Type of adaptation characteristic examples. Behavioral adaptations of organisms to the action of ecological factors. Examples. Why Physiological Adaptation Is Necessary
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.
- 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. The species adapted to low temperatures is cryophilic(from the Greek krios - cold), and to high temperatures - thermophilic. Similar patterns apply to other factors as well. Plants can be hydrophilic, i.e. demanding on water and xerophilic(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.
- 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 the doctrine of the external forms of 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, movement in the direction of more favorable, preferred temperature conditions, the choice of places with optimal humidity or light. 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 strength 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 .
- 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 - this is a population in which the number of individuals of different ages varies evenly and has the character of a normal distribution (as an 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.
- 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 of 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 environment and others like them.
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. the adaptability of a species to a certain 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, a person can live only within the land of the equatorial belt (tropics, subtropics), where the hominid family arose.
- Formulate the fundamental law of Gause. What is a "life form"? What ecological (or life) forms are distinguished among the inhabitants of the 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 no such displacement occurred, 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 a different 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 so that they can 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, also reptiles (sea snakes and turtles) and mammals: cetaceans (dolphins and whales) and pinnipeds (seals).
4. Periphyton(from the 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.
- What is biocenosis, biogeocenosis, agrocenosis? The structure of biogeocenosis. Who is the founder of the doctrine of biocenosis? Examples of biogeocenoses.
Biocenosis(from the Greek koinos - common bios - life) is a community of interacting living organisms, consisting of plants (phytocenosis), animals (zoocenosis), microorganisms (microbocenosis) adapted to cohabitation 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, attitude to human activity, 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) - it is a set of organisms and natural phenomena characteristic of a given geographical 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.
- 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 by a complex system of 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, with each other and with their habitat, in any ecosystem, interdependent aggregates are distinguished biotic(living organisms) and abiotic(inert or inanimate nature) components, as well as environmental factors (such as solar radiation, humidity and temperature, atmospheric pressure), anthropogenic factors other.
To abiotic components of ecosystems include inorganic substances - carbon, nitrogen, water, atmospheric carbon dioxide, minerals, organic substances that are predominantly in the soil: proteins, carbohydrates, fats, humic substances, etc., that enter 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).
The textbook complies with the Federal State Educational Standard for Secondary (Complete) General Education, is recommended by the Ministry of Education and Science of the Russian Federation and is included in the Federal List of Textbooks.
The textbook is addressed to students in grade 11 and is designed to teach the subject 1 or 2 hours per week.
Modern design, multi-level questions and tasks, additional information and the possibility of parallel work with an electronic application contribute to the effective assimilation of educational material.
Rice. 33. Winter coloring of a hare
So, as a result of the action of the driving forces of evolution, organisms develop and improve adaptations to environmental conditions. Fixation in isolated populations of various adaptations can eventually lead to the formation of new species.
Review questions and assignments
1. Give examples of the adaptability of organisms to the conditions of existence.
2. Why do some animals have a bright, unmasking color, while others, on the contrary, are patronizing?
3. What is the essence of mimicry?
4. Does the action of natural selection extend to the behavior of animals? Give examples.
5. What are the biological mechanisms for the emergence of adaptive (concealing and warning) coloration in animals?
6. Are physiological adaptations factors that determine the level of fitness of the organism as a whole?
7. What is the essence of the relativity of any adaptation to living conditions? Give examples.
Think! Execute!
1. Why is there no absolute adaptation to living conditions? Give examples proving the relative nature of any device.
2. Boar cubs have a characteristic striped coloration that disappears with age. Give similar examples of color changes in adults compared to offspring. Can this pattern be considered common to the entire animal world? If not, for which animals and why is it typical?
3. Gather information about warning color animals in your area. Explain why knowledge of this material is important for everyone. Make an information stand about these animals. Give a presentation on this topic in front of elementary school students.
Work with computer
Refer to the electronic application. Study the material and complete the assignments.
Repeat and remember!
Person
Behavioral adaptations are innate unconditioned reflex behavior. Innate abilities exist in all animals, including humans. A newborn baby can suck, swallow and digest food, blink and sneeze, react to light, sound and pain. These are examples unconditioned reflexes. Such forms of behavior arose in the process of evolution as a result of adaptation to certain, relatively constant environmental conditions. Unconditioned reflexes are inherited, so all animals are born with a ready-made complex of such reflexes.
Each unconditioned reflex occurs to a strictly defined stimulus (reinforcement): some to food, others to pain, others to the appearance of new information, etc. The reflex arcs of unconditioned reflexes are constant and pass through the spinal cord or brain stem.
