Adaptation of organisms to environmental conditions examples. Types of adaptation: morphological, physiological and behavioral adaptations. Symptoms of oxygen starvation are expressed by constant fatigue and depression, accompanied by insomnia.

As you know, a huge number of various living organisms live on the territory of our planet. Each of them lives exclusively in those living conditions to which it is adapted. The property of organisms to adapt to new features of the environment is called adaptation. This adaptability is a combination different features physiological structure and behavioral characteristics of a particular species, which enable it to live in certain environmental conditions. Let's talk about the features of adaptation of organisms to environmental conditions in a little more detail.

Adaptation is the most important part of the evolutionary process, it helps the body to solve certain environmental problems that the environment sets before it. Such tasks are solved by changing, improving, and sometimes even disappearing individuals. These processes help to achieve a state of adaptation of organisms to the ecological niches they occupy. Accordingly, adaptation can be viewed as a broad basis for the appearance or disappearance of certain organs, the division of species into different ones, the formation of new populations and varieties, and also for the complexity of organization.

Adaptation is a continuous process that affects a variety of characteristics of the body.
Some new adaptations can arise only if a particular individual has hereditary information that contributes to a change in structures or functions in the right direction. So the development of the respiratory system in mammals and insects is possible only under the control of certain genes.

Consider the different types of adaptation of living organisms in more detail.

Passive Defense

During evolution, many living individuals have developed certain means to protect themselves and their offspring. So a striking example of such adaptation is considered to be protective coloration, as a result of which individuals become difficult to distinguish and protected from predators. For example, eggs laid on the sand or the ground are gray and brown with different spots, respectively, they are difficult to find among the surrounding soil. In areas inaccessible to predators, eggs in most cases are devoid of color.

Desert animals also use the same type of adaptation, because their color is usually represented by different shades of yellow-brown and sandy-yellow.
As a variant of passive protection, scaring coloring can also be considered, because it helps to protect yourself from predators, as if warning about the inedibility of a particular organism.

In addition, this kind of adaptation can also be considered in cases where the body develops similarity with environment. Examples include beetles that look like lichens, cicadas that look like thorns in bushes, and stick insects that are indistinguishable from twigs.

Passive defensive adaptation mechanisms also include the high fecundity of certain individuals, as well as other means, such as hard coatings in crayfish and crabs, spines, thorns, and poisonous hairs in plants.

Relativity and expediency of adaptation

Changes in the structure and behavior of organisms appear in response to certain environmental problems, respectively, they differ in relativity and expediency. So if we talk about relativity, then it consists in the limitation of such adaptive changes depending on living conditions. So, for example, the special pigmented color of birch moth butterflies, in contrast to their white varieties, becomes noticeable and valuable only if you see them on a smoked tree trunk. When environmental conditions change, such adaptations may not bring any benefit to the body, and even harm it.

For example, active and constant growth of incisors in rats is only useful if they eat solid food. When switching to a soft diet, the incisors can grow to an excessive size and make eating impossible.

It is also worth emphasizing that adaptive changes are not able to provide their owners with 100% protection. The special coloration of bees and wasps protects them from being eaten by many birds, but there are varieties of birds that do not pay any attention to it. Hedgehogs are capable of eating poisonous snakes. And that hard shell that protects ground turtles from enemies is broken when they are dropped from a height by birds of prey.

Adaptation of organisms in human life

It is the adaptive properties of various organisms that explain the emergence of new bacteria and other microorganisms that are resistant to drugs. This trend is especially clear with the use of antibiotics, as over time their use becomes ineffective. Microorganisms can learn to synthesize a special enzyme that destroys the drug used, or their cell walls become impermeable to the active substances of the drug.

The emergence of resistant strains of microorganisms is often the fault of doctors who use minimal doses of drugs to reduce the likelihood of developing side effects. If we transfer this feature to the world, it becomes clear how insects and mammals develop resistance to various kinds of poisons.

The adaptive properties of all organisms should be considered as part of natural selection.

arises in the process of evolution to solve the environmental problems of the organism, presented by the environment. They are a changing, improving, sometimes disappearing adaptation of organisms to specific environmental factors. As a result of the development of adaptation, a state of adaptation (or correspondence of the morphology, physiology, and behavior of organisms) to the ecological niches occupied by them is achieved, which represent the entire set of environmental conditions and lifestyle of a given organism. That. adaptation can be considered a broad basis for the emergence or disappearance of organs, the divergence (divergence) of species, the formation of new populations and species, and the complication of organization.

