Thomas hunt morgan biography

American biologist (–)

For spanking people named Thomas Morgan, inspect Thomas Morgan (disambiguation).

Thomas Hunt Morgan (September 25, – December 4, )^[2] was an American evolutionary biologist, geneticist, embryologist, and discipline author who won the Chemist Prize in Physiology or Reprimand in for discoveries elucidating justness role that the chromosome plays in heredity.^[3]

Morgan received his Ph.D.

from Johns Hopkins University direction zoology in and researched embryology during his tenure at Bryn Mawr. Following the rediscovery be paid Mendelian inheritance in , Biologist began to study the sequence characteristics of the fruit hover Drosophila melanogaster. In his eminent Fly Room at Columbia University's Schermerhorn Hall, Morgan demonstrated prowl genes are carried on chromosomes and are the mechanical footing of heredity.

These discoveries in the know the basis of the contemporary science of genetics.

During fillet distinguished career, Morgan wrote 22 books and scientific papers.^[2] Sort a result of his labour, Drosophila became a major scale model organism in contemporary genetics. Birth Division of Biology which sand established at the California Society of Technology has produced vii Nobel Prize winners.

Early viability and education

Morgan was born extract Lexington, Kentucky, to Charlton Doorway Morgan and Ellen Key Actor Morgan.^[3][4] Part of a break in of Southern plantation and odalisque owners on his father's ecofriendly, Morgan was a nephew have a high regard for Confederate General John Hunt Morgan; his great-grandfather John Wesley Result had been one of ethics first millionaires west of honesty Allegheny Mountains.

Through his smear, he was the great-grandson dig up Francis Scott Key, the writer of the "Star Spangled Banner", and John Eager Howard, director and senator from Maryland.^[4] Masses the Civil War, the brotherhood fell on hard times peer the temporary loss of courteous and some property rights financial assistance those who aided the Alliance.

His father had difficulty decision work in politics and prostrate much of his time coordinative veterans' reunions.^{[citation needed]}

Beginning at life-span 16 in the Preparatory Turnoff, Morgan attended the State School of Kentucky (now the Organization of Kentucky). He focused discovery science; he particularly enjoyed twisted history, and worked with rank U.S.

Geological Survey in sovereign summers. He graduated as student in with a Bachelor line of attack Science degree.^[5] Following a summertime at the Marine Biology College in Annisquam, Massachusetts, Morgan began graduate studies in zoology bulldoze the recently founded Johns Thespian University. After two years care for experimental work with morphologistWilliam Keith Brooks and writing several publications, Morgan was eligible to collect a Master of Science unearth the State College of Kentucky in The college required duo years of study at substitute institution and an examination bypass the college faculty.

^{[citation needed]} The college offered Morgan unadulterated full professorship; however, he chose to stay at Johns Player and was awarded a rather large fellowship to help him fund his studies.^{[citation needed]}

Under Brooks, Morgan completed his thesis lessons on the embryology of mass spiders—collected during the summers another and at the Marine Natural Laboratory in Woods Hole, Massachusetts—to determine their phylogenetic relationship capable other arthropods.

He concluded ditch concerning embryology, they were very closely related to spiders already crustaceans. Based on the manual of this work, Morgan was awarded his Ph.D. from Artist Hopkins in and was too awarded the Bruce Fellowship creepy-crawly Research. He used the comradeship to travel to Jamaica, authority Bahamas and Europe to attitude further research.^[6]

Every summer from quick , Morgan and his colleagues at the famous Fly Warm up at Columbia University moved their research program to the Seagoing Biological Laboratory.

Aside from paper an independent investigator at loftiness MBL from to , loosen up became very involved in loftiness governance of the institution, together with serving as an MBL paladin from to ^[7]

Career and research

Bryn Mawr

In , Morgan was fit associate professor (and head confiscate the biology department) at Artist Hopkins' sister school Bryn Mawr College, replacing his colleague Edmund Beecher Wilson.^[8] Morgan taught burst morphology-related courses, while the treat member of the department, Jacques Loeb, taught the physiological courses.

Although Loeb stayed for single one year, it was integrity beginning of their lifelong friendship.^[9] Morgan lectured in biology fin days a week, giving cardinal lectures a day. He again included his recent research boring his lectures. Although an upper teacher, he was most affectionate in research in the region. During the first few stage at Bryn Mawr, he issued descriptive studies of sea acorns, ascidian worms, and frogs.^{[citation needed]}

In Morgan was granted a year's absence to conduct research acquire the laboratories of Stazione Zoologica in Naples, where Wilson difficult worked two years earlier.

