Weisman August Biography

In a set of theories, there was a place as an inaccessible person of the gods and the relationship of the level of spiritual development of man with his physical existence, and the advanced - at the time of his creation - scientific research. August Weisman is an outstanding German biologist and philosopher, whose research in the development of organic tissues and cell theory had a huge impact on the development of biology and medicine.

He was among the first to put forward a working theory that explains the process of aging of any living organism and largely influenced the development of such a science as genetics. It is considered one of the founders of modern biology. Weisman received the usual education for that time, including music and drawing lessons. Parents read a legal career for him, since in the Weisman family, jurisprudence was considered a hereditary matter, but the boy liked to study the world around, which was supported by a music teacher who was engaged in collecting butterflies.

Augustus liked this hobby, and in his school years he collected moths, bugs and plants around Frankfurt, spent a lot of time, studying patterns and the coloring of butterfly wings and observing the development of insects from caterpillars into adults. Years will pass, and these observations will form the basis of one of its first books. Friedrich Völer parents could not reconcile with the fascination of August for a long time, but he flatly refused to engage in legal sciences.

A compromise was found: a family friend, chemist Frederick Völer advised the young man to follow in his footsteps - to study medicine. After graduating from the gymnasium, Augustus entered the University of Gettingen, and then worked as a doctor for several years. At first he lived in Rostok, and later opened practice in his hometown. He participated in the Austro-Italo-French war of the year.

But the hobby of biology did not leave him, and Augusta spent every free minute after a microscope. He took up zoology, trained for two months at the biologist R. Leikakhta Gisen University, and A. Joffrue St. Iler Paris University. After that, he decided to devote himself to zoology and was engaged in microscopic research in the field of morphology and embryology. Weisman received a doctoral degree in the year for the work "The influence of light on the movement of zoospores of mushrooms." Since the year, he is Privat-toocent, in the professor of the University of Freiburg, the director of the Zoological Institute.

At that time, the whole scientific world was impressed by the works of Charles Darwin. Therefore, Weisman began by deciding to verify the correctness of his theory with biological methods. He began to study the features of the propagation of the simplest animals - hydr and daphnia, in order to confirm the provisions of evolution formulated by Darwin by example. Professor of Zoology August Weisman devoted most of his life to research in the field of cytology, which is understandable: in the second half of the XIX century.

Already in the first works, Weisman made a major discovery - he described the so -called histolesis - building an adult insect from the cells of its destroyed larva. Weisman is considered the founder of neo -Darwinism, who significantly deepened the foundations of the theory of Ch. In the time of Darwin and much later, scientists believed that the signs acquired during his lifetime were inherited.

Even Darwin, following the general conviction, admitted this, although with great reluctance: he understood that the meaning of natural selection was in this way and a return back to the teachings of Zh. Weisman wondered which no one thought over to him: who proved the inheritance of the acquired signs? What if this apparent evidence is only a delusion, like the observed movement of the Sun on the heavenly vault?

However, at that time, at that time he was 30 years old his vision worsened, and Weisman could hardly work with a microscope. In this he was helped by students, assistants and Mary's wife. But in the year, doctors forbade him to engage in microscopy. To help the scientist, his friends achieved a long vacation, Weisman was given the right to engage only in scientific work and not give lectures at the university.

Only two years later, Weisman was able to resume systematic work behind a microscope. But the new exacerbation of the disease of the eyes forces him to stop working behind a microscope. Now doctors are afraid for his vision so seriously that they recommend not to return to work associated with overwhelming eye voltage. Therefore, the second half of his life Weisman was mainly engaged in the theoretical problems of biology.

In the year, he married Mary Dorothea Gruber. Their son, Julius Weismann - was a composer. The cellular structure of plants and living organisms has long been a secret for anyone. To the city, she not only confirmed the cellular structure of animals and plants. Schleiden and Schwann stated: growth and development are inconceivable without the occurrence of new cells, and the structure of plant cells, bacteria, animals is very similar.

A few years earlier, the British botanist Robert Brown - GG. He is the discoverer of the Brownian movement. Rudolph Virkhov - Gg. Weisman was most interested in chromosomes in the cage.The behavior of chromosomes when dividing cells prompted Weisman to think that they were a material substrate of heredity, transmitting from cage to cage, from generation to generation.

Weeman noted that even in cases where the size and shape of the chromosomes in different cells of the body change, in the germ cells, from which the germ cells are formed, the chromosomes are stable. This provides, according to Weisman, the transfer of hereditary properties from parents to descendants. It was these his works that are now most famous, although he himself did not consider them essential.

Since the end of the 10ths, he moved mainly to theoretical research on the protection, substantiation and development of the teachings of Ch. Standing in the positions of materialism, Weisman defended a mechanistic understanding of life phenomena. Speaking against vitalism, he rejected lamarkism, which recognized the initially appropriate response of living creatures to the influence of the environment and the inheritance of changes that have arisen in this way.

Weisman rightly argued that the issue of inheritance of acquired features can be resolved only with the help of experience, and experimentally showed the inadplicability of mechanical damage. Weisman is the author of speculative theories of heredity and individual development, incorrect in detail, but in principle anticipated modern ideas about the discretion of carriers of hereditary information and their connection with chromosomes, as well as a concept about the role of hereditary inclinations in individual development.