The process of developing adaptation occurs constantly and many signs of the body are involved in it. [show] .

The evolution of birds from reptiles included, for example, successive changes in bones, muscles, integuments, and limbs.

An increase in the sternum, a restructuring of the histological structure of the bones, which gave them lightness along with strength, the development of plumage, which led to better aerodynamic properties and thermoregulation, and the transformation of a pair of limbs into wings, provided a solution to the problem of flight.

Some representatives of birds subsequently developed adaptations to a terrestrial or aquatic lifestyle (ostrich, penguin), while secondary adaptations also captured a number of characters. Penguins, for example, changed their wings to fins, and their covers became waterproof.

However, an adaptation is formed only if there is a type of hereditary information in the gene pool that contributes to a change in structures and functions in the required direction. Thus, mammals and insects use lungs and tracheas, respectively, for breathing, which develop from different primordia under the control of different genes.

Adaptation sometimes leads to a new mutation, which, being included in the genotype system, changes the phenotype in the direction of more effective solution environmental tasks. This way of occurrence of adaptation is called combinative.

Different adaptations can be used to solve one ecological problem. Thus, thick fur serves as a means of thermal insulation in bears, arctic foxes, and in cetaceans, the fatty subcutaneous layer.

There are several classifications of adaptation.

According to the mechanism of action allocate

Passive protection devices

• protective coloration. Thanks to the protective coloration, the organism becomes difficult to distinguish and, therefore, protected from predators.
  • Bird eggs laid on sand or on the ground are gray and brown with spots, similar to the color of the surrounding soil. In cases where eggs are not available to predators, they are usually devoid of coloration.
  • Butterfly caterpillars are often green, the color of the leaves, or dark, the color of the bark or earth.
  • Bottom fish are usually painted to match the color of the sandy bottom (stingrays and flounders). At the same time, flounders also have the ability to change color depending on the color of the surrounding background.
  • The ability to change color by redistributing the pigment in the integument of the body is also known in terrestrial animals (chameleon).
  • Desert animals, as a rule, have a yellow-brown or sandy-yellow color.
  • Monochromatic protective coloration is characteristic of both insects (locusts) and small lizards, as well as large ungulates (antelopes) and predators (lion).
  • Dissecting protective coloration in the form of alternating light and dark stripes and spots on the body. Zebras and tigers are hard to see already at a distance of 50-40 m due to the coincidence of the stripes on the body with the alternation of light and shadow in the surrounding area. Dissecting coloring violates ideas about the contours of the body.
• frightening (warning) coloring - also provides protection for organisms from enemies.

  Bright coloration is usually characteristic of poisonous animals and warns predators about the inedibility of the object of their attack. The effectiveness of warning coloration was the cause of a very interesting imitation phenomenon - mimicry. [show] .

  Mimicry is the similarity between defenseless and edible type with one or more unrelated species, well protected and with warning coloration. The phenomenon of mimicry is common in butterflies and other insects. Many insects mimic stinging insects. Beetles, flies, butterflies are known, copying wasps, bees, bumblebees.

  Mimicry is also found in vertebrates - snakes. In all cases, the similarity is purely external and is aimed at forming a certain visual impression in potential enemies.

  For mimic species, it is important that their numbers be small compared to the model they imitate, otherwise the enemies will not develop a stable negative reflex to warning coloration. The low number of mimic species is supported by a high concentration of lethal genes in the gene pool.

• the similarity of the shape of the body with the environment - beetles are known that resemble lichens, cicadas, similar to the thorns of those shrubs among which they live. Stick insects look like a small brown or green twig.

  The protective effect of a protective color or body shape is enhanced when combined with the appropriate behavior. For example, moth caterpillars in a defensive posture are similar to a plant branch. Selection destroys individuals whose behavior unmasks them.

• high fecundity
• other means of passive protection
  • The development of spines and needles in plants protects them from being eaten by herbivores.
  • Poisonous substances that burn hairs (nettle) play the same role.
  • Calcium oxalate crystals, formed in the cells of some plants, protect them from being eaten by caterpillars, snails and even rodents.
  • Formations in the form of a hard chitinous cover in arthropods (beetles, crabs), shells in mollusks, scales in crocodiles, shells in armadillos and turtles protect them well from many enemies. The quills of the hedgehog and porcupine serve the same.

