Strictly speaking, metamorphosis is any transformation, a transformation taking place in the Universe. This term is quite general and is used in various fields of scientific knowledge. In this article we will consider the concept from the point of view of biology. Within the framework of the science of life, it is more correct to call the phenomenon “metamorphosis” in the masculine gender, then both possible options will be used.
So, in the biology of metamorphosis - this is a pronounced morphological change in a living organism, without fail occurring during its ontogenesis. The phenomenon is observed both in plants and in animals. In the latter, metamorphosis occurs in the life cycle of most invertebrates and some vertebrates: cyclostomes, fish, and 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 formed adult organism as a result is fundamentally different from the newborn in structure, physiology and vital activity.
For animals, metamorphosis is not only a sharp change in the structure of the body. The phenomenon is accompanied by a change in habitat and living conditions. The vital activity of the adult organism is completely unlike that of the larval stages, the difference lies in the habitat, food consumed and many other details. Thus, we find the most important value of metamorphosis in nature, it provides a decrease in biological competition for food, habitat and other factors between organisms of different generations of the same species.
Let us consider metamorphosis in animals in more detail. Perhaps the most striking example is the insect class. Metamorphosis is characteristic of all representatives of this group. The process is either complete transformation or incomplete. Complete metamorphosis involves three stages of the development of the body: a worm-shaped larva, a pupa (an immobile 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 characteristic of dipterans (flies, mosquitoes), hymenoptera (bees, bumblebees, wasps), Lepidoptera (butterflies), and Coleopterans (ladybugs). With incomplete metamorphosis, only two stages of development are observed: a larva similar to an adult morphologically, and, in fact, an adult insect. Incomplete transformation is characteristic of Orthoptera (locusts, grasshoppers, bears), Equine-winged aphids (aphids), and Hemoptera (bugs).
For higher plants, metamorphosis is a modification of individual organs in connection with the functions performed by them, and not the transformation of the whole organism. As a rule, embryonic rather than fully formed organs enter the process. Plant metamorphoses are also called modifications. This, for example, bulbs (onions), thorns (cactus), tendrils (grapes), rhizome (ginger), tubers (potatoes) and much more. The significance of metamorphosis for plants lies in their adaptation to environmental conditions. So, for example, thorns (modified leaves) found in plants living in hot climates, by their shape, reduce evaporation from the surface of the leaf.