Scientists who made discoveries in Morgan genetics. Biography. be born at the right time

(1866-1945) American biologist, one of the founders of genetics

Thomas Morgan was born in 1866 in Leksinpton (Kentucky). At the age of twenty he graduated from the university home state, and after 5 years, John Hopkins University in Baltimore. He immediately became a college professor at Bryn Mawr, from 1904 to 1928 he worked as a professor at Columbia University, and from 1928 to the end of his life he headed a laboratory at the California Institute of Technology.

Although the first step towards solving the problem of heredity was taken by Mendel, when he discovered mathematically correct laws for the transfer of individual properties of an organism to offspring, the development of the science of heredity is still associated with the name of Morgan, because it was he who experimentally substantiated the chromosome theory of heredity.

Morgan and his staff, starting in 1910, in about 15 years received irrefutable evidence the fact that genes are linearly located on chromosomes; established the facts of gene linkage, that is, their joint inheritance in the case of localization on the same chromosome; discovered the principle of independent divergence of each of a pair of chromosomes into daughter cells, including germ cells.

Luck accompanied the scientist in his research, largely because he was able to find for his experiments Living being, able to multiply rapidly in a limited space and does not require large maintenance costs. These conditions were fully met by the well-known and widespread fertile Drosophila fly. In order to find out what signs of the parents the descendants inherited, they were euthanized. Now nothing prevented you from seeing under a magnifying glass what color the eyes of the flies, the back, what shape the wings or abdomen are. When the flies woke up, new generations were received from them and the inheritance of traits was monitored further. Comparing the number of traits that are inherited together with each other, Morgan found that each Drosophila chromosome contains a group of genes linked to each other. So it was found that the genes are really located on the chromosomes. :

Morgan's merits are not limited to this alone. The scientist found numerous deviations from the rule "one chromosome - one group of co-inherited traits." Often, traits that were known to be determined by genes belonging to one group ended up in subsequent generations in a new, unusual for themselves “company” of other traits. To explain this “disorder”, Morgan made a conclusion that was completely innovative for that time: the chromosomes of one pair are capable of exchanging parts with each other. Observations of the behavior of Drosophila chromosomes under a microscope confirmed that at a certain stage of meiosis, two chromosomes approach each other, cross and exchange fragments. This phenomenon is known in science as chromosome crossing, or crossing over.

Morgan and his colleagues imagined chromosomes as necklaces, on which beads - genes - are ordered. This seemingly primitive scheme, especially from the height of our current knowledge, turned out to be very productive. The relative distance between genes on a chromosome began to be determined by simply counting the frequency of "crossover flies". This is the name of the fly offspring with signs, the appearance of which can only be explained by the exchange of the corresponding sections between the chromosomes of one pair. These calculations formed the basis for the construction of the first genetic charts. relative position on the chromosome of individual genes.

By the early 1920s, American scientists had discovered and localized hundreds of Drosophila genes on chromosomes. About 7,000 genes are now known in this fly, distributed over four chromosomes. The principles discovered by Morgan formed the basis for the compilation of genetic maps in all animal organisms.

For his work on the study of heredity, Thomas Morgan was awarded the Nobel Prize in 1933. For a number of years he was president of the US National Academy of Sciences, and in 1932 he became an honorary member of the USSR Academy of Sciences.

The biography of the great American geneticist Thomas Morgan reflects the main milestones of his life and research achievements, which made it possible to successfully develop molecular biology for many years.

The American scientist Thomas Morgan is rightfully considered one of the greatest biologists who made great discoveries for all mankind. He achieved outstanding success in the study of chromosomes and genes, which put molecular biology on a fundamentally new level and made it possible to resort to experimental methods research in genetics.

Thanks to him and Gregor Mendel, subsequent successful work was carried out on the decoding of the genome, in the field of transgenic selection and genetic engineering.

be born at the right time

In Morgan's biography you will not find facts of persecution for his beliefs, non-sharing of views by colleagues or oblivion to certain stage life path. It was a long and happy life, always close to close and dear people, a successful career as a teacher and researcher, who is still considered a genius of fundamental genetics. Representatives of this science even today more often receive Nobel Prize relative to researchers in other fields. At the beginning of the 20th century, thanks to the work of Morgan and colleagues, important genetic data were accumulated, the results of a study of the mechanism of cell division (meiosis and mitosis) appeared, and conclusions were drawn about the role of chromosomes and the cell nucleus in the inheritance of traits.