Active protection devices, movement,
looking for food or a breeding partner

• improvement of the apparatus of movement, nervous system, sensory organs, development of means of attack in predatory

  The chemical organs of insects are amazingly sensitive. Male gypsy moths are attracted by the smell of the scent gland of a female from a distance of 3 km. In some butterflies, the sensitivity of taste receptors is 1000 times greater than the sensitivity of human tongue receptors. Nocturnal predators, such as owls, see perfectly in the dark. Some snakes have a well-developed ability to thermolocation. They distinguish objects at a distance if the difference in their temperatures is only 0.2 ° C.

Adaptations to the social way of life - the division of "labor" in bees.

Depending on the nature of the change

• adaptation with the complication of morphophysiological organization - the emergence of lobe-finned fish on land in the Devonian, which allowed them to give rise to terrestrial vertebrates

  For lobe-finned fish, the limbs were used for crawling along the bottom of reservoirs. Swallowing air and using oxygen by protrusion of the intestinal wall - primitive lungs - provided an opportunity to compensate for the lack of oxygen in the waters of that time. These structures allowed some fish to leave the waters for a while. Initially, such exits were made, apparently, on rainy days or wet nights. This is exactly what the American catfish (Ictalurus nebulosis) currently does. Subsequently, these structures developed into the lungs and limbs of land animals. Subsequently, the whole organization of fish underwent profound changes in the process of adaptation to life on land.

  Such changes during the development of a new habitat, expanding the range of functions based on structures that previously performed other functions, but changed in such a direction and to such an extent that they were able to take on new functions - is called pre-adaptation.

  The phenomenon of pre-adaptation once again emphasizes the adaptive nature of evolution, based on the selection of useful hereditary changes and progressive transformations of existing structures in the process of mastering new environmental conditions.

  By fixture scale

  • specialized adaptations . With the help of specialized adaptations, the organism solves specific problems in the narrow local conditions of the life of the species. For example, the structural features of the anteater's tongue provide food for ants.
  • common adaptations - allow to solve many problems in a wide range of environmental conditions. These include the internal skeleton of vertebrates and the external arthropods, hemoglobin as an oxygen carrier, etc. Such adaptations contribute to the development of various ecological niches, provide significant ecological and evolutionary plasticity, and are found in representatives of large taxa of organisms. So, the primary horny cover of ancestral forms of reptiles in the process historical development gave covers modern reptiles, birds, mammals. The scale of adaptation is revealed in the course of evolution of the group of organisms in which it arose for the first time.

  Thus, the structure of living organisms is very finely adapted to the conditions of existence. Any species trait or property is adaptive in nature and appropriate in a given environment, in given living conditions.

  Relativity and expediency of fitness of organisms

  Adaptations arise in response to a specific ecological task, so they are always relative and expedient. The relativity of adaptation lies in the limitation of their adaptive value to certain living conditions. Thus, the adaptive value of the pigmentation of moth butterflies in comparison with light forms is evident only on sooty tree trunks.

  When environmental conditions change, adaptations may turn out to be useless or even harmful to the organism. The constant growth of rodent incisors is very important feature but only when eating solid food. If a rat is kept on soft food, the incisors, without wearing out, grow to such a size that feeding becomes impossible.

  None of the adaptive features provides absolute security for their owners. Due to mimicry, most birds do not touch wasps and bees, but among them there are species that eat both wasps and bees, and their imitators. The hedgehog and the secretary bird eat poisonous snakes without harm. The shell of terrestrial turtles reliably protects them from enemies, but birds of prey lift them into the air and smash them on the ground.

  The biological expediency of the organization of living beings is manifested in the harmony between morphology, physiology, and the behavior of organisms. different types and their habitat. It also lies in the amazing consistency of the structure and functions of individual parts and systems of the organism itself. Supporters of the theological explanation of the origin of life saw biological expediency as a manifestation of the wisdom of the creator of nature. The teleological explanation of biological expediency proceeds from the principle of "ultimate goal", according to which life develops in a directed way due to an inherent striving towards a known goal. Since the time of J. B. Lamarck, there have been hypotheses linking biological expediency with the principle of an adequate response of organisms to changes in external conditions and the inheritance of such "acquired traits." A convincing argument in favor of the expediency of changes under the influence of the environment has long been recognized as the fact that microorganisms are "addicted" to drugs - sulfonamides, antibiotics. The experience of V. and E. Lederberg showed that this is not so.

  

  In a Petri dish on the surface of a solid nutrient medium, the microbe forms colonies (1). With a special stamp (2), the imprint of all colonies was transferred to the medium with lethal dose antibiotic (3). If at least one colony grew under these conditions, then it came from a colony of microbes that were also resistant to this drug. Unlike other colonies on the first Petri dish (4), it grew in the antibiotic tube (5). If the number of original colonies was large, then among them, as a rule, there was also a stable one. Thus, we are not talking about the directed adaptation of the microbe, but about the state of pre-adaptation, which is due to the presence in the genome of the microorganism of an allele that blocks the action of the antibiotic. In some cases, "resistant" microbes synthesize an enzyme that destroys the drug, in others, the cell wall becomes impermeable to the drug.