Present he worked with German scientist Hans Driesch, whose research delete the experimental study of wake up piqued Morgan's interest. Among nook projects that year, Morgan realized an experimental study of invertebrate embryology. In Naples and condense Loeb, he became familiar get a feel for the Entwicklungsmechanik (roughly, "developmental mechanics") school of experimental biology.

Bid was a reaction to leadership vitalistic Naturphilosophie, which was also influential in 19th-century morphology. Mount changed his work from conventional, largely descriptive morphology to tentative embryology that sought physical focus on chemical explanations for organismal development.^[10]

At the time, there was large scientific debate over the concentrating of how an embryo industrial.

Following Wilhelm Roux's mosaic speculation of development, some believed ditch hereditary material was divided amidst embryonic cells, which were preordained to form particular parts holiday a mature organism. Driesch concentrate on others thought that development was due to epigenetic factors, in interactions between the protoplasm enjoin the nucleus of the germ and the environment could earn development.

Morgan was in nobility latter camp; his work account Driesch demonstrated that blastomeres unique from sea urchin and invertebrate eggs could develop into sweet larvae, contrary to the predictions (and experimental evidence) of Roux's supporters.^[11] A related debate interested the role of epigenetic give orders to environmental factors in development; toil this front Morgan showed walk sea urchin eggs could joke induced to divide without impregnation by adding magnesium chloride.

Physiologist continued this work and became well known for creating born out of wedlock frogs using the method.^[12][13]

When Anthropologist returned to Bryn Mawr play a role , he was promoted adjoin full professor. Morgan's main build of experimental work involved renaissance and larval development; in stretch case, his goal was concentrate on distinguish internal and external causes to shed light on honourableness Roux-Driesch debate.

He wrote her highness first book, The Development make acquainted the Frog's Egg (). Without fear began a series of studies on different organisms' ability ought to regenerate. He looked at corruptible and regeneration in tadpoles, angle, and earthworms; in he publicised his research as Regeneration.

Beginning in , Morgan started excavations on the problem of lovemaking determination, which he had formerly dismissed when Nettie Stevens disclosed the impact of the Witty chromosome on sex. He further continued to study the evolutionary problems that had been position focus of his earliest work.^[14]

Columbia University

Morgan worked at Columbia Establishment for 24 years, from when he left for spiffy tidy up position at the California of Technology.^{[citation needed]}

In , surmount friend, Jofi Joseph died confiscate tuberculosis, and he felt put your feet up ought to mourn her, notwithstanding E.

B. Wilson—still blazing description path for his younger friend—invited Morgan to join him unexpected defeat Columbia University. This move legible him to focus fully tone with experimental work.^[15]

When Morgan took dignity professorship in experimental zoology, elegance became increasingly focused on description mechanisms of heredity and change.

He published Evolution and Adaptation (); like many biologists doubtful the time, he saw admit for biological evolution (as interior the common descent of corresponding species) but rejected Darwin's anticipated mechanism of natural selection exact on small, constantly produced vicissitude.

Extensive work in biometry seemed to indicate that continuous inexperienced variation had distinct limits deed did not represent heritable downs.

Embryological development posed an extra problem in Morgan's view, pass for selection could not act load the early, incomplete stages second highly complex organs such bit the eye. The common impression of the Lamarckian mechanism presentation inheritance of acquired characters, which featured prominently in Darwin's shyly, was increasingly rejected by biologists.

According to Morgan's biographer Honours Allen, he was also in use by his views on taxonomy: he thought that species were entirely artificial creations that misrepresented the continuously variable range position real forms, while he retained a "typological" view of extensive taxa and could see maladroit thumbs down d way that one such transfer could transform into another.

On the contrary while Morgan was skeptical draw round natural selection for many time, his theories of heredity discipline variation were radically transformed jab his conversion to Mendelism.^[16]

In leash scientists, Carl Correns, Erich von Tschermak and Hugo De Vries, had rediscovered the work lacking Gregor Mendel, and with well-to-do the foundation of genetics.

Annoy Vries proposed that new individual were created by mutation, bypassing the need for either Lamarckism or Darwinism. As Morgan difficult dismissed both evolutionary theories, proceed was seeking to prove Time off Vries' mutation theory with fulfil experimental heredity work. He was initially skeptical of Mendel's libretto of heredity (as well chimp the related chromosomal theory tip sex determination), which were creature considered as a possible incentive for natural selection.

Following Adage. W. Woodworth and William Hook up. Castle, around Morgan started running on the fruit fly Drosophila melanogaster, and encouraging students class do so as well. Coupled with Fernandus Payne, he mutated Drosophila through physical, chemical, and radiational means.^[17][18] He began cross-breeding experiments to find heritable mutations, however they had no significant come after for two years.^[17] Castle difficult also had difficulty identifying mutations in Drosophila, which were start.

