Detailed biography of Thomas Morgan the artist. Biography

Physiology or Medicine, 1933.

Born September 25, 1866 in Lexington, (Kentucky, USA) in the family of a diplomat. He graduated from the University of Kentucky, in 1886 received a bachelor's degree. After graduation, he worked at Johns Hopkins University.

In 1888-1889 he was engaged in scientific research in the American Committee on Fisheries.

In 1890 he received his doctorate from Johns Hopkins University and in the same year - an Adam Bruce scholarship, which allowed him to travel to Europe, to the Marine Zoological Laboratory. There he met Hans Drich and Kurt Herbst. It was under the influence of Drich that Morgan began to take an interest in experimental embryology.

From 1904 to 1928 he was professor of experimental zoology at Columbia University ( NY), and from 1928 to 1945 - professor of biology and laboratory director at California Institute of Technology(Pasadena). V last years life acquired a small laboratory in Corona del Mar (California).

In one of his early works, Morgan criticizes Mendelian theory of heredity. He believed that chromosomes are not carriers of heredity, but are products of early stages of development ( cm. MENDEL, GREGOR JOHANN). He also did not support Darwin's idea of "gradual change", preferring the version of the Dutch botanist Hugo de Vries that the emergence of a new species is the result of mutations ( cm. POPULATION GENETICS).

At that time, almost nothing was known about the mechanism of inheritance, and the method of studying the process of evolution and heredity was to compare the morphology and physiology of representatives of different species. Based on the data obtained, scientists tried to draw conclusions about the reasons for the similarities or differences between existing species. Morgan was no exception, his first work on the study of heredity was carried out in accordance with the generally accepted methodology. By 1891, he had completely mastered the comparative and descriptive methods of research, but they did not give answers to questions of interest to him, and he turned to experiments, hoping to get a specific result. In 1897, studying the ability of some organisms to restore lost body parts, he published the first article on the phenomenon of regeneration, contributing to the successful survival of the species.

In 1900, the focus of geneticists around the world was Mendel's work on the inheritance of traits in peas. In these works, Mendel argued that traits are inherited, obeying strict mathematical laws.

In 1902, the biologist W. Sutton suggested that heredity units (genes) are located inside or on the surface of structures of the cell nucleus, called chromosomes.

Morgan disagreed with this, believing that chromosomes are products of an early stage in the development of an organism.

In 1909, Morgan began working with the fruit fly Drosophila.

Back in 1900-1901, K.V. Woodworth studied Drosophila as an experimental material and was the first to suggest that Drosophila could be used in genetic research, in particular, to study closely related reproduction. Drosophila has only 4 pairs of chromosomes, it begins to multiply two weeks after its birth and after 12 days it brings offspring of 1000 individuals. V.E. Castle and F.E. Lutz also worked with Drosophila, who introduced the results of his work to Morgan, who was looking for cheaper experimental material for his scientific research.

Very soon (in 1909) the first mutations appeared. The subsequent study of this phenomenon ultimately allowed the scientist to establish exact location genes and how they work. One of the most important discoveries can be considered the "dependence" of certain mutations on sex (Morgan called this phenomenon "linkage" of genes): white eyes in fruit flies were transmitted only to males. After processing a large amount of information, Morgan came to an interesting conclusion: genes located on the same chromosome were inherited together much less often than one might expect. Therefore, chromosome splitting and the exchange of genetic material between chromosomes are possible. The further apart genes are located on a chromosome, the higher the likelihood of their rupture. On the basis of this, Morgan and his colleagues compiled "maps" of the chromosomes of Drosophila. His conjecture about the "linear" arrangement of genes in the chromosome, and that the "linkage" of genes depends on the distance of one gene from another, is one of the revolutionary discoveries in genetics.

In 1919 he was elected a Foreign Member of the Royal Society of London, in 1924 he was awarded the Darwin Medal; in 1933 he received the Nobel Prize for discoveries related to the functions of chromosomes in the transmission of heredity.

Morgan died in 1945 in Pasadena.

Major works: Regeneration... N-Y: Macmillan, 1901; Heredity and sex... N-Y: Columbia Univ. Press, 1913; The Theory of the Gene... New Haven, CT: Yale Univ. Press, 1932; The Scientific Basis of Evolution... London: Faber and Faber, 1932.

Irina Shanina

morgan scientist chromosome heredity

Thomas Morgan and his students (G. J. Möller, A. G. Stertevant and others) substantiated the chromosomal theory of heredity; the established patterns of the location of genes in chromosomes contributed to the elucidation of the cytological mechanisms of Gregor Mendel's laws and the development of the genetic foundations of the theory of natural selection.

