Marcus Morton Rhoades (July 24, 1903 in

Graham, Missouri Graham is a city in Nodaway County, Missouri, United States. The population was 171 at the 2010 census. History Graham was originally called Jacksonville, and under the latter name was platted in 1856. The present name is after Col. Amos Graha ...

– December 30, 1991) was an

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

cytogeneticist Cytogenetics is essentially a branch of genetics, but is also a part of cell biology/cytology (a subdivision of human anatomy), that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis a ...

Education

He earned a Bachelor of Science degree in 1927, a Master of Science degree in 1928 from the

University of Michigan , mottoeng = "Arts, Knowledge, Truth" , former_names = Catholepistemiad, or University of Michigania (1817–1821) , budget = $10.3 billion (2021) , endowment = $17 billion (2021)As o ...

and a Ph.D. degree in 1932 from

Cornell University Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...

where he was a trainee of Rollins A. Emerson alongside future Nobel Prize winners

George Beadle George Wells Beadle (October 22, 1903 – June 9, 1989) was an American geneticist. In 1958 he shared one-half of the Nobel Prize in Physiology or Medicine with Edward Tatum for their discovery of the role of genes in regulating biochemical eve ...

and Barbara McClintock, and completed a thesis on the topic of

cytoplasmic male sterility Cytoplasmic male sterility is total or partial male sterility in plants as the result of specific nuclear and mitochondrial interactions. Male sterility is the failure of plants to produce functional anthers, pollen, or male gametes. Backgroun ...

in maize.http://www.nasonline.org/publications/biographical-memoirs/memoir-pdfs/rhoades-m-m.pdf

Career

After completing his doctoral studies, Rhoades's career spanned numerous institutions, first working as an experimentalist in plant breeding at Cornell University from 1932 to 1935, a research geneticist with the USDA in Ames, Iowa and later Arlington, Virginia from 1935 to 1940, an associate professor and later full professor at

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

from 1940 to 1948, a professor at

UIUC The University of Illinois Urbana-Champaign (U of I, Illinois, University of Illinois, or UIUC) is a public land-grant research university in Illinois in the twin cities of Champaign and Urbana. It is the flagship institution of the Uni ...

from 1948 to 1958, and finally at

Indiana University Indiana University (IU) is a system of public universities in the U.S. state of Indiana. Campuses Indiana University has two core campuses, five regional campuses, and two regional centers under the administration of IUPUI. *Indiana Universi ...

from 1948 until reaching maximum retirement age in 1974.http://www.genetics.org/content/genetics/133/1/1.full.pdf He was elected to the United States National Academy of Sciences in 1946, the

American Philosophical Society The American Philosophical Society (APS), founded in 1743 in Philadelphia, is a scholarly organization that promotes knowledge in the sciences and humanities through research, professional meetings, publications, library resources, and communit ...

in 1962, and the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, a ...

in 1966. Rhoades was active in the Genetics Society of America, serving as the editor of ''

Genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...

'' from 1940 to 1948, and later as the Vice President and then President of the GSA. His

research Research is " creative and systematic work undertaken to increase the stock of knowledge". It involves the collection, organization and analysis of evidence to increase understanding of a topic, characterized by a particular attentiveness ...

maize Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. The ...

led to important discoveries for basic

genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...

and the applied science of plant breeding. He was one of the first cytogenecists to document the pre-meiotic pairing of

homologous chromosomes A couple of homologous chromosomes, or homologs, are a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization. Homologs have the same genes in the same loci where they provide points alon ...

in maize, otherwise referred to as somatic pairing (Singh, 2003), and the first to document an instance of

meiotic drive Meiotic drive is a type of intragenomic conflict, whereby one or more loci within a genome will effect a manipulation of the meiotic process in such a way as to favor the transmission of one or more alleles over another, regardless of its phenoty ...

, a Mendelian inheritance caused by preferential segregation of certain versions of homologous chromosomes during meiosis. Rhoades also pioneered work in nuclear-cytoplasmic interactions, demonstrating that mutation of the nuclear gene ''iojap'' produced heritable mutations in the genome of chloroplasts which persisted after the nuclear mutation was segregated away. In 1907,

Herbert J. Webber Herbert John Webber (December 27, 1865 – January 18, 1946) was an American plant physiologist, professor emeritus of sub-tropical horticulture, first director of the University of California Citrus Experiment Station, and the third curator of th ...

started the Synapsis Club, a student/faculty organization at

. Prof. Rollins A. Emerson continued and encouraged his students to become members, including Rhoades. In the 1940s, Rhoades served as the doctoral advisor of geneticist Ruth Sager at

. The M. Rhoades Early-Career Award, awarded annually by the maize genetics community for significant contributions to genetics research in maize or related species, was named in honor of Rhoades.

Awards

* 1977 Foreign Fellow of the Royal Danish Academy of Science and Letters * 1981

Thomas Hunt Morgan Medal The Thomas Hunt Morgan Medal is awarded by the Genetics Society of America (GSA) for lifetime contributions to the field of genetics. The medal is named after Thomas Hunt Morgan, the 1933 Nobel Prize winner, who received this award for his work wi ...

- ( Genetics Society of America) - inaugural award, shared with Barbara McClintock

References

*Carlson, W.R. and Birchler, J.A
Marcus Morton Rhoades, Biographical Memoirs of the National Academy of Sciences
*Singh, R.J. 2003. Plant cytogenetics. CRC Press, USA 1903 births 1991 deaths American geneticists University of Michigan alumni Cornell University alumni Members of the United States National Academy of Sciences Genetics (journal) editors {{US-biologist-stub Members of the American Philosophical Society Fellows of the American Academy of Arts and Sciences