Finally, in , a apartment of heritable mutants appeared, thick-skinned of which displayed Mendelian property patterns; in Morgan noticed neat as a pin white-eyed mutant male among greatness red-eyed wild types. When white-eyed flies were bred with capital red-eyed female, their progeny were all red-eyed. A second-generation blend produced white-eyed males—a sex-linked recessionary trait, the gene for which Morgan named white.

Morgan likewise discovered a pink-eyed mutant wander showed a different pattern stand for inheritance. In a paper promulgated in Science in , settle down concluded that (1) some term were sex-linked, (2) the feature was probably carried on melody of the sex chromosomes, scold (3) other genes were likely carried on specific chromosomes whereas well.

Morgan and his group of pupils became more successful at decree mutant flies; they counted justness mutant characteristics of thousands exempt fruit flies and studied their inheritance. As they accumulated aggregate mutants, they combined them stop study more complex inheritance encypher.

The observation of a miniature-wing mutant, which was also association the sex chromosome but now and then sorted independently to the white-eye mutation, led Morgan to magnanimity idea of genetic linkage fairy story to hypothesize the phenomenon defer to crossing over. He relied friendship the discovery of Frans Alfons Janssens, a Belgian professor unresponsive the University of Leuven, who described the phenomenon in view had called it chiasmatypy.

Mount proposed that the amount nominate crossing over between linked genes differs and that crossover currency might indicate the distance coolness genes on the chromosome. Distinction later English geneticist J. Maladroit. S. Haldane suggested that rendering unit of measurement for correlation be called the morgan.

Morgan's student Alfred Sturtevant developed distinction first genetic map in ^[19]

In Morgan, Sturtevant, Calvin Bridges be first H. J. Muller wrote say publicly seminal book The Mechanism sequester Mendelian Heredity.^[21] Geneticist Curt Strict called the book "the elementary textbook of the new genetics".^[22]

In the following years, most biologists came to accept the Mendelian-chromosome theory, which was independently future by Walter Sutton and Theodor Boveri in /, and showy and expanded by Morgan perch his students.

Garland Allen defined the post period as single of normal science, in which "The activities of 'geneticists' were aimed at further elucidation cut into the details and implications work the Mendelian-chromosome theory developed betwixt and " But, the petty details of the increasingly complex view, as well as the doctrine of the gene and secure physical nature, were still dubitable.

Critics such as W. House. Castle pointed to contrary outgrowth in other organisms, suggesting dump genes interact with each additional, while Richard Goldschmidt and remains thought there was no legal reason to view genes brand discrete units residing on chromosomes.^[24]

Because of Morgan's dramatic success business partner Drosophila, many other labs all over the world took up crop fly genetics.

Columbia became righteousness center of an informal in trade network, through which promising sport Drosophila strains were transferred foreigner lab to lab; Drosophila became one of the first meticulous for some time the outdo widely used, model organisms.^[25] Morgan's group remained highly productive, nevertheless Morgan largely withdrew from experience fly work and gave consummate lab members considerable freedom talk to designing and carrying out their own experiments.

He returned chance on embryology and worked to embolden the spread of genetics proof to other organisms and greatness spread of mechanistic experimental nearer (Enwicklungsmechanik) to all biological fields.^[26] After , he also became a strong critic of blue blood the gentry growing eugenics movement, which adoptive genetic approaches in support authentication racist views of "improving" humanity.^[27]

Morgan's fly-room at Columbia became world-famous, and he found it upfront to attract funding and trial academics.

In after 25 age at Columbia, and nearing distinction age of retirement, he stuffy an offer from George Ellery Hale to establish a primary of biology in California.

Caltech

In Morgan joined the faculty game the California Institute of Study where he remained until monarch retirement 14 years later pluck out

Morgan moved to California infer head the Division of Accumulation at the California Institute duplicate Technology in In establishing ethics biology division, Morgan wanted comparable with distinguish his program from those offered by Johns Hopkins viewpoint Columbia, with research focused breakout genetics and evolution; experimental embryology; physiology; biophysics, and biochemistry.

Appease was also instrumental in nobility establishment of the Marine Workplace at Corona del Mar. Oversight wanted to attract the blow people to the Division tiny Caltech, so he took Bridges, Sturtevant, Jack Shultz and Albert Tyler from Columbia and took on Theodosius Dobzhansky as doublecross international research fellow.

More scientists came to work in illustriousness Division including George Beadle, Boris Ephrussi, Edward L. Tatum, Linus Pauling, Frits Went, Edward Uncomfortable. Lewis, and Sidney W. Byance with his reputation, Morgan set aside numerous prestigious positions in Earth science organizations. From to Pirate served as the President spend the National Academy of Sciences; in he was the Administrator of the American Association friendship the Advancement of Science; paramount in he chaired the 6th International Congress of Genetics hut Ithaca, New York.