So, the chromosome theory made it clear the cause of the appearance of hereditary diseases in humans and made it possible to change experimentally hereditary information, becoming the starting point for modern genetic research. Although he was not a discoverer, he managed to formulate the postulates of a theory that changed the whole world. In fact, after Morgan's developments, topics such as life extension, the cultivation of new organs, human transformations remain only a matter of time in modern reality.

Aristocratic background

Thomas Morgan, born in the United States on September 25, 1866, is the nephew of Gent Morgan, a prominent Confederate army commander, and the son of Hunt Morgan, the American consul in Sicily and a successful diplomat. The maternal grandfather of the scientist was the author of the national anthem of America. From childhood, the boy was drawn to such sciences as geology and biology, and at the age of 10 he was fond of searching for unusual stones, studying bird eggs and feathers. Having matured a little, Thomas helped the members of the expeditions of the US Geological Survey in his native places. And at the age of 20, he receives a bachelor's degree after graduating from college.

student time

At the university, a young man devotes a lot of time to the physiology and morphology of animals. First scientific work dealt with the physiology and structure of sea spiders. Then came the turn of embryology. The young scientist becomes a master, defends his thesis and heads the biological department of Bryn-Mair College. This is followed by an internship at the Naples Zoological Laboratory in 1894 and the beginning of research on hereditary traits.

At that time, there was a very topical controversy between preformists, who were confident in the presence of structures in gametes that determine the development of an organism, and epigenists, who argued that external factors influence the formation of an organism. At the same time, Morgan stands in the middle between the positions. In 1895, Thomas became a professor and soon published two books: Development of the Frog's Egg and Regeneration. Evolution and heredity still remain the priority directions of his activity. The scientist enters into marriage in 1904 with Lillian Vaughan Sampson, his student, who not only gave birth to four children, but also became a reliable assistant in research.

Columbia University

Working at the university since 1903 at the Department of Experimental Zoology, in 24 years Thomas Morgan manages to make the most significant discoveries in the history of inheritance and evolution. Researchers of that time were looking for confirmation of Mendel's theory regarding natural selection, and Morgan, at the age of 43, personally checks the correctness of a colleague's research. As a result successful work he acquires the title of "lord of the flies" for many years. As an object of experiments, he chooses fruit flies, which become the "sacred cow" of geneticists for the whole coming century.

Most importantly, these flies have only 4 chromosomes, which are easy to study throughout the entire 3 months of Drosophila's life. The successful experiments of the scientist Thomas Morgan were helped by his talented students, who took an active part in the organization of laboratory No. 213 - the legendary "fly room" within the walls of Columbia University.

Innovation in teaching

That same Colombian laboratory, famous all over the world, has become a place for an introductory visit for many famous scientists. Thanks to this small room of only 24 square meters, the organization of the educational process. Morgan based his work on the principles of democracy, lack of subordination, free exchange of opinions, collective brainstorming, and complete transparency. His methodology became the basis for teachers of American universities, and then European ones.

For a long two years, Morgan and his colleagues have been struggling almost to no avail to resolve the issues of inheritance of mutations. However, then a real miracle happens - flies with altered traits are born, which subsequently made it possible to formulate the theory of inheritance. Crossing individuals, counting thousands of offspring, thousands of bottles of fruit flies - all this was the price of the scientist's success. Evidence has been obtained for sex-linked inheritance and storage of trait data at a particular site on the chromosome. The results were framed in a paper titled "Sex-Linked Inheritance".

Chromosomal theory

The successful result of all the activities of Thomas Morgan is the substantiation of the theory of inheritance. Its basis - the material basis of heredity are the chromosomes, where the genes are arranged in a linear order. Morgan discovered linked genes that are inherited together, as well as traits that are inherited according to sex.