  The emergence of strains of microorganisms resistant to drugs is facilitated by the wrong tactics of doctors who, wanting to avoid side effects, prescribe low, sublethal doses of drugs. It is also possible to explain the emergence of forms resistant to poisons among insects and mammals - among mutant organisms there is a stable form that undergoes positive selection under the influence of a poisonous substance. For example, the resistance of rats to the warfarin used to kill them depends on the presence of a certain dominant allele in the genotype.

  The possibility of "direct adaptation" of organisms to the environment, "alteration of nature by assimilating conditions" was argued by some biologists as early as the 40-50s of the current century. The points of view given above correspond to idealistic views, and cannot explain biological expediency without drawing on the idea, if not of God, then of a special goal or program for the development of life that existed even before its occurrence.

  The biological expediency of the structure and functions of organisms develops in the process of life development. It is a historical category. This is evidenced by the change in the types of organization that occupy a dominant position in organic world planets. Thus, the dominance of amphibians for almost 75 million years was replaced by the dominance of reptiles, which lasted for 150 million years. During periods of dominance of any group, several waves of extinction are observed, which change the relative species composition of the corresponding large taxon.

  The emergence of any adaptation and biological expediency as a whole is explained by the work in nature for more than 3.5 billion years of natural selection. Of the many random deviations, it preserves and accumulates hereditary changes that have adaptive value. This explanation makes it possible to understand why biological expediency, when viewed in space and time, is a relative property of living beings and why, under specific living conditions, individual adaptations reach only the degree of development that is sufficient to survive in comparison with competitors' adaptations.

The identification of limiting factors is of great practical importance. First of all, for growing crops: applying the necessary fertilizers, liming the soil, reclamation, etc. allow to increase productivity, improve soil fertility, improve the existence of cultivated plants.

1. What does the prefix "evry" and "steno" mean in the species name? Give examples of eurybionts and stenobionts.

Wide tolerance limit of the species in relation to abiotic environmental factors, denoted by adding prefixes to the name of the factor "evry. The inability to tolerate significant fluctuations in factors or a low endurance limit is characterized by the prefix "steno", for example, stenothermic animals. Small temperature changes have little effect on eurythermal organisms and can be fatal for stenothermic ones. View adapted to low temperatures, is an cryophilic(from the Greek krios - cold), and to high temperatures - thermophilic. Similar patterns apply to other factors as well. Plants may be hydrophilic, i.e. demanding on water and xerophilous(dry-hardy).

In relation to content salts in the habitat, eurygales and stenogals are distinguished (from Greek gals - salt), to illumination - euryphotes and stenophots, in relation to to the acidity of the environment- Euryionic and stenionic species.

Since eurybiontism makes it possible to populate a variety of habitats, and stenobiontism sharply narrows the range of places suitable for the species, these 2 groups are often called evry - and stenobionts. Many terrestrial animals living in a continental climate are able to withstand significant fluctuations in temperature, humidity, and solar radiation.

Stenobionts include- orchids, trout, Far Eastern hazel grouse, deep-sea fish).

Animals that are stenobiont simultaneously with respect to several factors are called stenobionts in the broad sense of the word ( fish that live in mountain rivers and streams, do not tolerate too high temperatures and low oxygen content, inhabitants of the humid tropics, unadapted to low temperatures and low air humidity).

The eurybionts are Colorado potato beetle, mouse, rats, wolves, cockroaches, reeds, wheatgrass.

1. Adaptation of living organisms to environmental factors. Types of adaptation.

adaptation ( from lat. adaptation - adaptation ) - this is an evolutionary adaptation of the organisms of the environment, expressed in a change in their external and internal features.

Individuals that for some reason have lost the ability to adapt, in the conditions of changes in the regimes of environmental factors, are doomed to elimination, i.e. to extinction.

Types of adaptation: morphological, physiological and behavioral adaptations.

Morphology is doctrine of external forms organisms and their parts.

1.Morphological adaptation- this is an adaptation that manifests itself in adaptation to fast swimming in aquatic animals, to survival in conditions of high temperatures and moisture deficiency - in cacti and other succulents.