Surprisingly, many scientific discoveries are based not only on strong knowledge, talent and perseverance. Often, intuition and luck are essential to success. For example, the extraordinary success of Mendel's experiments is largely due to the fact that the scientist intuitively chose a wonderful object for experiments - peas. The ensuing failure, which forced Mendel to abandon further research, was also the result of the choice of test objects - this time unsuccessful. For his research, Morgan chose not just a successful, but an ideal object, which over time became the most famous genetic model - the fruit fly Drosophila (Fig. 22).

Drosophila has become an ideal object for genetic research due to its properties: the fly has only 4 pairs of chromosomes, its life cycle is 10-20 days, during which one female gives about 400 offspring.

Fruit flies are easy to study throughout their life. In addition, the cells of the salivary glands of Drosophila larvae have giant chromosomes, which are very convenient for research, since they do not need microscopes with very high magnification.

Since 1908, Morgan began his research. First, he bought fruit flies from grocery and fruit stores.

He caught them with a net, having received permission for this from the owners of the shops, who made fun of the eccentric flycatcher. The thirty-five-meter experiment room, the so-called "fly-room" at Columbia University, where Morgan conducted his research, quickly became the talk of the town. The whole room was filled with bottles, jars, bowls and flasks, in which thousands of flies flew, voracious larvae swarmed, all the glasses of these vessels were hung with fruit fly pupae. There weren't enough bottles, and it was rumored that early in the morning, on their way to the lab, Morgan and his students stole milk bottles that Manhattan residents had thrown outside the door in the evening!

Morgan studied the flies he raised. It turned out that they outwardly are quite different: in addition to the usual red-eyed flies, there are white-eyed, yellow-eyed and even pink-eyed flies. There are flies with long and short wings and flies with twisted, wrinkled wings that cannot fly. Drosophila differ in the shape and color of the abdomen, legs, antennae and even the bristles that cover their body.

Morgan crossed fruit flies, following the inheritance of a huge number of all these traits. Analyzing the results of observations, he came to the conclusion that some traits are transmitted to descendants together. Based on this, Morgan suggested that the genes that determine these "linked" traits are not scattered throughout the cell, but linked in special "islets". It turned out that all hereditary traits of a fly are divided into four "linked" groups. It was already known that Drosophila has four pairs of chromosomes. From this, Morgan concluded that genes are localized in chromosomes, and each chromosome contains a chain of hundreds of genes. The scientist found: the greater the distance between two genes in a chromosome, the higher the probability of chain breaking - genes located close are extremely rare. Based on these observations, Morgan made maps of the location of genes in the chromosomes of Drosophila. This happened a year after the approval of the term gene in science.

In addition, Morgan found that some traits are transmitted only to males or only to females. He concluded that the genes responsible for these traits are located on the chromosomes that determine sex. So they discovered the existence of sex chromosomes.

The result of Morgan's research on fruit flies was the chromosomal theory of heredity. We will study it a little later. The main postulate of this theory is this: the material basis of heredity is represented by chromosomes, in which genes are localized.

In 1933, Thomas Morgan was awarded Nobel Prize in Physiology and Medicine "For discoveries related to the role of chromosomes in heredity." He is the only one of the ancestors of genetics who has received such an honor.

Thus, at the very beginning of the history of genetics, two fundamental milestones can be distinguished that determined the essence of this science. The first is the stage of hybridological research, which began with Mendel's experiments, which proved the existence of some discrete hereditary factors that are passed from parents to descendants, obeying certain mathematical laws. The second - cytological studies, based primarily on the experiments of Morgan, who proved that the carriers of hereditary factors are chromosomes.

Rice. 1. Drosophila is the most popular object of genetic research: a - male; b - female

American biologist, one of the founders of genetics and the chromosome theory of heredity. Laureate of the Nobel Prize in Physiology or Medicine for 1933 with the wording: "For discoveries related to the role of chromosomes in heredity."

Since 1910 Thomas Morgan studied the inheritance of mutations in the Drosophila fly.

(Drosophila is a convenient model to study, since it is cheap, has only 4 pairs of chromosomes, and begins to reproduce 12 days after its appearance, producing offspring of 1000 individuals).

“To comprehend the more complex mysteries of heredity, it was necessary to find a more convenient object of study than peas or violets. He was found in 1907 by an American Thomas Morgan in the face of a small fruit fly - Drosophila. In the cells of her salivary glands, 4 very large chromosomes are visible: they are easy to see even with a magnifying glass , so that it is possible to associate changes in the appearance of chromosomes (gene variations) with changes in the appearance of the insect itself by variations of the phenotype. From 1907 to 1926, Morgan and his students monitored the heredity of Drosophila - fortunately, it turned out to be as multifaceted and unstable as the heredity of dogs. Morgan was able to distinguish hundreds of variations in the appearance of fruit flies and to compile an Atlas of the location of the corresponding genes in the chromosomes of the fruit fly. "

Smirnov S.G., Lectures on the history of science, M., Publishing house of MCNMO, 2012, p. 126.