One of the most complete classifications of unconditioned reflexes is the classification proposed by Academician P. V. Simonov. The scientist proposed to divide all unconditioned reflexes into three groups, differing in the features of the interaction of individuals with each other and with the environment. Vital reflexes(from lat. vita - life) are aimed at preserving the life of the individual. Failure to comply with them leads to the death of the individual, and the implementation does not require the participation of another individual of the same species. This group includes food and drink reflexes, homeostatic reflexes (maintaining a constant body temperature, optimal breathing rate, heart rate, etc.), defensive ones, which, in turn, are divided into passive-defensive (runaway, hiding) and active defensive (attack on a threatening object) and some others.
To zoosocial, or role-playing reflexes include those variants of innate behavior that arise when interacting with other individuals of their species. These are sexual, parent-child, territorial, hierarchical reflexes.
The third group is reflexes of self-development. They are not connected with adaptation to a specific situation, but, as it were, turned to the future. Among them are exploratory, imitative and playful behavior.
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Animals and plants are forced to adapt to many factors, and these adaptations are developed over a certain period of time, often in the process of evolution and natural selection, being fixed at the genetic level.
Adaptation(from lat. adapto - I adapt) - adaptations of the structure and functions of organisms to environmental conditions in the process of evolution.
When analyzing the organization of any animal and plant, a striking correspondence of the form and functions of the organism to environmental conditions is always found. So, among marine mammals dolphins they have the most advanced adaptations for rapid movement in the aquatic environment: a torpedo-shaped shape, a special structure of the skin and subcutaneous tissue, which increases the streamlining of the body, and, consequently, the speed of sliding in water.
There are three main forms of manifestation of adaptations: anatomical-morphological, physiological and behavioral.
Anatomical and morphological adaptations are some external and internal features in the structure of certain organs of plants and animals that allow them to live in a certain environment with a certain combination of environmental factors. In animals, they are often associated with lifestyle, the nature of nutrition. Examples:
Hard tortoise shell for protection from predatory animals
Woodpecker - chisel-shaped beak, hard tail, characteristic arrangement of fingers.
Physiological adaptations consist in the ability of organisms to change some of their physiological processes during critical periods in their life
· The smell of the flower can serve to attract insects and thereby promote pollination of the plant.
· Deep dormancy in many plants growing in the middle latitudes of the northern hemisphere, falling into a stupor or hibernation in some animals with the onset of a cold period).
· Biological antifreezes that increase the viscosity of internal media and prevent the formation of ice crystals that would destroy cells (up to 10% in ants, up to 30% in wasps).
In the dark, the sensitivity of the eye to light increases many thousands of times within an hour, which is associated both with the restoration of sight, pigments, and with changes in the nerve elements and nerve cells of the cerebral cortex.
· An example of physiological adaptations are also the features of the enzymatic set in the digestive tract of animals, determined by the set and composition of food. Thus, desert dwellers are able to provide their need for moisture by biochemical oxidation of fats.
Behavioral(ethological) adaptations are forms of adaptive behavior of animals. Examples:
· To ensure normal heat exchange with the environment: the creation of shelters, daily and seasonal migration of animals in order to select the optimal temperature conditions.
Hummingbird Oreotrochis estella, living in the high Andes, builds nests on the rocks, and on the side facing the East. During the night, the stones give off the heat accumulated during the day, thereby providing a comfortable temperature until the morning.
· In areas with a harsh climate, but snowy winters, the temperature under the snow can be 15-18ºС higher than outside. It is estimated that the white partridge, spending the night in a snowy hole, saves up to 45% of energy.
Many animals use group roosting: pikas of the genus Certhia(birds) gather in cold weather in groups of up to 20 individuals. A similar phenomenon has been described in rodents.
· Adaptive behavior can appear in predators in the process of tracking and chasing prey.
Most adaptations is a combination of the above types. For example, bloodsucking in mosquitoes is provided by a complex combination of such adaptations as the development of specialized parts of the oral apparatus adapted for sucking, the formation of search behavior to find a prey animal, and the production of special secretions by the salivary glands that prevent the blood being sucked from clotting.
One of the fundamental properties of living nature is the cyclicity of most of the processes occurring in it, which ensures the adaptation of plants and animals during their development with the main periodic factors. Let us dwell on such a phenomenon in wildlife as photoperiodism.
Photoperiodism - response of organisms to seasonal changes in day length. Opened by V. Garner and N. Allard in 1920 during selection work with tobacco.