Achievement recognition

Within a few years, Thomas Morgan became a member of many academies around the world, including the USSR Academy of Sciences in 1923. And 10 years later, the scientist was awarded the high title of Nobel Prize winner for his discoveries in the field of the influence of chromosomes on heredity. Morgan shared the award with colleagues Startevan and Bridges. In the collection of the great scientist, the Darwin Medal donated in 1924, in 1939 - the Copley medal, the Faculty of Biology in Kentucky is named after him, as well as the award of the Society of Geneticists of America, which takes place annually. In addition, in genetics there is the concept of a morganide - a unit of gene linkage. From 1928, he directed the Kirchhoff Laboratory at the California Institute of Technology for many years. The cause of death of the scientist in 1945 was gastric bleeding.

As a conclusion

Of course, Thomas Morgan made an invaluable contribution to biology, which is comparable to the first flight into space or the discovery atomic nucleus in physics. It was noble and good person with a good sense of humor, unpretentious in everyday life and always self-confident. He did not pursue fame, did not dream of becoming a legend, but, on the contrary, he wanted to rid mankind of myths and prejudices. The geneticist was well versed in the subject he studied. Despite all his great discoveries, Thomas Morgan was able to remain just a biologist throughout his life.

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Morgan Thomas Hunt Morgan Thomas Hunt

(Morgan) (1866-1945), American biologist, one of the founders of genetics, foreign corresponding member of the Russian Academy of Sciences (1923) and foreign honorary member of the USSR Academy of Sciences (1932), president of the National Academy of Sciences of the USA (1927-31). Thanks to the work of Morgan and his school (G. J. Möller, A. G. Sturtevant, and others), the main provisions of the chromosome theory of heredity were formulated and experimentally confirmed; regularities of location and linkage of genes in chromosomes, their recombination were established. Morgan's work played an important role in understanding genetic foundations evolution, the role of heredity in individual development and others. Nobel Prize (1933).

MORGAN Thomas Hunt

MORGAN (Morgan) Thomas Hunt (September 25, 1866, Lexington, Kentucky - December 4, 1945, Los Angeles), American biologist, one of the founders of genetics, foreign corresponding member of the Russian Academy of Sciences (1923) and foreign honorary member of the USSR Academy of Sciences (1932) ). President of the US National Academy of Sciences (1927-31). Nobel Prize (1933).
Born into a wealthy family of a diplomat. As a child, he became interested in natural science, had an interest in exact sciences. Graduated in 1886 State College(now the University of Kentucky), receiving a bachelor's degree. In 1890 he received a Ph.D. from Johns Hopkins University for research on the embryology of sea spiders. In 1891-1904 he was a professor at Bryn Mawr College (Pennsylvania) College. In 1904-1928 professor at Columbia University (New York), since 1928 - at the California Institute of Technology.
First scientific works Morgan concerned experimental zoology and embryology. Later, he began a systematic study of heredity, which allowed him to expand Mendel's laws (cm. MENDEL'S LAWS). Based on these laws and on the basis of his own experiments, Morgan developed the chromosome theory (cm. CHROMOSOMAL THEORY OF HEREDITY) heredity, the main provisions of which opened the way for his followers to new research and led to the flourishing of cytogenetics (cm. CYTOGENETICS), i.e. cellular and biochemical genetics. For his work on the study of heredity in 1933, Morgan was awarded the Nobel Prize.
The following works of Morgan are considered the most important: “Regeneration” (1901), “Experimental Zoology”, “Heredity and Sex” (1913), “Critique of the Theory of Evolution”, “ Physical foundations heredity" (1932), "Drosophila fly genetics" (together with Bridges and Sturtevant (cm. STERTEVANT Alfred Henry)), "The Theory of the Gene" (1932).
Morgan was a follower of A. Weisman (cm. WEISMAN August) in the question of the study of the cell, who came to the conclusion about the continuity of the germ plasm, which has signs of heredity and is distinguished by a clearly expressed chemical structure. But he failed to answer the question of what exactly determines the similarity of offspring and parents. Weismann's theory has spread all over the world.
Long and difficult studies of the phenomenon of heredity and variability of species ended in success only after Morgan's experiments with the Drosophila fly. (cm. DROSOPHILA). The scientist developed the theory of genes as carriers of certain hereditary properties, he divided all the studied properties of the fruit fly into four groups, which are inherited and are associated with the presence of four pairs of chromosomes in the fruit fly. Scientists have suggested that combinations of these chromosomes cannot exceed thousands of different genes. Depending on what genes a fly has, it will belong to one species or another. A thousand experiments with Drosophila allowed the Morganists to draw maps that can determine where a particular gene is located on the chromosome, which made it possible to assume that in the chromosomes of all plants and animals, each gene is located in a precisely defined position.
Thus, Morgan substantiated the chromosome theory of heredity; the regularities established by him for the arrangement of genes in chromosomes contributed to the elucidation of the cytological mechanisms of Mendel's laws and the development of the genetic foundations of the theory of natural selection.