“The American has done a tremendous amount for the development of the doctrine of heredity Thomas Morgan who at first was an equally ardent opponent Mendel and decided to refute it on another object - rabbits. However, the trustees of Columbia University, where Morgan worked, found the rabbits too expensive; Morgan did not lose heart and used for experiments a tiny fruit fly - Drosophila.
Drosophila has become a classic object of genetics - the rarest case when the avarice of the suppliers rendered science an invaluable service!
The fact is that in a year you can get 25 generations of fruit flies and place their herds of many thousands on one laboratory table. "

Mednikov B.M., Darwinism in the XX century, M., " Soviet Russia", 1975, p. 25.

The effects discovered by Thomas Morgan with his students: G. J. Möller and A. G. Sturtevant explained the mechanism of action of Gregor Mendel's laws.

In 1920 Thomas Morgan wrote: " Mendel left his conclusions in the form of two basic laws: the so-called law of splitting and the law of independent combination of genes. These laws are based on digital data; they are, therefore, quantitative laws and, if desired, can be represented in the form of a mathematical formula. But, despite the fact that their wording is completely accurate, they are still not give an explanation of how the phenomena controlled by them are carried out in a living organism. An exclusively mathematical interpretation of the principles of splitting and independent distribution of genes could hardly satisfy botanists and zoologists for a long time. Inevitably, there should have been a desire to determine where, when and how the process of splitting and reunification is carried out, and inevitably there should have been an attempt to reconcile these phenomena with the amazing processes in the germ cells, which are so widespread. "

Thomas Morgan, Structural Foundations of Heredity, cited in: A Life of Science. Anthology of introductions to the classics of natural science / Comp .: S.P. Kapitsa, M., "Science", 1973, p. 319.

“After a series of lengthy experiments, Morgan and his colleagues at Columbia University came to the conclusion that chromosomes are indeed directly related to heredity. The results of some of Morgan's experiments seemed to contradict Mendelian law of independent inheritance, according to which every organism has genes that control one trait or another, and the inheritance of one trait does not depend on the inheritance of another.
The group, led by Morgan, found that some of the signs, apparently, are still related. In other words, their combination occurs in offspring more often than Mendel's statistical laws suggest. Morgan called this phenomenon floor adhesion. The linkage tendency suggested to Morgan that genes appear to be located in close proximity to each other on the same chromosome.
However, Morgan and his collaborators noted that genes located on the same chromosome were inherited together less frequently than might be expected. Then Morgan began to suspect that the chromosomes in the pair could split and exchange sections, thereby allowing the exchange of genes. This idea was confirmed by the data obtained under the microscope of intertwining chromosomes. It turns out that the greater the distance between two genes on the same chromosome, the more likely it is to break. If this is the case, then the genes will not be inherited together. Conversely, genes that are close to each other on the chromosome are less likely to be separated. Based on this principle, Morgan and his colleagues drew up "maps" showing the relative position of genes in the chromosomes of the fruit fly. The idea that genes are localized in a chromosome in a specific linear sequence can be considered one of the main achievements of genetic theory. "

Larina OV, Gitun TV, Nobel Prize winners, "House of Slavic Books", 2006, p. 372-373.

"Morgan's research was closed the question of the possibility of "education" of certain properties in a breed or variety with subsequent transfer to descendants. The only way in which genes can acquire new characteristics has been called mutation.
Accidental and uncontrolled mutations as the only mechanism of evolutionary development were perceived by critics - philosophers and religious leaders - as an open and senseless deception of the forces of nature, bringing man down one more step on the ladder leading from heaven. But Morgan was not involved in this debate.
In addition, he realized that genetics provided more complete knowledge than eugenics, and left the ranks of this movement in 1914.
Chromosome theory heredity won an increasing number of supporters. In 1933, Morgan received the highest award for a scientist - the Nobel Prize - for discoveries in the field of physiology and medicine. But in the USSR not accepted this theory. The country's leaders did not want to come to terms with the fact that some areas human nature they are not under their control. "

Travina E., Thomas Morgan: a miracle about bread, Sat: Revolt of the masses, St. Petersburg, "Midgard", 2005, p. 187.