2.Physiological adaptations consist in the features of the enzymatic set in the digestive tract of animals, determined by the composition of the food. For example, the inhabitants of dry deserts are able to provide the need for moisture due to the biochemical oxidation of fats.

3.Behavioral (ethological) adaptations appear in a variety of forms. For example, there are forms of adaptive behavior of animals aimed at ensuring optimal heat exchange with the environment. Adaptive behavior can be manifested in the creation of shelters, movements in the direction of more favorable, preferred temperature conditions, choosing places with optimal humidity or illumination. Many invertebrates are characterized by a selective attitude towards light, which manifests itself in approaching or moving away from the source (taxis). Diurnal and seasonal migrations of mammals and birds are known, including migrations and flights, as well as intercontinental movements of fish.

Adaptive behavior can manifest itself in predators in the process of hunting (tracking and chasing prey) and in their prey (hiding, confusing the trail). The behavior of animals during the mating season and during the rearing of offspring is exceptionally specific.

There are two types of adaptation to external factors. Passive way of adaptation- this is an adaptation according to the type of tolerance (tolerance, endurance) consists in the emergence of a certain degree of resistance to this factor, the ability to maintain functions when the force of its influence changes .. This type of adaptation is formed as a characteristic species property and is realized at the cellular and tissue level. The second type of fixture active. In this case, the body, using specific adaptive mechanisms, compensates for the changes caused by the influencing factor, so that the internal environment remains relatively constant. Active adaptations are adaptations of a resistant type (resistance) that maintain the homeostasis of the internal environment of the body. An example of a tolerant type of adaptation is poikiloosmotic animals, an example of a resistant type is homoyosmotic .

1. Define a population. Name the main group characteristics of the population. Give examples of populations. Growing, stable and dying populations.

population- a group of individuals of the same species that interact with each other and jointly inhabit a common territory. The main characteristics of the population are as follows:

1. Number - the total number of individuals in a certain area.

2. Population density - the average number of individuals per unit area or volume.

3. Fertility - the number of new individuals that appeared per unit of time as a result of reproduction.

4. Mortality - the number of dead individuals in the population per unit of time.

5. Population growth - the difference between fertility and mortality.

6. Growth rate - average growth per unit of time.

Populations are characterized by a certain organization, the distribution of individuals over the territory, the ratio of groups by sex, age, and behavioral characteristics. It is formed, on the one hand, on the basis of the general biological properties of the species, and on the other hand, under the influence of abiotic environmental factors and populations of other species.

The structure of the population is unstable. The growth and development of organisms, the birth of new ones, death from various causes, changes in environmental conditions, an increase or decrease in the number of enemies - all this leads to a change in various ratios within the population.

Increasing or growing population- this is a population in which young individuals predominate, such a population is growing in number or is being introduced into the ecosystem (for example, countries of the "third" world); More often, there is an excess of births over deaths and the population grows to such an extent that an outbreak of mass reproduction may occur. This is especially true for small animals.

With a balanced intensity of fertility and mortality, a stable population. In such a population, mortality is compensated by growth and its number, as well as its range, are kept at the same level. . Stable population - is a population in which the number of individuals different ages changes evenly and has the character of a normal distribution (for example, we can name the population of Western European countries).

Decreasing (dying) population is a population in which the death rate exceeds the birth rate . A declining or dying population is a population dominated by older individuals. An example is Russia in the 1990s.

However, it cannot shrink indefinitely either.. At a certain level of abundance, the intensity of mortality begins to fall, and fecundity increases. . Ultimately, a declining population, having reached a certain minimum number, turns into its opposite - a growing population. The birth rate in such a population gradually increases and at a certain moment levels off with mortality, i.e., the population becomes stable for a short period of time. Decreasing populations are dominated by old individuals that are no longer able to reproduce intensively. This age structure indicates unfavorable conditions.

1. Ecological niche of the organism, concepts and definitions. Habitat. Mutual arrangement of ecological niches. The ecological niche of man.

Any kind of animal, plant, microbe is able to normally live, feed, reproduce only in the place where it has been "registered" by evolution over many millennia, starting from its ancestors. To refer to this phenomenon, biologists have borrowed term from architecture - the word "niche" and they began to say that each type of living organism occupies its own, unique ecological niche in nature.

Ecological niche of an organism- this is the totality of all its requirements for environmental conditions (the composition and regimes of environmental factors) and the place where these requirements are met, or the totality of the set biological characteristics and physical parameters of the environment that determine the conditions for the existence of a particular species, its transformation of energy, the exchange of information with the environment and their own kind.

