добржанский; sometimes anglicized to Theodore Dobzhansky; January 25, 1900 - December 18, 1975) was a noted geneticist and evolutionary biologist. ... The Society for the Study of Evolution was formed in the United States in 1946 to promote evolution and the integration of various fields of science concerned with evolution and to organize the publication of a scientific journal to report on new research on evolution across a variety of fileds. ...

His research on plant evolution also progressed during this period; he worked on the genetics of forage grasses, looking at polyploidy and the evolution on the Poaceae and publishing numerous papers on the subject though the 1940s. He produced an artificial autotetraploid grass from the diploid species Ehrharta erecta through treatment with the chromosome doubling agent colchicine. He was able to establish the plant in the field, and after 39 years of field trials was able to show that the autotetraploid was inferior to its diploid parent; thus, he linked the success of polyploid species to habitat change.^[3] Subfamilies There are 7 subfamilies: Subfamily Arundinoideae Subfamily Bambusoideae Subfamily Centothecoideae Subfamily Chloridoideae Subfamily Panicoideae Subfamily Pooideae Subfamily Stipoideae The true grasses are monocotyledonous plants (Class Liliopsida) in the Family Poaceae, also known as Gramineae. ... Binomial name Ehrharta erecta Lam. ... Colchicine is a highly poisonous alkaloid, originally extracted from plants of the genus Colchicum (Autumn crocus, also known as the Meadow saffron). Originally used to treat rheumatic complaints and especially gout, it was also prescribed for its cathartic and emetic effects. ...

In 1946, Stebbins was invited to present Columbia University's prestigious Jesup Lectures, on Dobzhansky's recommendation. In 1941, Edgar Anderson, whom Stebbins had met in 1930 and had taken interest in his work on hybridization in the genus Iris, and Ernst Mayr had copresented the series. Mayr later published his lectures as Systematics and the Origin of Species, which became one of the cornerstone publications of the modern evolutionary synthesis. Stebbins's 1946 lectures drew together the otherwise disparate fields of genetics, ecology, systematics, cytology, and paleontology. In 1950, the lectures were published as Variation and Evolution in Plants, which proved to be one of the most important books published in 20th-century botany; in this book, Stebbins presented a comprehensive synthesis of evolution. The book brought botanical science into the new synthesis of evolutionary theory, and became part of the canon of biological works written between 1936 and 1950 that formed the modern synthesis of evolution. Following its publication, Stebbins was regarded as one of the experts on modern evolutionary theory and is widely credited with the founding of the science of evolutionary botany. Columbia University is a private university in the Morningside Heights neighborhood of Manhattan, New York City. ... Edgar Anderson (November 9, 1897 - June 18, 1969) was an American botanist. ... Species See text. ... This article has been identified as possibly containing errors. ... Systematics and the Origin of Species is a book written by zoologist and evolutionary biologist Ernst Mayr that was first published in 1942. ... The modern evolutionary synthesis (often referred to simply as the modern synthesis or the evolutionary synthesis), neo-Darwinian synthesis or neo-Darwinism, generally denotes the combination of Charles Darwins theory of the evolution of species by natural selection, Gregor Mendels theory of genetics as the basis for biological... Variation and Evolution in Plants is a book written by G. Ledyard Stebbins. ...

UC Davis and later life

Stebbins took an appointment at the University of California, Davis in 1950, where he was a key figure in the establishment of the University's Department of Genetics. The focus of his research moved to incorporate newer areas, such as developmental morphology and genetics in crop plants, including barley. During his tenure at UC Davis, he trained more than 30 graduate students in genetics, developmental biology and agricultural science. His own broad research interests included the study of a wide range of plants, and he published extensively in systematics, morphology, cytology, genetics, plant geography and developmental biology, in addition to numerous reviews discussing the research of his contemporaries. Stebbins wrote several books during his time at UC Davis. These included Processes of Organic Evolution, The Basis of Progressive Evolution, and his follow-up to "Variation and Evolution", Flowering Plants: Evolution Above the Species Level (1974) following his delivery of the Prather Lectures at Harvard. He wrote Chromosomal Evolution in Plants and the textbook Evolution with co-authors Dobzhansky, Francisco Ayala and James Valentine. His final book was Darwin to DNA, Molecules to Humanity (1982). The University of California, Davis, commonly known as UC Davis, is one of the ten University of California campuses. ... Binomial name Hordeum vulgare L. Barley (Hordeum vulgare) is a major food and animal feed crop, a member of the grass family Poaceae. ... Francisco Jose Ayala (born 1934) is a Spanish American professor of biology and philosophy at the University of California, Irvine. ... James Burgon Valentine (born October 5, 1978 in Lincoln, Nebraska) is an American musician. ...

Stebbins was passionate about teaching evolution, and during the 1960s and 70s he was a vocal advocate for the teaching of Darwinian evolution in schools. He worked closely with the Biological Sciences and Curriculum Study to develop high school curricula l based on evolution as the central unifying principle in biology. Stebbins was active in numerous science organizations—including the International Union of Biological Sciences, the Western Society of Naturalists, the Botanical Society of America, and the Society for the Study of Evolution—and served as President of the American Society of Naturalists. He was elected to the National Academy of Sciences in 1952. Stebbins received numerous awards for his contributions to science: the National Medal of Science, the Gold Medal of the Linnean Society of London, the Addison Emery Verrill Medal from the Yale Peabody Museum, and the John Frederick Lewis Award from the American Philosophical Society. President Harding and the National Academy of Sciences at the White House, Washington, DC, April 1921 The National Academy of Sciences (NAS) is a corporation in the United States whose members serve pro bono as advisers to the nation on science, engineering, and medicine. ... National Medal of Science The National Medal of Science, also called the Presidential Medal of Science, is an honor given by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social... The American Philosophical Society, founded in 1743 by founding father Benjamin Franklin, continues to operate to this day. ...

