What does development without metamorphosis mean? Types of development

Strictly speaking, metamorphosis is any transformation, transformation that occurs in the Universe. This term is quite general and is used in a wide variety of areas of scientific knowledge. In this article we will look at the concept from a biological point of view. Within the framework of the science of life, it is more correct to call the phenomenon “metamorphosis”, in the masculine gender; in what follows, both possible options will be used.

So, in biology, metamorphosis is a pronounced morphological change in a living organism, which necessarily occurs during its ontogenesis. The phenomenon is observed in both plants and animals. In the latter, metamorphosis occurs in most invertebrates and some vertebrates: cyclostomes, fish, amphibians. The essence of the process is the transformation of the larval organism (in animals) or some organs (in plants) in such a way that the resulting adult organism is radically different from the newborn in structure, physiology and life activity.

For animals, metamorphosis is not only a sharp change in the structure of the body. The phenomenon is accompanied by a change in the environment and living conditions. The life activity of an adult organism is completely different from that of the larval stages; the difference lies in the food consumed and many other details. we discover the critical importance of metamorphosis in nature; it ensures a reduction in biological competition for food, habitat and other factors between organisms of different generations of the same species.

Let's take a closer look at metamorphosis in animals. The most striking example would be, perhaps, the class of insects. Metamorphosis is characteristic of all representatives of this group. The process is either a complete transformation or an incomplete one. Complete metamorphosis involves three stages of development of the organism: a worm-like larva, a pupa (a stationary stage, during which the body of the larva is completely destroyed and a new body of an adult is formed) and an adult insect. This type of phenomenon is typical for Diptera (flies, mosquitoes), Hymenoptera (bees, bumblebees, wasps), Lepidoptera (butterflies), Coleoptera (ladybugs). With incomplete metamorphosis, only two stages of development are observed: the larva, which is morphologically similar to the adult, and, in fact, the adult insect. characteristic of Orthoptera (locusts, grasshoppers, mole crickets), Homoptera (aphids) and Hemiptera (bugs).

For higher plants, metamorphosis is a modification of individual organs in connection with the functions they perform, and not a transformation of the entire organism. As a rule, rudimentary rather than fully formed organs enter the process. Metamorphoses of plants are also called modifications. These are, for example, bulbs (onions), spines (cactus), tendrils (grapes), rhizomes (ginger), tubers (potatoes) and much more. The significance of metamorphosis for plants lies in their adaptation to environmental conditions. For example, spines found on plants living in hot climates, by their shape, help reduce evaporation from the leaf surface.

And animals vary significantly.

Metamorphosis in plants

It is expressed in modifications of the main organs that occur in ontogenesis and are associated with a change in the functions they perform or the operating conditions. True metamorphosis - the transformation of one organ into another with a strong change in form and function, occurs in many herbaceous plants (the gradual death of an above-ground shoot and the transition to a rhizome, bulb, corm during an unfavorable period). In most cases, it is not the differentiated organs of an adult plant that undergo metamorphosis, but their rudiments, for example, when part of the shoots and leaves are transformed into spines and tendrils. The determination of the organ rudiment, which determines its final appearance and occurs at different stages of its development, is associated with the accumulation of certain physiologically active substances and depends on external and internal factors.

Metamorphosis in animals

Unlike plants, in animals, during metamorphosis, the entire structure of the body undergoes changes. Metamorphosis is characteristic of most groups of invertebrates and some vertebrates - lampreys, a number of fish, and amphibians. Metamorphosis is usually associated with a sharp change in the animal’s lifestyle during ontogenesis, for example, with the transition from a free-swimming to an attached lifestyle, from aquatic to terrestrial, etc. In the life cycle of animals developing with metamorphosis, there is at least one larval stage, essentially different from an adult animal. In such animals, different stages of ontogenesis perform different vital functions that contribute to the preservation and prosperity of the species (for example, settlement occurs at the larval stage, and nutrition and growth occur at the adult stage). Metamorphosis in animals is regulated by hormones.

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Frog caviar

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Tadpoles

Metamorphic tadpole

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Metamorphosis in invertebrates

Metamorphosis in vertebrates

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Literature

• // Biological encyclopedic dictionary / Ch. ed. M. S. Gilyarov; Editorial team: A. A. Baev, G. G. Vinberg, G. A. Zavarzin and others - M.: Sov. encyclopedia, 1986. - pp. 354–355. - 100,000 copies.