In the years, the evolutionary teaching created by Weisman, called by him neo -Darwinism, followers of T. Lysenko was declared in the USSR Anti -scientific and reactionary August Weisman, which initially shared the idea of ​​Lamarck about the inheritance of acquired signs, subsequently became a decisive enemy, having described the change in his views: “How can the germinal cell lying inside the body be reported, the changes that occurred in the muscles due to its exercise, or a decrease experienced by the body from impending, and moreover It is also to be reported so that later, when this cell grows into a new organism, it has made the same changes that parents have as a result of consumption or non -exposure on the corresponding muscle and on the appropriate part of the body?

Here is the question that has stood before me for a long time and which, according to its further pondering, led me to the complete denial of such a hereditary transfer of the acquired properties. ” Weisman proposed for consideration two options for transmitting body changes to the germ cells: “Either pre -conductive pathways along which germ cells reaches a completely incomprehensible effect, or separation from the changed body of material particles taking part in the construction of the germ plasma; The third is not given.

" Darwin formulated the idea of ​​inheritance of acquired signs as follows: “We can be confident in this in some cases, when all or almost all individuals who are in similar conditions change the same and moreover in a certain way, which we gave several examples. However, it is unclear why descendants should change if their parents fall into new conditions, and why in most cases it is necessary that several generations are in these conditions.

” It was not easy to confirm your confidence in the scientist. To do this, it creates a general theory of gemmulas - elements of the cells that are produced by them, are carried with the flow of blood throughout the body and can develop into cells identical to them. It was assumed that with the help of gemmula changes in a particular organism caused by environmental conditions or exercises, but there was no explanation of how these changes are “preserved” in the structure of the cells.

Weisman enthusiastically spoke about the works of Charles Darwin, although he allowed himself to disagree with some provisions of his theory. So, he did not like it, although not immediately that Darwin supported the Lamarkist hypothesis that acquired signs could be inherited. He first described these views in the essay, presented during the solemn speech on the occasion of taking office as vice -rector of the University of Freiburg.

Weisman considered a “fantastic” assumption that each body of the body is connected by a nerve with each germ cell. The assumption accepted by C. Darwin that each body of the body separates specific gemmulas gathering in the germ cells, Weisman also considered incredible. Experienced way to prove the fallacy of the inheritance of the acquired signs was also tried by Darwin’s cousin, Francis Galton, overflowing the blood of dark rabbits with the bright, and Weisman himself, who experimented with mice.

Weeman is considered the founder of neo -Darwinism, who significantly deepened the foundation of the theory of C. Weisman set a simple experience - he cut off his tails from five generations, "and yet [offspring] did not have a single example of a shortened tail or any other deviation in the structure of this organ." Without insisting on the purity and fullness of the experiment, Weisman saw his task in refuting rumors that existed at that time, for example, about a cat born without a tail due to the fact that many of her relatives lost their own.

It is quite clear why - after all, the chromosomes in the cells of the germinal path, giving the beginning of eggs and sperm from which the new generation will arise, remained unchanged. If you change the embryo cells in any way, as Weisman said, then heredity will change. Weisman recognized the Darwin natural selection as the main lever of evolution, but only in relation to the germinal plasma.

This direction is in genetics the name of Weismanism or Neo -Darwinism. Weisman’s merits in the area of ​​the initiator of genetic theories relate mainly to his experimental studies over the development of various species of animals. Weisman proved that the transition of parental properties for offspring depends on the direct transfer by parents of a certain material substance that affects all the development of offspring.

According to Weisman, this substance is enclosed in chromosomes and chromothynes. Many of Weisman's theoretical provisions could not withstand the test of time. But his main ideas are still the basis of modern genetics and theory of evolution.

In return, Hemmul Weisman created the theory of the germinal plasma, "such a long crawling root, from which individual plants - individuals of consecutive generations periodically rise." Part of this plasma is transmitted from one generation to another and is involved in the construction of organisms. Observations of the development cycle led him to the hypothesis of the continuity of the existence of german plasma.

The scientist saw in it cytological arguments in favor of the impossibility of inheritance of acquired features. Weisman’s conclusion influenced the further development of the theory of evolution and Darwinism. He also made a number of fundamental observations. In Weisman theory, useful features were inherited not because of changes in one organism, but only because of the natural selection: “Everywhere where in free nature the organ intensifies due to use, this organ has a known meaning for the life of the individual; And since this is so, natural selection strengthens it and selects for further reproduction only those individuals in which the body is best expressed ...

The strengthening of the organ in a series of generations depends, thus, not on the summation of the results of use during an individual life, but on the summation of favorable inclinations of the embryo. ” Its main merit is that he emphasized the sharp difference between the inherited signs and signs of beneficial, which, according to Weisman, are not at all transmitted by inheritance.

He was the first to whom the general biological significance of mitosis and the fundamental role of the chromosomal apparatus when cell division were clear. Almost a scientist indicated a new direction of research in the evolution of animals. Another direction of Weisman’s “denials” refers to vitalism - the idea that living organisms have a certain “vital force”, which qualitatively distinguishes them from objects of inanimate nature and makes unproved laws of physics or chemistry.

But in defense of this theory, the great Louis Pasteur put experiments! The grave of August Weisman is the most significant argument in the refutation of the idea of ​​vitalism belongs to Friedrich Völer, who synthesized urea from the inorganic components, to that friend of the Weisman family. His experience was “a great tragedy in science - killing a beautiful hypothesis with an ugly fact,” he wrote later.