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Morgan, Thomas Hunt— Thomas Hunt Morgan. MORGAN Thomas Hunt (1866-1945), American biologist, one of the founders of genetics. President of the US National Academy of Sciences (1927-31). The works of Morgan and his school (G.J. Meller, A.G. Sturtevant, K. Bridges and others) substantiated ... ... Illustrated Encyclopedic Dictionary

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Thomas Hunt Morgan (born Thomas Hunt Morgan, September 25, 1866, Lexington December 4, 1945, Pasadena) is an American biologist, one of the founders of genetics, a foreign corresponding member of the Russian Academy of Sciences (1923) and a foreign honorary member of the USSR Academy of Sciences, ... ... Wikipedia

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- (English Morgan) common English name, often also used as a surname. A Welsh word meaning "of the sea". Initially, the Morgans were from Wales, after they settled throughout the UK ... Wikipedia

Thomas Hunt Morgan - American biologist, one of the founders of genetics, foreign corresponding member of the Russian Academy of Sciences (1923) and foreign honorary member of the USSR Academy of Sciences, president of the National Academy of Sciences of the USA (1927-31), chairman of the Sixth International Congress on Genetics in Ithaca, New York ( 1932). Winner of the Nobel Prize in Physiology or Medicine in 1933 "for discoveries related to the role of chromosomes in heredity."

Thomas Morgan was born September 25, 1866 in Lexington, Kentucky. His father Charlton Gent Morgan, US Consul in Sicily, was a relative of the famous magnate J.P. Morgana, mother - Ellen Kay Morgan. He was the eldest son and first of three children of diplomat Charlton Hunt Morgan and Helen (Key-Howard) Morgan (her grandfather was the American composer Francis Scott Key - author of the US national anthem).

From childhood, Thomas showed an interest in natural science and the exact sciences, collected a collection of different types birds. In 1886, Thomas Morgan graduated from Kentucky State College with a bachelor's degree, he was now particularly attracted to the evolution of species, because then there was little scientific data on the actual mechanism of heredity. In the summer immediately after graduation, he went to the naval station at Ennisquam on the Atlantic coast, north of Boston. Over time, he worked on the expedition of the US Geological Survey, conducted geological and biological searches in the mountains of Kentucky.

IN 1887 Morgan entered Johns Hopkins University where he studied animal morphology and physiology. And in 1890 (Three years later) he received a Ph.D. for research on the embryology of sea spiders and in the same year - an Adam Bruce scholarship, which allowed him to go 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. In the summer immediately after graduation, he went to the naval station at Ennisquam on the Atlantic coast, north of Boston. This was Last year the existence of a local laboratory. The following year, the group that organized and ran this laboratory came to Woods Hole. In Ennisquam, Thomas was first introduced to marine life. This acquaintance captured him, and from then on the study of marine forms attracted his special interest throughout his life. My thesis he did under the direction of William Keith Brooks, a marine biologist. Brooks was an excellent teacher who trained a whole generation of eminent American zoologists.

IN 1888 In the same year, Morgan moved to Woods Hole, and in the summer of the same year he began working at the State Fishing Station.

IN 1889 worked as a research fellow at the American Fisheries Committee.

IN 1890 received his doctorate from Johns Hopkins University and in the same year - the Adam Bruce Scholarship, which allowed him to go 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. In one of his early works, Morgan criticizes the Mendelian theory of heredity. He believed that chromosomes are not carriers of heredity, but are products of the early stages of development. He also did not support Darwin's idea of "gradual change", preferring the version of the Dutch botanist Hugh de Vries that the emergence of a new species is the result of mutations. At that time, almost nothing was known about the mechanism of inheritance, and the methodology for studying the process of evolution and heredity consisted in comparing the morphology and physiology of representatives of different species. Based on the data obtained, scientists tried to draw conclusions about the reasons for the similarity or difference between existing species. Morgan was no exception, his first work on the study of heredity was carried out in accordance with generally accepted methods.