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Excerpt characterizing Metamorphosis

After suffering, Prince Andrei felt a bliss that he had not experienced for a long time. All the best, happiest moments in his life, especially his earliest childhood, when they undressed him and put him in his crib, when the nanny sang over him, lulling him to sleep, when, burying his head in the pillows, he felt happy with the sheer consciousness of life - he imagined to the imagination not even as the past, but as reality.
Doctors were fussing around the wounded man, the outline of whose head seemed familiar to Prince Andrei; they lifted him up and calmed him down.
– Show me... Ooooh! O! oooooh! – one could hear his groan, interrupted by sobs, frightened and resigned to suffering. Listening to these moans, Prince Andrei wanted to cry. Was it because he was dying without glory, was it because he was sorry to part with his life, was it because of these irretrievable childhood memories, was it because he suffered, that others suffered, and this man moaned so pitifully in front of him, but he wanted to cry childish, kind, almost joyful tears.
The wounded man was shown a severed leg in a boot with dried blood.
- ABOUT! Ooooh! - he sobbed like a woman. The doctor, standing in front of the wounded man, blocking his face, moved away.
- My God! What is this? Why is he here? - Prince Andrei said to himself.
In the unfortunate, sobbing, exhausted man, whose leg had just been taken away, he recognized Anatoly Kuragin. They held Anatole in their arms and offered him water in a glass, the edge of which he could not catch with his trembling, swollen lips. Anatole was sobbing heavily. “Yes, it’s him; “Yes, this man is somehow closely and deeply connected with me,” thought Prince Andrei, not yet clearly understanding what was in front of him. – What is this person’s connection with my childhood, with my life? - he asked himself, not finding an answer. And suddenly a new, unexpected memory from the world of childhood, pure and loving, presented itself to Prince Andrei. He remembered Natasha as he had seen her for the first time at the ball in 1810, with a thin neck and thin arms, with a frightened, happy face ready for delight, and love and tenderness for her, even more vivid and stronger than ever, awoke in his soul. He now remembered the connection that existed between him and this man, who, through the tears that filled his swollen eyes, looked dully at him. Prince Andrei remembered everything, and enthusiastic pity and love for this man filled his happy heart.
Prince Andrei could no longer hold on and began to cry tender, loving tears over people, over himself and over them and his delusions.
“Compassion, love for brothers, for those who love, love for those who hate us, love for enemies - yes, that love that God preached on earth, which Princess Marya taught me and which I did not understand; That’s why I felt sorry for life, that’s what was still left for me if I were alive. But now it's too late. I know it!"

The terrible sight of the battlefield, covered with corpses and wounded, combined with the heaviness of the head and with the news of the killed and wounded twenty familiar generals and with the awareness of the powerlessness of his previously strong hand, made an unexpected impression on Napoleon, who usually loved to look at the dead and wounded, thereby testing his spiritual strength (as he thought). On this day, the terrible sight of the battlefield defeated the spiritual strength in which he believed his merit and greatness. He hastily left the battlefield and returned to the Shevardinsky mound. Yellow, swollen, heavy, with dull eyes, a red nose and a hoarse voice, he sat on a folding chair, involuntarily listening to the sounds of gunfire and not raising his eyes. With painful melancholy he awaited the end of that matter, which he considered himself to be the cause of, but which he could not stop. Personal human feeling for a short moment took precedence over that artificial ghost of life that he had served for so long. He endured the suffering and death that he saw on the battlefield. The heaviness of his head and chest reminded him of the possibility of suffering and death for himself. At that moment he did not want Moscow, victory, or glory for himself. (What more glory did he need?) The only thing he wanted now was rest, peace and freedom. But when he was at Semenovskaya Heights, the chief of artillery suggested that he place several batteries at these heights in order to intensify the fire on the Russian troops crowded in front of Knyazkov. Napoleon agreed and ordered news to be brought to him about what effect these batteries would produce.
The adjutant came to say that, by order of the emperor, two hundred guns were aimed at the Russians, but that the Russians were still standing there.
“Our fire takes them out in rows, but they stand,” said the adjutant.
“Ils en veulent encore!.. [They still want it!..],” Napoleon said in a hoarse voice.
- Sire? [Sovereign?] - repeated the adjutant who did not listen.
“Ils en veulent encore,” Napoleon croaked, frowning, in a hoarse voice, “donnez leur en.” [You still want to, so ask them.]

Real and possible - where is the border between them? With the “firmament of the earth” everything is more or less clear. The situation is different in the world of fiction. The dominant tropes here are: metaphor, metonymy, metamorphosis, synecdoche, hyperbole, litotes. They are the ones who erase all boundaries between the real and the possible, inviting everyone to plunge into the world of limitless fantasies, the world of harmony and spirit, and thereby understand the deep structures of reality. But today is not about this, or rather, about this, about one of the tropes - metamorphosis. Who is she and what is she capable of?

Metamorphosis is...

Along with such figurative means of language as hyperbole, metaphor and comparison, metamorphosis is considered one of the most ancient and striking stylistic devices in terms of expressiveness. Mythology, folklore, ballads, fables - it was from them that her ascent and development began. The path was long and difficult. Today, the Encyclopedia of Mythology gives the following definitions: firstly, metamorphosis is the transformation, transformation of one creature or object into another. Secondly, one form is transformed, transforms into another and acquires a new appearance and function. And, finally, third - extraordinary, mystical changes in something, significant transformations.