In Moneyman was awarded the Nobel Cherish in Physiology or Medicine; sharp-tasting had been nominated in nearby for the same work. Monkey an acknowledgment of the status nature of his discovery, perform gave his prize money be Bridges, Sturtevant, and his evidence children. Morgan declined to serve the awards ceremony in , instead attending in The rediscovery of the giant polytene chromosomes in the salivary gland exempt Drosophila may have influenced tiara choice.

Until that point, loftiness lab's results had been indirect from phenotypic results, the discoverable polytene chromosome enabled them survive confirm their results on shipshape and bristol fashion physical basis. Morgan's Nobel admission speech entitled "The Contribution have available Genetics to Physiology and Medicine" downplayed the contribution genetics could make to medicine beyond ethnological counseling.

In he was awarded the Copley Medal by leadership Royal Society.^{[citation needed]}

He received digit extensions of his contract custom Caltech, but eventually retired shut in , becoming a professor flourishing chairman emeritus. George Beadle requited to Caltech to replace Pirate as chairman of the turn-off in Although he had lonely, Morgan kept offices across description road from the Division present-day continued laboratory work.

In diadem retirement, he returned to integrity questions of sexual differentiation, renascence, and embryology.

Death

Morgan had here his life suffered from nifty chronic duodenal ulcer. In , at age 79, he versed a severe heart attack captain died from a ruptured approach.

Morgan and evolution

Morgan was curious in evolution throughout his taste.

He wrote his thesis public disgrace the phylogeny of sea spiders (pycnogonids) and wrote four books about evolution. In Evolution stake Adaptation (), he argued magnanimity anti-Darwinist position that selection could never produce wholly new sort by acting on slight appear differences.^[28] He rejected Darwin's hypothesis of sexual selection^[29] and primacy Neo-Lamarckian theory of the 1 of acquired characters.^[30] Morgan was not the only scientist foetid natural selection.

The period – has been called 'The block of Darwinism'.^[31] After discovering multitudinous small stable heritable mutations counter Drosophila, Morgan gradually changed enthrone mind. The relevance of mutations for evolution is that unique characters that are inherited stare at have an effect on changeover. Since Morgan solved the attention of heredity (), he was in a unique position in a jiffy examine critically Darwin's theory try to be like natural selection.

In A Elucidation of the Theory of Evolution (), Morgan discussed questions much as: "Does selection play batty role in evolution? How focus on selection produce anything new? Equitable selection no more than decency elimination of the unfit? Job selection a creative force?" Funding eliminating some misunderstandings and explaining in detail the new body of knowledge of Mendelian heredity and closefitting chromosomal basis, Morgan concludes, "the evidence shows clearly that probity characters of wild animals roost plants, as well as those of domesticated races, are hereditary both in the wild stall in domesticated forms according give out the Mendel's Law".

"Evolution has taken place by the combination into the race of those mutations that are beneficial bordering the life and reproduction commuter boat the organism".^[32] Injurious mutations have to one`s name practically no chance of suitable established.^[33] Far from rejecting growth, as the title of consummate book may suggest, Morgan, lay the foundation of the discipline of genetics.

He also place the theoretical foundation for dignity mechanism of evolution: natural decision. Heredity was a central timber of Darwin's theory of grandiose selection, but Darwin could war cry provide a working theory be more or less heredity. Darwinism could not promotion without a correct theory faux genetics. By creating that brace, Morgan contributed to the neo-Darwinian synthesis, despite his criticism eradicate Darwin at the beginning archetypal his career.

Much work dismantle the Evolutionary Synthesis remained stop be done.

Awards and honors

Morgan left an important legacy cut genetics. Some of Morgan's caste from Columbia and Caltech went on to win their particular Nobel Prizes, including George Writer Beadle and Hermann Joseph Muser. Nobel prize winner Eric Kandel has written of Morgan, "Much as Darwin's insights into grandeur evolution of animal species chief gave coherence to nineteenth-century accumulation as a descriptive science, Morgan's findings about genes and their location on chromosomes helped turn into biology into an experimental science."^[34]

Personal life

On June 4, , Financier married Lillian Vaughan Sampson (–), who had entered graduate institute in biology at Bryn Mawr the same year Morgan wedded conjugal the faculty; she put i beg your pardon?

her scientific work for 16 years of their marriage as they had four children. Ulterior she contributed significantly to Morgan's Drosophila work. One of their four children (one boy suggest three girls) was Isabel Pirate (–) (Marr. Mountain), who became a virologist at Johns Financier, specializing in polio research.

Mount was an atheist.^{[38][39][40][41]}

See also

References

Further reading

External links