TO 1891 he completely mastered the comparative and descriptive methods of research, but they did not give answers to his questions, and he turned to experiments, hoping to get a specific result. In 1891, Thomas Morgan began work as an adjunct professor of biology at Bryn Maire Women's College.

IN 1897 In the year he was elected one of the trustees of the sea station, and he remained so all his life. That was the year the station and its administration were taken over by the Young Turks, and Morgan was one of the new trustees chosen at this critical period. At the same time, Wilson from the University of Chicago appeared at the station.

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

IN 1901 Morgan's first fundamental work, "Regeneration", was published in 1994, devoted to the relationship between the phenomena of regeneration and the early embryonic development of the organism. Back in 1900-1901, CW Woodworth studied Drosophila as an experimental material and was the first to suggest that Drosophila can 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 produces offspring of 1000 individuals. It is easy to learn during a lifetime, which is only 3 months long. Plus, it costs next to nothing. W. E. Castle and F. E. Lutz also worked with Drosophila, who suggested that Morgan work with the fruit fly.

IN 1902 biologist W. Sutton suggested that the units of heredity (genes) are located inside or on the surface of the structures of the cell nucleus, called chromosomes. Morgan did not agree with this, believing that chromosomes are products of an early stage in the development of an organism. He preferred the idea expressed by the Dutchman Hugo de Vries that the new kind formed as a result of mutations. In order to confirm this hypothesis, Thomas Morgan began to look for a convenient object for research. He needed an unpretentious animal with a fast life cycle.

Wilson in 1904 convinced Thomas Morgan to take the chair of experimental zoology at Columbia University. For twenty-four years they worked in very close association. Like most zoologists of his time, Morgan was educated in comparative anatomy and especially descriptive embryology. His dissertation dealt with the embryology of a species of sea spider and was based on material he collected at Woods Hole. This work was based on descriptive embryological data with conclusions extending into the realm of phylogeny. His own scientific gift inclines him to study the problems of barely nascent genetics, of particular interest were the results of G. Mendel's research on the hereditary characteristics of beans. The problems that Morgan and other embryologists were then working to solve concerned the extent to which development depends on or is influenced by specific formative substances supposedly present in the egg. How are these formative substances involved in development and how do they function? The young scientist was also engaged in physiological research, but genetics brought him real fame.

In the same year, Thomas Morgan married Lillian Vaughan Sempson, a cytologist by profession, to his student from Bryn Mair. They had four children.

FROM 1904 to 1928 He was Professor of Experimental Zoology at Columbia University (New York). When the results of August Weisman became known, who found out that hereditary qualities are transmitted using chromosomes, scientists remembered another scientist, Mendel, who had shown earlier that heredity is transmitted by genes. At first, Thomas Morgan was skeptical of the theories that claimed that chromosomes are the carriers of heredity. In the same way, Morgan did not accept the Darwinian hypothesis of the accumulation of gradual changes.

At the end of the 11th century, Morgan visited the garden of Hugh de Vries in Amsterdam, where he saw the defriz lines of evening primrose. It was then that he showed his first interest in mutations. Whitman, director of the Woods Hole Biological Station, who was an experimental geneticist, also played a role in Morgan's reorientation. He devoted many years to the study of hybrids between different species of doves and pigeons, but did not want to apply the Mendelian approach. This is understandable, since the pigeons in this case get, to put it mildly, a hodgepodge. Strange signs that do not give a beautiful ratio of 3: 1 confused Morgan, and for the time being, he did not see a way out. Thus Morgan, rather, could be considered an anti-Mendelist.

1908 d. Having started his experiments, Morgan first obtained fruit flies in grocers and fruit shops, the benefactors of the shopkeepers, who were annoyed by the flies, willingly allowed the eccentric to catch them. Thomas Morgan experiments with the fruit fly Drosophila melanogaster, which has only four chromosomes. Numerous experiments made it possible to establish a direct relationship between chromosomes and heredity.