The concept of an ecological niche is usually used when using the relationships of ecologically close species belonging to the same trophic level. The term "ecological niche" was proposed by J. Grinnell in 1917 to characterize the spatial distribution of species, that is, the ecological niche was defined as a concept close to the habitat. C. Elton defined an ecological niche as the position of a species in a community, emphasizing the particular importance of trophic relationships. A niche can be thought of as part of an imaginary multi-dimensional space (hypervolume), the individual dimensions of which correspond to the factors necessary for the species. The more the parameter varies, i.e. adaptation of a species to a particular environmental factor, the wider its niche. The niche can also increase in the case of weakened competition.

habitat of the species- this is the physical space occupied by a species, organism, community, it is determined by the totality of the conditions of the abiotic and biotic environment that provide the entire development cycle of individuals of the same species.

The habitat of the species can be designated as "spatial niche".

The functional position in the community, in the ways of processing matter and energy in the process of nutrition, is called trophic niche.

Figuratively speaking, if a habitat is, as it were, the address of organisms of a given species, then a trophic niche is a profession, the role of an organism in its habitat.

The combination of these and other parameters is commonly called an ecological niche.

ecological niche(from the French niche - a recess in the wall) - this is the place occupied by a biological species in the biosphere, includes not only its position in space, but also its place in trophic and other interactions in the community, as if the "profession" of the species.

Niche ecological fundamental(potential) is an ecological niche in which a species can exist in the absence of competition from other species.

Ecological niche realized (real) – ecological niche, part of a fundamental (potential) niche that a species can defend in competition with other species.

According to the relative position of the niches of the two types, they are divided into three types: non-contiguous ecological niches; contiguous but not overlapping niches; contiguous and overlapping niches.

Man is one of the representatives of the animal kingdom, a biological species of the class of mammals. Despite the fact that it has many specific properties (mind, articulate speech, labor activity, biosociality, etc.), it has not lost its biological essence and all the laws of ecology are valid for it to the same extent as for other living organisms. . Man has his own, only his own, ecological niche. The space in which the human niche is localized is very limited. As a biological species, humans can only live on land equatorial belt(tropics, subtropics), where the family of hominids arose.

1. Formulate the fundamental law of Gause. What is a "life form"? What ecological (or life) forms are distinguished among the inhabitants aquatic environment?

Both in the plant and in the animal world, interspecific and intraspecific competition is very widespread. There is a fundamental difference between them.

Rule (or even law) Gause: two species cannot occupy the same ecological niche at the same time and therefore necessarily crowd out each other.

In one of the experiments, Gause bred two types of ciliates - Paramecium caudatum and Paramecium aurelia. As food, they regularly received one of the types of bacteria that does not multiply in the presence of paramecium. If each type of ciliate was cultivated separately, then their populations grew according to a typical sigmoid curve (a). At the same time, the number of paramecia was determined by the amount of food. But when coexisting, paramecia began to compete, and P. aurelia completely replaced its competitor (b).

Rice. Competition between two closely related species of ciliates occupying a common ecological niche. a - Paramecium caudatum; b - P. aurelia. 1. - in one culture; 2. - in a mixed culture

With the joint cultivation of ciliates, after a while only one species remained. At the same time, ciliates did not attack individuals of another type and did not emit harmful substances. The explanation lies in the fact that the studied species differed in unequal growth rates. In the competition for food, the fastest breeding species won.

When breeding P. caudatum and P. bursaria there was no such displacement, both species were in equilibrium, the latter being concentrated on the bottom and walls of the vessel, and the former in free space, i.e., in another ecological niche. Experiments with other types of ciliates have demonstrated the regularity of the relationship between prey and predator.

Gauze principle is called the principle elimination competitions. This principle leads either to the ecological separation of closely related species, or to a decrease in their density where they are able to coexist. As a result of competition, one of the species is ousted. The Gause principle plays a huge role in the development of the concept of a niche, and also forces ecologists to look for answers to a number of questions: How do similar species coexist? How big must be the differences between species in order for them to coexist? How do you avoid competitive exclusion?

The life form of the species it is a historically developed complex of its biological, physiological and morphological properties, which determines a certain reaction to the influence of the environment.

Among the inhabitants of the aquatic environment (hydrobionts), the classification distinguishes the following life forms.

1.Neuston(from the Greek neuston - able to swim) – collection of marine and freshwater organisms that live near the surface of the water , for example, mosquito larvae, many protozoa, water strider bugs, and from plants, the well-known duckweed.