Stebbins was active in conservation issues in California during his later life. He established the California Native Plant Society branch in Sacramento in the early 1960s. Through the society, he created an active field trip program to increase interest in the native flora of California and to document rare plants. Stebbins was the state President of the Society in 1966. The society was instrumental in preventing the destruction of a beach on the Monterey Peninsula that he referred to as "Evolution Hill"—the area is now known as the S.F.B. Morse Botanical Area. He was instrumental in the establishment of the Inventory of Rare and Endangered Vascular Plants of California, which is still used by state and federal bodies in the United States for conservation policy-making.^[4] In 1980, the University of California, Davis, named a parcel of land of 2.33 km² near Lake Beryessa, California, the Stebbins Cold Canyon Reserve, in recognition of his contributions to conservation and evolutionary science. The reserve is a part of the University of California Natural Reserve System. The California Native Plant Society (CNPS) is a California not-for-profit orgaiization that seeks to increase understanding of Californias native flora and to preserve that flora. ... Nickname: The Cradle of History, Californias First City Motto: {{{motto}}} Official website: http://www. ... The The University of California natural reserve system is the largest and most diverse set of university-owned and operated reserves in the world. ...

In 1973, Stebbins gave his last lectures at UC Davis, he was made emeritus professor, and following his retirement traveled widely, taught and visited colleagues for another for the next 20 years. His last paper, "A brief summary of my ideas on evolution", was published in the American Journal of Botany in 1999, in the same year he was given the Distinguished Service award from the American Institute of Biological Sciences. A colloquium was held by the National Academies of Science in 2000 to commemorate the 50th anniversary of the publication of Variation and Evolution in Plants. Following a cancer-related illness, Stebbins died in his home in Davis in that year. Stebbins was honored at a Unitarian memorial service—he had been active in the church in his later years following marriage to his second Barbara Monaghan Stebbins in the 1950s.^[5] His ashes were scattered at Stebbins Cold Canyon Reserve.^[6] The American Journal of Botany (ISSN 00029122) is a peer-reviewed scientific journal which includes research papers on all aspects of plant biology. ... Historic Unitarianism believed in the oneness of God as opposed to traditional Christian belief in the Trinity (Father, Son, and Holy Spirit). ...

Legacy

Stebbins made an enormous contribution to the literature of plant evolutionary biology, in addition to his seven book, he wrote more than 280 journal articles and book chapters, a compilation of which were published in 2004, The Scientific Papers of G. Ledyard Stebbins (1929–2000). Biographer Smocovitis, a history of science academic who is preparing a full-length biography on Stebbins,^[7] has described Stebbins's scientific strength as follows.

His ability to read quickly, recognize novel insights, digest new material, and then integrate the knowledge were the hallmarks of his scientific work style. He was a masterful synthesizer and master of the review essay or synthetic thought piece.^[5]

The UC Davis Herbarium maintains a G. Ledyard Stebbins student grant program, established in celebration of his 90th birthday.

References

Cited references

1. ^ Yoon C. K. January 21 2000. Ledyard Stebbins, 94, Dies; Applied Evolution to Plants. New York Times, Section B, Page 9
2. ^ Gustafsson, Å. 1946–1947. Apomixis in higher plants. C. W. K. Gleerup, Lund.
3. ^ Stebbins, G. L. 1985. Polyploidy, Hybridization, and the Invasion of New Habitats. Annals of the Missouri Botanical Garden 72:824-832
4. ^ Faber, P. M. 2000. G. Ledyard Stebbins Jr. 1906 - 2000. Fremontia 28:69-70
5. ^ ^a Smocovitis, V. B. 2001. G. Ledyard Stebbins and the evolutionary synthesis. Annual Review of Genetics 35:803-814
6. ^ Wright, S. January 28 2000. Pioneer biologist Stebbins dies. Dateline UC Davis
7. ^ Smocovitis, V. B. 1999. Living with Your Biographical Subject: Special Problems of Distance, Privacy and Trust in the Biography of G. Ledyard Stebbins Jr. Journal of the History of Biology 32:421–438

General references

• Mayr, E. 2002. G. Ledyard Stebbins. Proceedings of the American Philosophical Society 146:129-131
• Raven, P. H. 2000. G. Ledyard Stebbins (1906–2000): An appreciation. Proceedings of the National Academy of Sciences 97:6945-6946
• Smocovitis, V. B. 1997. G. Ledyard Stebbins, Jr. and the evolutionary synthesis (1924 - 1950). American Journal of Botany 84:1625-1637
• Smocovitis, V. B. and Ayala, F. J. 2000. George Ledyard Stebbins. Biographical Memoirs of the National Academy of Sciences 85:290-313

In botanical nomenclature, author citation refers to the person (or team) who valid published the name, i. ... u fuck in ua ... Botany is the scientific study of plant life. ... This is a list of botanists by their author abbreviation. ...

External links

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G. Ledyard Stebbins

• Full list of Stebbins' publications