Lamarckism is an evolutionary concept based on the theory put forward by Jean Baptiste Lamarck at the beginning of the 19th century in the treatise “ Philosophy of Zoology ”. The views of Lamarck himself are quite difficult to understand, since they are based on a number of concepts of the eighteenth century that are completely uninterpreted within the framework of modern science ( matter originally created by God as a passive principle and nature as order and energy for its implementation; the concept of five elements , of which ether plays the most important role, in the form of "thin fluids" circulating in organic bodies; the constant spontaneous generation of life, including its complex forms, from inorganic and organic matter; denial of the extinction of species c; denial of the presence of the nervous system and sexual reproduction in "lower animals", etc.). In this regard, modern "Lamarckism" resembles them only in the most general terms. In a broad sense, various evolutionary theories are attributed to Lamarckian ones (mainly that arose in the 19th - first third of the 20th centuries), in which the desire for perfection, inherent in organisms, is considered as the main driving force of evolution (change of species). As a rule, great importance in such theories is given to the influence of “exercise” and “non-exercise” of organs on their evolutionary destinies, since it is assumed that the consequences of an exercise or non-exercise can be inherited [1] .
Content
The Principle of Excellence
Lamarck distributed all the animals into six steps, levels (or, as he said, “gradations”) according to the complexity of their organization. The ciliates are the farthest from humans, the mammals are closest to him. At the same time, the desire to develop from simple to complex, to move up the "steps" is inherent in all living things.
In the living world, a smooth evolution is constantly happening. Based on this, Lamarck came to the conclusion that in reality there are no species in nature, there are only individual individuals. Lamarck consistently applied in his theory the famous Leibniz principle: "Nature does not make leaps." Denying the existence of species, Lamarck referred to his vast experience in taxonomy:
- “Only one who has long and hard dealt with the identification of species and turned to rich collections can know to what extent species merge with one another. I ask, what experienced zoologist or botanist is not convinced of the solidity of what I just said? Climb up to fish , reptiles , birds , even mammals, and you will see gradual transitions between neighboring species and even genera everywhere. ”
When asked why a person does not notice the constant transformation of one species into another, Lamarck answered as follows: “Suppose that human life lasts no more than one second compared to the life of the universe, in this case not a single person who engages in contemplating the clockwise will see how she gets out of her position. " Even after dozens of generations, its movement will not be noticeable.
Laws of Evolution by Lamarck
Improving, organisms are forced to adapt to environmental conditions. To explain this, the scientist formulated several "laws". First of all, it is the “law of exercise and non-exercise of organs." The most famous of the examples cited by Lamarck was the example of giraffes . Giraffes have to constantly crank their neck to reach the leaves growing above their heads. Therefore, their necks become longer, extended. To catch ants in the depths of the anthill, the anteater has to constantly extend its tongue, and it becomes long and thin. On the other hand, the mole underground only interferes with the eyes, and they gradually disappear.
If the body is often practiced, it develops. If the organ does not exercise, it gradually dies.
Another "law" of Lamarck is the "law of inheritance of acquired characteristics." Useful traits acquired by animals, according to Lamarck, are transmitted to offspring. Giraffes passed the elongated neck to their descendants, anteaters inherited a long tongue, and so on.
Contemporaries Reaction
Lamarck's theory did not find understanding among contemporaries. Some scientists left the “Philosophy of Zoology” without any attention, while others criticized it harshly. Lamarck presented his book as a gift to Napoleon Bonaparte , but even the emperor she did not cause any sympathy.
Even Charles Darwin initially very sharply spoke about the book of Lamarck: "May heaven save me from the stupid Lamarckian" desire for progress "," adaptation due to the desire of animals ""; “Lamarck hurt the issue with his ridiculous, albeit smart work.” However, later he was forced to accept some principles of the teachings of Lamarck. In particular, he put forward the hypothesis of pangenesis , which was a development of Lamarck's idea of the inheritance of acquired characteristics.
But, nevertheless, the revival of Lamarckism began precisely with the advent of Darwin's evolutionary theory in 1859 .
Weisman Experiences
August Weisman's experiments were an attempt to prove the failure of Lamarck's theory. Weismann bred mice generation after generation, chopping off their tails. According to the theory of Lamarck, as a result, they should atrophy, since they were not used in life. However, no changes have occurred. This can be explained by the fact that at the genetic level no changes occurred that contributed to the death of the tail in future generations of mice.
Lamarckism and modernity
The thesis of Lamarckism on the inheritance of acquired changes has caused the greatest number of disputes, which continue to this day. In the second half of the 20th century, Lamarckism was compromised in the professional community due to the fact that the Soviet agronomist Trofim Lysenko , whose methods were contrary to the ideas of most biologists, adhered to views close to Lamarckism (the so-called "Soviet creative Darwinism"). Nevertheless, at present, a number of scholars continue to advocate Lamarckian concepts. Of the most significant attempts, the works of the Australian immunologist Edward Steele [2] should be noted, who believes that the phenomena described by him in the field of tissue transplantation receive a more satisfactory explanation from Lamarckian positions.
In addition, in recent years, the so-called CRISPR cassettes in bacterial DNA have been increasingly studied, which are used to insert information from bacteriophage DNA (bacterial viruses) into the bacterial DNA. Due to this information, the bacterium can resist the bacteriophage by recognizing its DNA (by the recorded fragment in its CRISPR cassette) and blocking it if the bacteriophage DNA has entered the bacterial cell. If you approach from a formal standpoint and consider bacteriophages as part of the external environment, then direct recording of information about the bacteriophage in the DNA of a bacterium is a purposeful adjustment (adaptation) of the organism to the environment, namely, the evolution mechanism that corresponds to the principles of Lamarckism [3] - in contrast Darwinism , which speaks of completely random mutations that “at random” may prove useful to the body. Thus, specifically, this mechanism of protection against bacteriophages may correspond to the principles of Lamarckism.
According to the botanist Conway Zirkl, the inheritance of acquired characters seems so promising that it is popular with those who want to quickly remake humanity [4] .
Application of the principles of Lamarckism
In artificial life modeling systems, Lamarckism in combination with “genetic memory” is often used to accelerate the evolution of innate behavior, for this the entire memory of the modeled individual is passed on to its offspring. Unlike classical genetic memory, only the previous generation's memory is passed on to offspring. [ clarify ] In this case, Lamarckism can be combined with Darwinism , which can be used to model other aspects of models of organisms [5] .
See also
- Lysenko
- Neolamarckism
Notes
- ↑ Vorontsov N. N. Development of evolutionary ideas in biology. - M .: Progress-Tradition, 1999. - S. 201-210. - 640 s. - ISBN 5-88800-107-4 .
- ↑ Steele E., Lindley R., Blandan R. What if Lamarck is right? Immunogenetics and evolution . - M .: Mir, 2002 .-- 237 p.
- ↑ Lecture "Genetic variation in bacteria" microbiologist Konstantin Severinov
- ↑ Mark Popovsky . The case of academician Vavilov. - M .: Book, 1990. - S. 119. - 100,000 copies.
- ↑ Jones MT AI Application Programming. - ISBN 1-58450-278-9 .