2. Closer to the surface of the water inhabits plankton.

Plankton(from Greek planktos - soaring) - floating organisms capable of making vertical and horizontal movements mainly in accordance with the movement of water masses. Allocate phytoplankton photosynthetic free-swimming algae and zooplankton- small crustaceans, larvae of mollusks and fish, jellyfish, small fish.

3.Nekton(from the Greek nektos - floating) - free-floating organisms capable of independent vertical and horizontal movement. Nekton lives in the water column - these are fish, in the seas and oceans, amphibians, large aquatic insects, crustaceans, and reptiles ( sea ​​snakes and turtles) and mammals: cetaceans (dolphins and whales) and pinnipeds (seals).

4. Periphyton(from Greek peri - around, about, phyton - plant) - animals and plants attached to the stems of higher plants and rising above the bottom (molluscs, rotifers, bryozoans, hydras, etc.).

5. Benthos ( from the Greek benthos - depth, bottom) - benthic organisms leading an attached or free lifestyle, including: living in the thickness of the bottom sediment. These are mainly molluscs, some lower plants, crawling insect larvae, and worms. The bottom layer is inhabited by organisms that feed mainly on decaying remains.

1. What is biocenosis, biogeocenosis, agrocenosis? The structure of biogeocenosis. Who is the founder of the doctrine of biocenosis? Examples of biogeocenoses.

Biocenosis(from Greek koinos - common bios - life) is a community of interacting living organisms, consisting of plants (phytocenosis), animals (zoocenosis), microorganisms (microbocenosis) adapted to coexist in a given territory.

The concept of "biocenosis" - conditional, since organisms cannot live outside the environment of existence, but it is convenient to use it in the process of studying ecological relationships between organisms. Depending on the area, the attitude to human activity, the degree of saturation, usefulness, etc. there are biocenoses of land, water, natural and anthropogenic, saturated and unsaturated, full-membered and non-full-membered.

Biocenoses, like populations - this is a supra-organismal level of life organization, but of a higher rank.

The sizes of biocenotic groups are different- these are also large communities of lichen pillows on tree trunks or a rotting stump, but this is also a population of steppes, forests, deserts, etc.

The community of organisms is called biocenosis, and the science that studies the community of organisms - biocenology.

V.N. Sukachev the term has been proposed (and generally accepted) to refer to communities biogeocenosis(from Greek bios - life, geo - Earth, cenosis - community) - is a collection of organisms natural phenomena characteristic of a given geographic area.

The structure of biogeocenosis includes two components biotic - community of living plant and animal organisms (biocenosis) - and abiotic - a set of non-living environmental factors (ecotope, or biotope).

Space with more or less homogeneous conditions, which occupies a biocenosis, is called a biotope (topis - place) or ecotope.

Ecotop includes two main components: climatetop- the climate in all its diverse manifestations and edaphotop(from the Greek edafos - soil) - soil, relief, water.

Biogeocenosis\u003d biocenosis (phytocenosis + zoocenosis + microbocenosis) + biotope (climatotop + edaphotop).

Biogeocenoses - these are natural formations (they contain the element "geo" - the Earth ) .

Examples biogeocenoses there may be a pond, a meadow, a mixed or single-species forest. At the level of biogeocenosis, all processes of transformation of energy and matter in the biosphere take place.

Agrocenosis(from Latin agraris and Greek koikos - common) - a community of organisms created by man and artificially supported by him with increased productivity (productivity) of one or more selected plant or animal species.

Agrocenosis differs from biogeocenosis main components. It cannot exist without human support, as it is an artificially created biotic community.

1. The concept of "ecosystem". Three principles of functioning of ecosystems.

ecological system- one of the most important concepts of ecology, abbreviated as an ecosystem.

Ecosystem(from the Greek oikos - dwelling and system) - this is any community of living beings, together with their habitat, connected inside complex system relationships.

Ecosystem - these are supraorganismal associations, including organisms and inanimate (inert) environment, which are in interaction, without which it is impossible to maintain life on our planet. This is a community of plant and animal organisms and an inorganic environment.

Based on the interaction of living organisms that form an ecosystem, between themselves and their environment, in any ecosystem, mutually dependent aggregates are distinguished biotic(living organisms) and abiotic(oblique or inanimate nature) components, as well as environmental factors (such as solar radiation, humidity and temperature, Atmosphere pressure), anthropogenic factors other.

To abiotic components of ecosystems include inorganic substances - carbon, nitrogen, water, atmospheric carbon dioxide, minerals, organic substances found mainly in the soil: proteins, carbohydrates, fats, humic substances, etc., which have entered the soil after the death of organisms.