IN 1909 Morgan began working with the Drosophila fruit fly. Very soon (in 1909) the first mutations appeared. The subsequent study of this phenomenon eventually allowed the scientist to establish the exact location of the 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. Having processed a large number of information, Morgan came to interesting conclusions: genes located on the same chromosome were inherited together much less often than one might expect. Therefore, splitting of chromosomes and exchange of genetic material between chromosomes and genes is possible. The further apart genes are on a chromosome, the more likely they are to break. Based on this, Morgan and colleagues compiled "maps" of Drosophila chromosomes. His guess about the "linear" arrangement of genes in the chromosome, and that the "linkage" of genes depends on the remoteness of one gene from another, is one of the revolutionary discoveries in genetics.

Morgan's fly-room at Columbia University has become legendary. It was a thirty-five room square meters, which housed eight workplaces. They also cooked food for flies. There were usually at least five workers in the room. In many jars and bottles, myriads of flies hatched from larvae and gave themselves to science. There were never enough bottles, and according to the story, in the early morning on the way to the laboratory, Morgan and his students stole milk bottles that Manhattan residents put out the door in the evening. With his light hand they have become a favorite object of genetic research in hundreds of laboratories. They are easy to get, they are found everywhere, they feed on plant sap, any fruit rot, and the larvae absorb bacteria. The breeding energy of Drosophila is huge: from an egg to an adult, it takes ten days. For geneticists, it is also important that Drosophila are subject to frequent hereditary changes; they have few chromosomes (only four pairs), the cells of the salivary glands of fly larvae contain giant chromosomes, they are especially convenient for research.

Growing flies in glass jars and observing them under a microscope, Morgan discovered the appearance of, in addition to the usual red-eyed flies, white-eyed, yellow-eyed, and even pink-eyed flies. Over ten years, many different mutants have been discovered in Drosophila. Morgan crossed flies while following huge amount signs: eye color, body color, unequal number of bristles, various shapes and sizes of wings.

It is now clear that Morgan's experimental technique was simply not suitable for detecting the increase in mutation rate that would have occurred under the influence of radium. Nevertheless, the scientist received mutations, began to study them, and everything that followed came from these supposedly spontaneous mutations. The first of these mutations, not the first to be found, but the first to actually have great importance, there was a sign of white eyes, which turned out to be sex-linked. It was a big discovery. Analyzing the results of observations, Thomas Morgan came to the conclusion that a number of qualities are transmitted to descendants in the aggregate. This made it possible to hypothesize that the genes are not scattered throughout the cell, but are linked into certain islands. The fruit fly has only four pairs of chromosomes. Accordingly, Morgan succeeded in dividing the hereditary traits of Drosophila into four groups. He concluded that genes are located on chromosomes. Each chromosome contains hundreds of genes organized into chains. With the help of the fly, genetics has made many discoveries to date. The fame of Drosophila is so great that on English language a yearbook dedicated to her is published, containing abundant and varied information.

FROM 1911 Morgan and his associates began to publish a series of works in which, experimentally, on the basis of numerous experiments with Drosophila, it was proved that genes are material particles that determine hereditary variability, and that the chromosomes of the cell nucleus serve as their carriers. Then the chromosomal the theory of heredity, which confirmed and reinforced the laws discovered by Mendel.

One of the associates of the scientist Alfred Sturtevant recalled: “I am afraid that I will not be able to give an idea of the atmosphere that prevailed in the laboratory. I think it was something that had to be experienced to be fully appreciated. One of the greatest virtues of this place was the presence of both Morgan and Wilson. So students specializing in one of them often saw the other. They complemented each other in a number of ways and were great friends. In our early years at Columbia University, we fed fruit flies bananas, and there was always a big bunch of bananas hanging in the corner of the room. Wilson's room was a few doors down from ours, down the corridor. He was very fond of bananas, so there was another motivating reason to visit the "fly room" often.