Light has a leading influence on the manifestation of daily and seasonal activity of organisms. This is an important factor, since it is the change in illumination that causes the alternation of a period of rest and intensive life activity, many biological phenomena in plants and animals (that is, it affects the biorhythm of organisms).
For example, 43% of the sun's rays reach the Earth's surface. Plants are able to capture from 0.1 to 1.3%. They absorb the yellow-green spectrum.
And a signal of the approach of winter for plants and animals is a decrease in the length of the day. Plants undergo a gradual physiological restructuring, the accumulation of a supply of energy substances before winter dormancy. By photoperiodic reaction plant organisms are divided into two groups:
Short-day organisms - flowering and fruiting occurs at 8-12 hours of light (buckwheat, millet, hemp, sunflower).
long day organisms. For flowering and fruiting in long-day plants, it is necessary to lengthen the day to 16-20 hours (plants of temperate latitudes), for which a decrease in day length to 10-12 hours is a signal of the approach of an unfavorable autumn-winter period. These are potatoes, wheat, spinach.
· Neutral to length for the plant. Flowering occurs at any length of the day. These are dandelion, mustard and tomato.
The same is found in animals. During the day, the activity of each organism falls on certain hours. The mechanisms that allow organisms to change their state cyclically are called "biological clocks".
Bibliographic list for the section
1. Galperin, M.V. General ecology: [proc. for avg. prof. education] / M.V. Galperin. - M. : Forum: Infra-M, 2006. - 336 p.
2. Korobkin, V.I. Ecology [Text] / V.I. Korobkin, L.V. Peredelsky. - Rostov-on-Don: Phoenix, 2005. - 575 p.
3. Mirkin, B.M. Fundamentals of general ecology [Text]: textbook. allowance for university students studying natural sciences. specialties / B.M. Mirkin, L.G. Naumov; [ed. G.S. Rosenberg]. - M. : Univ. book, 2005. - 239 p.
4. Stepanovskikh, A.S. General ecology: [proc. for universities on ecol. specialties] / A.S. Stepanovsky. - 2nd ed., add. and reworked. - M. : UNITI, 2005. - 687 p.
5. Furyaev, V.V. General ecology and biology: textbook. allowance for students of the specialty 320800 pts. forms of education / V.V. Furyaev, A.V. Furyaev; Feder. education agency, Sib. state technol. un-t, Institute of Forests named after. V. N. Sukacheva. - Krasnoyarsk: SibGTU, 2006. - 100 p.
6. Golubev, A.V. General ecology and environmental protection: [proc. manual for all specialties] / A.V. Golubev, N.G. Nikolaevskaya, T.V. Sharapa; [ed. ed.] ; State. educate. institution of higher prof. Education "Moscow. state. un-t forest". - M. : MGUL, 2005. - 162 p.
7. Korobkin, V.I. Ecology in questions and answers [Text]: textbook. allowance for university students / V.I. Korobkin, L.V. Peredelsky. - 2nd ed., revised. and additional - Rostov n / a: Phoenix, 2005. - 379 p. : schemes. - Bibliography: p. 366-368. - 103.72 rubles
Security questions for section 3
1. The concept of habitat, its types.
2. What are environmental factors, how are they classified?
3. The concept of a limiting factor, examples.
4. The law of optimum-pessimum (figure). Examples.
5. Law of interaction of environmental factors. Examples.
6. The law of tolerance (Shelford). Examples.
7. Environmental rules: D. Allen, K. Bergman, K. Gloger.
8. Adaptations of living organisms, their ways and forms. Examples.
9. Photoperiodism, biological rhythms: concept, examples.
SECTION 4: POPULATION ECOLOGY
To survive in adverse climatic conditions, plants, animals and birds have some features. These features are called "physiological adaptations," examples of which can be seen in virtually every mammalian species, including humans.
Why do we need physiological adaptation?
Living conditions in some parts of the world are not entirely comfortable, however, there are various representatives of wildlife. There are several reasons why these animals did not leave the hostile environment.
First of all, climatic conditions could change when a certain species already existed in a given area. Some animals are not adapted to migration. It is also possible that the territorial features do not allow migration (islands, mountain plateaus, etc.). For a certain species, the changed living conditions still remain more suitable than in any other place. And physiological adaptation is the best solution to the problem.
What is meant by adaptation?
Physiological adaptation is the harmony of organisms with a specific habitat. For example, a comfortable stay in the desert of its inhabitants is due to their adaptation to high temperatures and lack of access to water. Adaptation is the appearance of certain signs in organisms that allow them to get along with any elements of the environment. They arise in the process of certain mutations in the body. Physiological adaptations, examples of which are well known in the world, are, for example, the ability to echolocation in some animals (bats, dolphins, owls). This ability helps them navigate in a space with limited lighting (in the dark, in water).