To the biotic components of the ecosystem include producers, autotrophs (plants, chemosynthetics), consumers (animals) and detritophages, decomposers (animals, bacteria, fungi).

Kazan physiological school. F.V. Ovsyannikov, N.O. Kovalevsky, N.A. Mislavsky, A.V. Kibyakov

In the process of evolution, as a result of natural selection and the struggle for existence, adaptations (adaptations) of organisms to certain living conditions arise. Evolution itself is essentially a continuous process of formation of adaptations, occurring according to the following scheme: reproduction intensity -> struggle for existence -> selective death -> natural selection-> fitness.

Adaptations affect different aspects of the life processes of organisms and therefore can be of several types.

Morphological adaptations

They are associated with a change in the structure of the body. For example, the appearance of membranes between the toes in waterfowl (amphibians, birds, etc.), a thick coat in northern mammals, long legs and a long neck in marsh birds, a flexible body in burrowing predators (for example, in weasels), etc. In warm-blooded animals, when moving north, an increase in the average body size (Bergmann's rule) is noted, which reduces the relative surface and heat transfer. In bottom fish, a flat body is formed (stingrays, flounder, etc.). Plants in the northern latitudes and high mountain regions often have creeping and cushion-shaped forms, less damaged by strong winds and better warmed by the sun in the soil layer.

Protective coloration

Protective coloration is very important for animal species that do not have effective means of protection against predators. Thanks to her, animals become less visible on the ground. For example, female birds hatching eggs are almost indistinguishable from the background of the area. Bird eggs are also colored to match the color of the area. Bottom fish, most insects and many other animal species have a protective coloration. In the north, white or light coloration is more common, helping to camouflage in the snow ( polar bears, polar owls, polar foxes, cubs of pinnipeds - pups, etc.). A number of animals developed a coloration formed by alternating light and dark stripes or spots, making them less noticeable in bushes and dense thickets (tigers, young wild boars, zebras, spotted deer, etc.). Some animals are able to change color very quickly depending on the conditions (chameleons, octopuses, flounder, etc.).

Disguise

The essence of disguise is that the shape of the body and its color make animals look like leaves, knots, branches, bark or thorns of plants. Often found in insects that live on plants.

Warning or threatening coloration

Some types of insects that have poisonous or odorous glands have a bright warning color. Therefore, predators that once encountered them remember this color for a long time and no longer attack such insects (for example, wasps, bumblebees, ladybugs, Colorado beetles and a number of others).

Mimicry

Mimicry is the coloring and body shape of harmless animals that mimics their venomous counterparts. For example, some non-venomous snakes look like poisonous ones. Cicadas and crickets resemble large ants. Some butterflies have large spots on their wings that resemble the eyes of predators.

Physiological adaptations

This type of adaptation is associated with the restructuring of metabolism in organisms. For example, the emergence of warm-bloodedness and thermoregulation in birds and mammals. In simpler cases, this is an adaptation to certain forms of food, the salt composition of the environment, high or low temperatures, humidity or dryness of soil and air, etc.

Biochemical adaptations

Behavioral adaptations

This type of adaptation is associated with a change in behavior in certain conditions. For example, caring for offspring leads to better survival of young animals and increases the resilience of their populations. V mating periods many animals form separate families, and in winter they unite in flocks, which facilitates their food or protection (wolves, many species of birds).

Adaptations to periodic environmental factors

These are adaptations to environmental factors that have a certain periodicity in their manifestation. This type includes daily alternations of periods of activity and rest, states of partial or complete anabiosis (dropping leaves, winter or summer diapauses of animals, etc.), animal migrations caused by seasonal changes, etc.

Adaptations to extreme living conditions

Plants and animals that live in deserts and polar regions also acquire a number of specific adaptations. In cacti, the leaves have evolved into spines (to reduce evaporation and protect against being eaten by animals), and the stem has evolved into a photosynthetic organ and reservoir. Desert plants are long root system allowing water to be extracted from great depths. Desert lizards can survive without water by eating insects and obtaining water by hydrolyzing their fats. In northern animals, in addition to thick fur, there is also a large supply of subcutaneous fat, which reduces body cooling.

Relative nature of adaptations

All adaptations are expedient only for certain conditions in which they have developed. When these conditions change, adaptations can lose their value or even harm the organisms that have them. The white color of hares, which protects them well in the snow, becomes dangerous during winters with little snow or strong thaws.

relative nature adaptations are also well proven by paleontological data, which testify to the extinction of large groups of animals and plants that did not survive the change in living conditions.