From Big Medical Encyclopedia

LAMARCKISM — the concept of evolutionary development of wildlife based on idea of transfer by inheritance of the signs acquired by separate individuals in the course of individual devices to environmental changes.

A lamarckism sometimes incorrectly call theory of evolution Ge. Lamarck . However the term «lamarckism» arose only in 60 — the 70th there are 19 century as an antithesis to Darwinism (see) also designated only those views of Ge. Lamarck which contradicted theory of evolution of Ch. Darvin. Identifying change of organisms and evolutionary process, supporters of L. believed that speciation is defined by direct environmental changes, but not natural selection (see).

Obscurity of patterns of variability and heredity in biology of that period was a source of a certain attractiveness of the ideas L. Tak, the nek-ry tribute to lamarkistsky ideas of inheritance of acquired characters was paid by Ch. Darwin in the to «a temporary hypothesis of a pangenesis». During the subsequent discussions between Darwinians and lamarkist these views of Ch. Darvin were emphasized and exaggerated by the last and in some cases in a wrong way were given for a cornerstone of Darwinism.

K L. also some large paleontologists inclined. It was explained by the fact that though fossil material well shows the adaptive nature of variability, nevertheless it is hard to establish its reasons: it is caused by action of natural selection or represents result of inheritance of the signs acquired in the course of individual adaptation.

Attempts to experimentally check a possibility of evolution of organisms by their direct adaptation on the basis of inheritance of acquired characters were made. However the obtained data on a morfogenny role of factors of the environment confirmed only the modification nature of variability of organisms. They did not give proofs of existence of direct adaptation of hereditary character.

At the end of 19 century supporters of L. were divided into various schools, though diverse, but combined by recognition of inheritance of acquired characters and underestimation or denial of an evolutionary role of natural selection. Among these schools which received the general name «neolamarckism» offered by Pakkard (A. Packard, 1901), allocated three main: mekhanolamarkist, ortolamarkist and psikholamarkist.

According to representations of mekhano-lamarkist [Spencer (N. of Spencer), G. Bonnier, etc.], the body (catfish) influences sex cells, causing in them the changes similar to changes of a body that leads to transfer by inheritance of «acquired signs» (so-called somatic induction). Ortolamarkista [Neghelli (To. W. Nageli), H. F. Osborn, L. S. Berg, etc.], trying to explain the fact of an orientation of evolutionary process, considered «internal aspiration to progress» as the reason of development of properties of organisms. So, the largest amer. paleontologist of the end of 19 century. Cop (E. D. Litter) attached great value in evolution of organisms to «force of growth», or a batmizm, i.e. desire or unwillingness of an animal to have more developed this or that part of a body. He explained inheritance of acquired characters with imprinting them in memory (so-called mnemogenezis). The psycholamarkizm which, using the ideas became further development of these views vitalism (see), tried to explain adequacy of variability and the adaptive nature of evolution of organic forms with influence of mental factors. According to views of psikholamarkist [A. A. Pauli, And. A. Wagner, etc.], animal, their bodies and parts of bodies, «know» how to react to changes of conditions of the environment; these changes are reasonable and are descended.

The theory of a continuity of germ plasm which is put forward by A. Veysman in 1883 and the statement by it of impossibility of inheritance of acquired signs (see. Veysmana theory ) sharply aggravated contradictions between supporters of L. — neolamarkist and Darwinism — neodarwinians. From this point the long-term dispute of lamarkist — supporters of searches of the reason of development out of an organism (the concept of an ektogenez) — with the neodarwinians developing the ideas began, according to the Crimea the reason of development is in an organism and is not dependent on external environment (the concept of autogenesis). Before reopening of laws of Mendel (see. Mendel laws ) and divisions of a concept variability (see) on hereditary and not hereditary the similar antagonism of concepts ekto-and autogenesis was historically clear and justified. It agrees sovr, to the representations created at the beginning of 20 century, individual and historical development is defined by interaction of external and internal factors onto-and phylogenesis. Thus, concepts of L. as purely ektogenetichesky theory, as well as purely autogenetic concepts, actually became obsolete by the end of the first quarter of 20 century. Synthesis of genetics and classical Darwinism led to the fact that concepts of L. finally lost any actual and theoretical basis. However obscurity of genetic mechanisms of interaction of external and internal factors in processes onto-and phylogenesis of organisms led in the first quarter of 20 century to nek-rum to revival of interest of scientists in the ideas of L.