Throughout this time, Morgan made regular visits to Woods Hole. This, however, did not mean a break in experiments with fruit flies. All cultures were packed in kegs - large kegs of sugar, and sent by express steamer. What you started in New York, you finished Hole, and vice versa. We always came by water - that was the time when the Fall River Line was in operation, and Morgan was always doing all sorts of experiments that had nothing to do with working on fruit flies. He raised chickens, rats and mice, grew various plants. And it was all carried by hand, and loaded onto the Fall River Line ship, and then brought back to New York. And when Morgan got here, he plunged headlong into working with marine forms, into the embryology of one variety or another, even though work with Drosophila was actively moving forward in the meantime. That was Morgan's style of work - he did not feel happy if he did not forge several things from the hot at the same time.

Morgan came from an aristocratic family, but was devoid of any arrogance or snobbery. When the Russian scientist Nikolai Vavilov came to Morgan, he knew well the work of the Colombian laboratory. It seemed unlikely to Vavilov that genes could be located on a chromosome, like beads on a string, and such an idea seemed to him mechanistic. Vavilov expressed all this to Morgan, expecting sharp, even, perhaps, in an arrogant tone, objections from the world-famous geneticist. Nikolai Ivanovich, of course, could not know the character traits of the famous scientist. After listening carefully to Vavilov, Morgan suddenly said that the idea that the genes are located linearly on the chromosome somehow did not like him. If anyone gets evidence that this is not so, he will readily accept them.

At the beginning 1912 A.H. Stertevan and K.B. Bridges, then students at Columbia University, joined the group of researchers. A team of scientists came to the conclusion that the chromosomes in a pair can split and recombine, thereby facilitating the exchange of genes, moreover, than more distance between two genes on the same chromosome, the more likely the process is to fail. Thomas Morgan showed that the greater the distance between two genes, the greater the likelihood of a chain break. This meant that genes that were far apart could not be inherited together. Conversely, closely related genes are less likely to separate. Professor Thomas Morgan and his colleagues found that the magnitude of the linear distance between genes can characterize the degree of linkage of genes. Morgan's discoveries made it possible to assert that heredity can be described by precise quantitative methods. Based on his theory, Thomas Morgan mapped the location of genes in Drosophila chromosomes.

One of the important discoveries is the “dependence” of certain mutations on sex (Morgan called this phenomenon “linkage” of genes): white eyes in Drosophila were transmitted only to males. This is how the sex chromosomes were discovered. After processing a large amount of information, Morgan came to interesting conclusions: genes located on the same chromosome were inherited together much less often than one might expect.

Morgan published the first article on Drosophila in 1910 year, but in full force his arguments were set forth in 1915 th, when his students - Sturtevant, Bridges and Meller, published the book Mechanisms of Mendelian heredity, in which they announced that heredity obeys quite definite laws, and it can be described by exact quantitative methods. This opened the way to the purposeful construction of new varieties of plants and animal breeds, to a revolution in medicine and agriculture.

Morgan was already under fifty and professional recognition was not long in coming.

IN 1916 Morgan presented a series of lectures at Princeton University, later published as a critic of the theory of evolution, Mendelian theory of heredity and Darwinian theory of natural selection. He formulated a revised version of Darwin's theory of natural selection, which became known as the modern evolutionary synthesis.

IN 1919 he was elected a Foreign Member of the Royal Society of London, in 1924 he was awarded the Darwin Medal; Morgan became a member of the academies of sciences different countries(and also in December 1923 and a member of the Academy of Sciences of the USSR). In the same year, his book is published: The Mechanism of Mendelian Inheritance. In the late 1920s, he headed the US National Academy of Sciences.

1924 year. Morgan was awarded the Darwin Medal, the highest award of the Royal Society of Great Britain. Awarded for outstanding achievements in biology, in the areas in which Charles Darwin worked.

IN 1928 Morgan moved to the California Institute of Technology in order to organize a new biological department. What interested him in this enterprise was the opportunity to organize the department as he wanted, and, moreover, at an institute where physics and chemistry were at their best, where a research atmosphere reigned, and where work with students was aimed at growing researchers out of them. . Morgan remained at the institute until his death, but every summer he returned regularly to Woods Way. For ten years, Morgan's students managed to study three hundred generations of fruit flies.

