Marcus Morton Rhoades (July 24, 1903 in Graham, Missouri – December 30, 1991) was an American

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 an ...

Education

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

University of Michigan The University of Michigan (U-M, U of M, or Michigan) is a public university, public research university in Ann Arbor, Michigan, United States. Founded in 1817, it is the oldest institution of higher education in the state. The University of Mi ...

and a Ph.D. degree in 1932 from

Cornell University Cornell University is a Private university, private Ivy League research university based in Ithaca, New York, United States. The university was co-founded by American philanthropist Ezra Cornell and historian and educator Andrew Dickson W ...

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 Barbara McClintock (June 16, 1902 – September 2, 1992) was an American scientist and cytogenetics, cytogeneticist who was awarded the 1983 Nobel Prize in Physiology or Medicine. McClintock received her PhD in botany from Cornell University ...

, and completed a thesis on the topic of cytoplasmic male sterility in maize.

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 Ames () is a city in Story County, Iowa, United States, located approximately north of Des Moines, Iowa, Des Moines in central Iowa. It is the home of Iowa State University (ISU). According to the 2020 United States census, 2020 census, Ames ha ...

and later Arlington, Virginia from 1935 to 1940, an associate professor and later full professor at

Columbia University Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...

from 1940 to 1948, a professor at the

University of Illinois The University of Illinois Urbana-Champaign (UIUC, U of I, Illinois, or University of Illinois) is a public university, public land-grant university, land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United ...

from 1948 to 1958, and finally at

Indiana University Indiana University (IU) is a state university system, system of Public university, public universities in the U.S. state of Indiana. The system has two core campuses, five regional campuses, and two regional centers under the administration o ...

from 1948 until reaching maximum retirement age in 1974. He was elected to the United States

National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, NGO, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the ...

in 1946, the

American Philosophical Society The American Philosophical Society (APS) is an American scholarly organization and learned society founded in 1743 in Philadelphia that promotes knowledge in the humanities and natural sciences through research, professional meetings, publicat ...

in 1962, and the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) 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, and other ...

in 1966. Rhoades was active in the

Genetics Society of America The Genetics Society of America (GSA) is a scholarly membership society of more than 5,500 genetics researchers and educators, established in 1931. The Society was formed from the reorganization of the Joint Genetics Sections of the American Soc ...

, 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 Augustinians, Augustinian ...

'' 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 to ...

maize Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout grass that produces cereal grain. It was domesticated by indigenous peoples in southern Mexico about 9,000 years ago from wild teosinte. Native American ...

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 Augustinians, Augustinian ...

and the

applied science Applied science is the application of the scientific method and scientific knowledge to attain practical goals. It includes a broad range of disciplines, such as engineering and medicine. Applied science is often contrasted with basic science, ...

plant breeding Plant breeding is the science of changing the traits of plants in order to produce desired characteristics. It is used to improve the quality of plant products for use by humans and animals. The goals of plant breeding are to produce crop varie ...

. He was one of the first cytogenecists to document the pre-meiotic pairing of

homologous chromosomes Homologous chromosomes or homologs are a set of one maternal and one paternal chromosome that pair up with each other inside a cell during meiosis. Homologs have the same genes in the same locus (genetics), loci, where they provide points along e ...

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 affect 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 phenot ...

, 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 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 w ...

- (

) - 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