Background

Calvin B. Bridges was born on January 11, 1889, in Schuyler Falls, New York, the only child of Leonard Victor Bridges and Amelia Charlotte Blackman. Tragically, Calvin's mother died when he was two years old, and his father died a year later, leaving the young Calvin an orphan. Bridges was subsequently taken in and raised by his grandmother.

Education

When Calvin Bridges was fourteen, he was sent to Plattsburg to attend high school. Because of his deficient primary school training and because he worked to help support himself, he did not graduate from high school until he was twenty. His record was good enough, however, for him to be offered scholarships at both Cornell and Columbia. He chose the latter and entered as a freshman in 1909.

During his first year at Columbia, he took a biology course taught by Morgan. In his sophomore year, Bridges was given a position as an assistant in Morgan’s lab at Columbia University. At that time, Morgan studied heredity using Drosophila, which required Morgan to breed flies in milk bottles. Bridges initially cleaned the bottles.

In 1912, after three years of school, Bridges graduated from Columbia with a Bachelor of Science degree.

After receiving his undergraduate degree, Bridges earned his Doctor of Philosophy degree in zoology from Columbia University in 1916.

Career

After graduation, Calvin Bridges worked with Morgan as a research associate of the Carnegie Institution of Washington. His pioneering work helped prove that genes on chromosomes pass along hereditary traits. It helped advance the understanding of how abnormalities in chromosome structure are related to changes in physical traits and how the sex of an organism is genetically determined. By studying chromosomes with missing segments, Bridges also constructed some of the earliest chromosome maps. Bridges, with Morgan and Alfred Henry Sturtevant, published these results in 1925. That same year he published "Sex in Relation to Chromosomes and Genes," demonstrating that sex in Drosophila is not determined simply by the "sex chromosomes" (X and Y) but is the result of a "chromosomal balance" - a mathematical ratio of the number of female sex chromosomes (X) to the number of "nonsex" chromosomes (autosomes).

In 1928 Bridges moved with Morgan to the California Institute of Technology, Pasadena, where he constructed detailed gene maps of the giant chromosomes found in the salivary gland cells of the fruit fly larva. Later he discovered an important class of Drosophila mutants caused by gene duplications.

Achievements

• Calvin Blackman Bridges is remembered as a geneticist, whose pioneering work helped formulate important basic concepts. Bridges helped prove that genes on chromosomes pass along hereditary traits and helped advance the understanding of how chromosomal abnormalities are linked to changes in physical traits.

Works

More photos

• book

  • Non-Disjunction as Proof of the Chromosome Theory of Heredity

    (There are now about fifty sex-linked mutations known in D...)

    1916
  • Sex-linked Inheritance in Drosophila 1916
  • Contributions to the genetics of Drosophila melanogaster 1919
  • The Third-chromosome Group of Mutant Characters of Drosophila Melanogaster 1923
  • Report of Investigations on the Constitution of the Germinal Material in Relation to Heredity 1936

Politics

Politically Calvin B. Bridges was rather far to the left - a circumstance related to his visit to Russia in 1931 - 1932.

Views

In his personal and social relations, Calvin Bridges was a nonconformist, largely as a matter of principle.

Membership

• 

  In 1936, Calvin Bridges was elected to the National Academy of Sciences for his work with Drosophila.

  National Academy of Sciences , United States

  1936

Personality

Calvin B. Bridges was a friendly and generous person.

Connections

On September 7, 1912, Calvin B. Bridges married Gertrude Frances Ives. The couple had four children.

Father:

Leonard Victor Bridges

Mother:

Amelia Charlotte Bridges (Blackman)

Wife:

Gertrude Frances Bridges (Ives)

Son:

Philip Newell Bridges

Son:

Norman Ives

Daughter:

Betsy Blackman Bridges

Son:

Nathan Ives Bridges

colleague:

Thomas Hunt Morgan

Thomas Hunt Morgan was an American zoologist, evolutionary biologist, geneticist, embryologist, educator, and science author, whose research won the Nobel Prize in Physiology or Medicine in 1933.

colleague:

Alfred Sturtevant

Alfred Sturtevant and Calvin Bridges were both students of Thomas Hunt Morgan. Sturtevant provided proof of genetic linkage. Bridges advanced the theory of chromosomal non-disjunction, and did a lot of work on chromosomal banding patterns.

colleague:

Hermann Joseph Muller

Hermann Joseph Muller was an American geneticist, educator, and Nobel laureate best known for his work on the physiological and genetic effects of radiation (mutagenesis), as well as his outspoken political beliefs.

Along with Alfred Sturtevant and H.J. Muller, Calvin Bridges was part of Thomas Hunt Morgan's famous "Fly Room" at Columbia University.

References

• A History of Genetics
  1965