World of Fiction

Modern literature is still full of contradictions. In stylistics there is no unity of views on the nature of metamorphosis and its main functions. According to the famous Russian linguist D.E. Rosenthal, metamorphosis in literature is rather the process of transition itself, the transformation of one phenomenon into another, and comparison and metaphor, with which metamorphosis is often confused, are already the result of some changes. Metamorphosis is much brighter, more colorful and active than metaphor, and more decisive than comparison.

Other opinions

Metamorphosis and metaphor must be clearly distinguished. This opinion is shared by N.D. Arutyunova. According to her research, metamorphosis is an episode, action, scene, phenomenon that runs through the entire development of the plot, while metaphor is a kind of penetration into the semantics of a word; it generates or transforms meanings.

EAT. Meletinsky believes that metamorphosis is a reflection of the “essential features of the early mythological worldview,” according to which nature, phenomena, objects, gods, and people are fused into a single, constant and inseparable whole. Therefore, it is common for all existing things to pass into each other, from the “kingdom of the living” to the “kingdom of the dead,” from “the other world” to “this world” and vice versa. How is this possible? Thanks to obligatory memorphoses.

A striking example of the use of metamorphosis in modern literature can be considered the work “Metamorphosis” by F. Kafka. In it, the main character Gregor Samsa is the most simple man in the street. Waking up one morning, he realizes that he has turned into an insect, disgusting and huge. How did this metamorphosis occur? The reasons for it are unknown. The author simply confronts the reader with a fact. He is more interested in the consequences - what happened next, how the human mind, fully aware of what happened, continues to live on, locked in the body of an insect, and how the world around it accepts its ugliness.

In its most general sense, metamorphosis is the process of transformation or transformation of something. Most often we are talking about processes occurring in the universe. It is especially relevant to use this term in the context of biology.

In this article we will look at what metamorphosis is from a biological point of view.

Metamorphosis is...

Metamorphosis or metamorphosis is a deep transformation of the structure of the organism as a whole or only its individual parts. Such transformations occur as a result of individual development or, in scientific terms, ontogenesis. If we compare metamorphoses in plants and animals, they have significant differences.

Metamorphosis in plants is usually accompanied by the transformation of one organ into another. In this case, a radical change in the form and function of this organ occurs. For example, the transition of a shoot into a bulb, etc.

Metamorphosis in animals indicates changes in the entire structure of the body. In particular, such a transition is characteristic of most invertebrates, some lampreys, fish and amphibians. For example, this could be the transition from a larva to an adult. Quite often, the transition is associated with a change in the individual’s lifestyle.

You can find many other interesting definitions, including those about animals and plants, in a special section of our website -.

There are two main types of development: direct (non-larval, development without metamorphosis) and indirect (larval, development with metamorphosis).

Direct development occurs in invertebrates (free-living flatworms, rotifers, oligocheta, leeches, arachnids) and chordates (cyclostomes (hagfish), some fish, reptiles, birds, mammals). In this case, an individual emerges from the egg shells or the mother’s body (is born, hatches), and looks similar to an adult organism. The differences relate mainly to body size, some proportions, underdevelopment of some organs and organ systems, and the inability to reproduce (underdeveloped reproductive system).

With this type of development, a larva emerges from the egg and does not look like an adult. After a certain period of life, the larva begins to transform into an adult, this process is called metamorphosis.

There are several types of metamorphosis: evolutive (the transformation of a larva into an adult occurs gradually) (for example, annelids, crustaceans), revolutionary (catastrophic) (a rapid transformation of a larva into an adult occurs) (for example, insects with complete transformation), necrobiotic (with metamorphosis degenerative changes predominate over progressive ones) (for example, in ascidians).

In addition, metamorphosis is divided into primary (in the vast majority of living organisms that have metamorphosis) and secondary (for example, in insects). Primary is called metamorphosis, which was originally inherent in living organisms. That is, these living organisms cannot develop without metamorphosis, since due to the small supply of nutrients in the egg and some other reasons, they cannot immediately form an individual of such a level of complexity as an adult form during the process of embryogenesis. In this case, an organism of a simpler structure, but capable of independent existence, is formed first - a larva. After a certain period of life, the larva accumulates the nutrients necessary for its further development, and after that it turns into an adult form - metamorphosis occurs.

However, the larva is more simply built, and therefore less adapted to existence. Therefore, it is evolutionarily advantageous to quickly go through a greater number of stages in the egg and create a more complexly constructed larva, or even go through all stages of development in the egg and thus move on to the direct type of development. A similar trend can be seen in sponges, coelenterates and a number of other organisms. This phenomenon is called embryonication of the larval stage. Embryonization can be incomplete or complete. With incomplete embryonication in evolutionary descendants, a greater number of developmental stages occur in the egg and a more complexly constructed larva is formed compared to their evolutionary ancestors. With complete embryonication, all larval stages begin to occur in the egg and an organism of the same level of complexity as the adult form immediately emerges from the egg, i.e. there is a transition to a direct type of development.