From 1904 to 1928 he was professor of experimental zoology at Columbia University (New York), and from 1928 to 1945 he was professor of biology and laboratory director at the California Institute of Technology (Pasadena). In the last years of his life he acquired a small laboratory in Corona del Mar (California).

In one of his early works, Morgan criticizes Mendelian theory of heredity. He believed that chromosomes are not carriers of heredity, but are products of early stages of development. He also did not support Darwin's idea of "gradual change", preferring the version of the Dutch botanist Hugo de Vries that the emergence of a new species is the result of mutations.

In 1900, the focus of geneticists around the world was Mendel's work on the inheritance of traits in peas. In these works, Mendel argued that traits are inherited, obeying strict mathematical laws.

In 1902, the biologist W. Sutton suggested that heredity units (genes) are located inside or on the surface of structures of the cell nucleus, called chromosomes.

Morgan disagreed with this, believing that chromosomes are products of an early stage in the development of an organism.

In 1909, Morgan began working with the fruit fly Drosophila.

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Very soon (in 1909) the first mutations appeared. Subsequent study of this phenomenon ultimately allowed the scientist to establish the exact location of genes and how they work. One of the most important discoveries can be considered the "dependence" of certain mutations on sex (Morgan called this phenomenon "linkage" of genes): white eyes in fruit flies were transmitted only to males. After processing a large amount of information, Morgan came to an interesting conclusion: genes located on the same chromosome were inherited together much less often than one might expect. Therefore, chromosome splitting and the exchange of genetic material between chromosomes are possible. The further apart genes are located on a chromosome, the higher the likelihood of their rupture. On the basis of this, Morgan and his colleagues compiled "maps" of the chromosomes of Drosophila. His conjecture about the "linear" arrangement of genes in the chromosome, and that the "linkage" of genes depends on the distance of one gene from another, is one of the revolutionary discoveries in genetics.

Major works: Regeneration. N-Y: Macmillan, 1901; Heredity and Sex. N-Y: Columbia Univ. Press, 1913; The Theory of the Gene. New Haven, CT: Yale Univ. Press, 1932; The Scientific Basis of Evolution. London: Faber and Faber, 1932.

(1866 - 1945)

American medical scientist Thomas Morgan was born on September 25, 1866 in Lexington (Kentucky). He was the eldest son and the first of three children of diplomat Charlton Hunt Morgan and Helen (Key-Howard) Morgan (her grandfather is American composer F.S. Key - author of the US national anthem).

From childhood, the boy was interested in natural history and the exact sciences, collected a collection of different species of birds. Over time, he worked on the expedition of the US Geological Survey, conducted geological and biological searches in the Kentucky mountains.

1886 Thomas Hunt Morgan received his BS in State College state of Kentucky, he was currently especially attracted by the evolution of species, because then there was little scientific data on the actual mechanism of heredity.

1887 he entered Johns Hopkins University, where he studied animal morphology and physiology. Three years later, he received his Ph.D. for research in the embryology of sea spiders, and in 1891 he became an associate professor of biology at Bryn Mairovsky College. 1901 he published the first scientific work- "Regeneration" - about the relationship between the phenomena of regeneration and early embryonic development organism.

1904 Thomas Morgan is appointed Professor of Experimental Zoology at Columbia University. His own scientific gift inclines him to study the problems of barely nascent genetics, the results of G. Mendel's research on the hereditary traits of beans aroused particular interest.

In the same year, Thomas Morgan married Lillian Vaughan Sempson, a cytologist by profession, they had four children.

1908 Thomas Morgan experiments with the fruit fly Drosophila melanogaster, which has only four chromosomes. Numerous experiments made it possible to state the direct dependence of chromosomes and heredity.

At the beginning of 1912, A.H. Stertevan and K.B. Bridges, then still students of Columbia University, joined the group of researchers. A team of scientists came to the conclusion that chromosomes in a pair can split and recombine, thereby facilitating the exchange of genes, and the greater the distance between two genes in one chromosome, the more likely it is to fail in the process.

1928 Thomas Morgan drops out of Columbia College and immerses himself in the establishment of a biological department at the California Institute of Technology (Caltech) in Pasadena, renowned for experimental biology.

Thomas Morgan received the 1933 Nobel Prize in Physiology or Medicine "for his discoveries related to the determination of the role of chromosomes in the heredity of an organism."

After receiving the Nobel Prize, Thomas Hunt Morgan continued administrative activities to Caltech, combining it with the study of biological regeneration in pigeons, salamanders and the rarest species of mice.

Morgan was a very generous person in life and often financed the training of especially gifted students.

1941 Thomas Morgan is named Distinguished Professor of Biology at Caltech.