IN 1932 his book Roles of Mutation, Inbreeding, Crossbreeding and Selection in Evolution is published

IN 1933 Thomas Morgan was awarded the Nobel Prize in Physiology or Medicine for discoveries related to the role of chromosomes in heredity "for 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 his administrative work at Caltech, combining it with the study of biological regeneration in pigeons, salamanders, and rare species of mice. Morgan was a very generous person in life and often financed the education of especially gifted students.

In the thirties, Vavilov wrote: “The laws of Mendel and Morgan formed the basis of modern scientific ideas about heredity, on which selection work is built, both with plant and animal organisms ... Among the biologists of the 20th century, Morgan stands out as a brilliant experimental geneticist, as an explorer of exceptional range."

1941 Mr. Thomas Morgan received an honorary professorship of biology at Caltech.

Morgan liked to tease, he liked to play. One of his scientist friends admitted that he often argued with Morgan, but whenever he began to think that his arguments had prevailed, he suddenly found that, without understanding how this happened, he was arguing from the opposite, losing side. . This is how a brilliant scientist could arrange it. But, on the other hand, Morgan was always friendly, always ready to help, and if you wanted to discuss something with him seriously, whether it was scientific or personal matters, he was always ready to provide support. Morgan's two most abusive words were: "metaphysical" and "mystical." The word "metaphysical" meant for him something connected with philosophical dogma, some kind of explanation, inaccessible to the verification of experience.

In the last years of his life, he acquired a small laboratory in Corona del Mar (California).

American biologist, one of the founders of genetics and the chromosomal theory of heredity. Winner of the Nobel Prize in Physiology or Medicine in 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 object for study, since it is cheap, has only 4 pairs of chromosomes, and begins to reproduce 12 days after its appearance, bringing offspring in 1000 individuals).

“In order to comprehend the more complex secrets of heredity, it was necessary to find a more convenient object of study than peas or violets. It 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 you can link changes appearance chromosomes (gene variations) with changes in the appearance of the insect itself by variations in the Phenotype. From 1907 to 1926, Morgan and his students observed 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 compile an Atlas of the location of the corresponding genes on the fruit fly's chromosomes.

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

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

In 1920 Thomas Morgan wrote: " Mendel left his conclusions in the form of two basic laws: the so-called splitting law and the law of independent combination of genes. These laws are based on digital data; they are thus quantitative laws and, if desired, can be represented in the form mathematical formula. But, despite the fact that their wording is completely accurate, they are still not give explanations 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 must have been a desire to determine where, when and how the process of splitting and reunification takes place, and inevitably there must have been an attempt to reconcile these phenomena with the amazing processes in the germ cells that are so widespread.

Thomas Morgan, The Structural Foundations of Heredity, cited in: A Life of Science. Anthology of introductions to the classics of natural science / Comp.: S.P. Kapitsa, M., "Nauka", 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 Mendel's law of independent inheritance, according to which each 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 signs, obviously, are still related. In other words, their combination occurs in descendants more often than the statistical laws of Mendel suggest. Morgan called this phenomenon floor traction. The linkage tendency suggested to Morgan that the genes seemed 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 less likely to be inherited together than might be expected. Then Morgan began to suspect that the chromosomes in a pair could split and exchange sections, thereby allowing the exchange of genes. This idea was supported by microscopic data on 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 so, then the genes will not be inherited together. Conversely, genes that are close together on a chromosome are less likely to be separated. Based on this principle, Morgan and colleagues made "maps" showing the relative positions of genes on the fruit fly's chromosomes. The idea that genes are located on the chromosome in a specific linear sequence can be attributed to the main achievements of genetic theory.

Larina O.V., Gitun T.V., Nobel Prize winners, House of the Slavic Book, 2006, p. 372-373.

"Morgan's research was closed the question of the possibility of "educating" certain properties in a breed or variety with subsequent transfer to descendants. Mutation has been suggested as the only way genes can acquire new characteristics.
Random and uncontrolled mutations as the only mechanism of evolutionary development were perceived by critics - philosophers and religious figures- as an open and senseless deception of the forces of nature, bringing down a person one more step on the ladder leading from heaven. But Morgan was not included in these debates.
In addition, he realized that genetics provides a more complete knowledge than eugenics, and left the ranks of this movement in 1914.
The chromosome theory of heredity conquered everything more 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 leaders of the country did not want to come to terms with the fact that some areas human nature they are out of control."

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