In the 20th 20 century avstr. the biologist P. P. Kammerer made an attempt to experimentally confirm inheritance of acquired characters. Its first experiments, appear, confirmed the validity of the main dogma of L. Odnako their recheck did not repeat the results received by it. At the beginning of the 20th 20 century I. P. Pavlov charged to the employee to check a possibility of inheritance of conditioned reflexes. The data obtained by it as if spoke again about a possibility of lamarkistsky interpretation of the studied problem. N. K. Koltsov drew I. P. Pavlov's attention that repeated carrying out experiences with various generations of rats unconsciously for the experimenter led to improvement of its methodical receptions: as a result conditioned reflexes at rats of succeeding generations were developed quicker, than at previous, as led finally to incorrect theoretical conclusions. During the recheck results of experiences really were not confirmed, and I. P. Pavlov in the open letter published in «Truth» asked not to rank it as supporters of L.

Synthesis of genetics and Darwinism in the late twenties — the beginning of the 30th of 20 century led to the fact that L. finally lost the influence, and his few supporters actually acted from positions of open anti-Darwinism. Under the guise of criticism of autogenesis certain scientists [T. D. Lysenko, I. I. Prezent, R. Glavinic, etc.] continued to uphold wrong, mechanistic views on the nature of heredity, speciation, natural selection etc. In particular, T. D. Lysenko and his followers under the guise of development of scientific heritage of I. V. Michurin actively revived the ideas of L., having used at the same time the concepts «Michurinsk biology» and «Soviet creative Darwinism»; as examples of inheritance of acquired characters «vegetative hybridization», «alteration» of genetically different winter grades grain in summer and vice versa were widely propagandized, etc. Pereproverka of results of experiences of T. D. Lysenko and his supporters showed their full scientific insolvency. However as a result of a session of VASHNIL in August, 1948 which led to monopolization of views of supporters of T. D. Lysenko, lamarkistsky influence affected 40 at the end — the beginning of the 50th some sections of biology, in particular microbiology. With the Lamarkistsky ideas the textbooks which were also published in our country from 1948 to 1964 for higher education institutions, including and for medical in-t, on biol, to disciplines were sated.

Meanwhile researches in the area molecular biology (see) and molecular genetics (see) it was convincingly proved that the flow of genetic information is unidirectional >>>(DNK-RNK-belok-priznak). These researches at molecular level showed not hereditary nature of the modification changes arising as individual devices of an organism by Wednesday again.

The developed researches of genetic mechanisms of development of an organism, the opened possibilities of practical use of achievements of molecular biology with special distinctness showed that harm which was done to the Soviet biological science by monopolization of views of T. D. Lysenko and his followers. In this regard the October (1964) Plenum of the Central Committee of the CPSU which laid the foundation for resolute reorganization of situation in biol, sciences in the USSR had basic value, later to-rogo measures for recovery and development sovr, genetic and other directions in knowledge of patterns of development of organic forms were taken.

Opening amer. biologists D. Baltimore and H. Temin of the phenomenon of the return transcriptions (see), i.e. possibilities of transfer of information not only from DNA to RNA, but also from RNA to DNA, revived hope for confirmation of a possibility of inheritance of acquired characters at some lamarkist. However, as showed further researches, detection of the phenomenon of reverse transcription does not demonstrate even existence of such flow of genetic information which could provide inheritance of acquired characters.

See also Theory of evolution .

Bibliography: Blyakher L. Ya. Problem of inheritance of acquired characters, M., 1971; Davitashvili L. Sh. Current state of theory of evolution in the West, M., 1966; History of biology since the most ancient times before the beginning of the 20th century, under the editorship of L. Ya. Blyakher, etc., page 117, etc., M., 1972; History of biology since the beginning of the 20th century up to now, under the editorship of L. Ya. Blyakher, etc., M., 1975; To and mm of e p e r the Item. The general biology, the lane with it., M. — L., 1925; about N e, the Riddle of heredity, the lane with it., L., 1926; Quietly in E. S., Vermel Yu. M. and B. S. Cousins. Sketches according to the theory of evolution, M., 1924.

H. N. Vorontsov.