Physiological adaptation is a set of body reactions to certain pathogenic factors in the environment. It provides organisms with a greater likelihood of survival and is one of the methods of natural selection of strong and resistant organisms in a population.
Types of physiological adaptation
Adaptation of the organism is distinguished genotypic and phenotypic. The genotypic is based on the conditions of natural selection and mutations that led to changes in the organisms of a whole species or population. It was in the process of this type of adaptation that the modern species of animals, birds and humans were formed. The genotypic form of adaptation is hereditary.
The phenotypic form of adaptation is due to individual changes in a particular organism for a comfortable stay in certain climatic conditions. It can also develop due to constant exposure to an aggressive environment. As a result, the body acquires resistance to its conditions.
Complex and cross adaptations
Complex adaptations are manifested in certain climatic conditions. For example, the body's adaptation to low temperatures during a long stay in the northern regions. This form of adaptation develops in each person when moving to another climatic zone. Depending on the characteristics of a particular organism and its health, this form of adaptation proceeds in different ways.
Cross-adaptation is a form of body habituation in which the development of resistance to one factor increases the resistance to all factors of this group. The physiological adaptation of a person to stress increases his resistance to some other factors, such as cold.
On the basis of positive cross-adaptations, a set of measures was developed to strengthen the heart muscle and prevent heart attacks. Under natural conditions, those people who more often faced stressful situations in their lives are less susceptible to the consequences of myocardial infarction than those who led a calm lifestyle.
Types of adaptive reactions
There are two types of adaptive reactions of the body. The first type is called "passive adaptations". These reactions take place at the cellular level. They characterize the formation of the degree of resistance of the organism to the effects of a negative environmental factor. For example, a change in atmospheric pressure. Passive adaptation allows you to maintain the normal functionality of the body with small fluctuations in atmospheric pressure.
The most well-known physiological adaptations in animals of the passive type are the protective reactions of the living organism to the effects of cold. Hibernation, in which life processes slow down, is inherent in some species of plants and animals.
The second type of adaptive reactions is called active and implies protective measures of the body when exposed to pathogenic factors. In this case, the internal environment of the body remains constant. This type of adaptation is inherent in highly developed mammals and humans.
Examples of physiological adaptations
The physiological adaptation of a person is manifested in all non-standard situations for his environment and lifestyle. Acclimatization is the most famous example of adaptations. For different organisms, this process takes place at different speeds. Some take a few days to get used to the new conditions, for many it will take months. Also, the rate of habituation depends on the degree of difference with the habitual environment.
In aggressive habitats, many mammals and birds have a characteristic set of body reactions that make up their physiological adaptation. Examples (in animals) can be observed in almost every climate zone. For example, desert dwellers accumulate reserves of subcutaneous fat, which oxidizes and forms water. This process is observed before the onset of the drought period.
Physiological adaptation in plants also takes place. But she is passive. An example of such an adaptation is the shedding of leaves by trees when the cold season sets in. The places of the kidneys are covered with scales, which protect them from the harmful effects of low temperatures and snow with wind. Metabolic processes in plants slow down.
In combination with morphological adaptation, the physiological reactions of the organism provide it with a high level of survival in adverse conditions and with drastic changes in the environment.
Morphological adaptations involve changes in the shape or structure of an organism. An example of such an adaptation is the hard shell, which provides protection from predatory animals. Physiological adaptations are associated with chemical processes in the body. Thus, the smell of a flower can serve to attract insects and thus contribute to the pollination of a plant. Behavioral adaptation is associated with a certain aspect of the animal's life. A typical example is a bear's winter sleep. Most adaptations are a combination of these types. For example, bloodsucking in mosquitoes is provided by a complex combination of such adaptations as the development of specialized parts of the oral apparatus adapted for sucking, the formation of search behavior to find a prey animal, and the production of special secretions by the salivary glands that prevent the blood being sucked from clotting.
All plants and animals are constantly adapting to their environment. To understand how this happens, it is necessary to consider not only the animal or plant as a whole, but also the genetic basis of adaptation.
genetic basis.
In each species, the program for the development of traits is embedded in the genetic material. The material and the program encoded in it are passed from one generation to another, remaining relatively unchanged, due to which representatives of one or another species look and behave almost the same. However, in a population of organisms of any kind, there are always small changes in the genetic material and, therefore, variations in the characteristics of individual individuals. It is from these diverse genetic variations that the process of adaptation selects or favors the development of those traits that most increase the chances of survival and thereby the preservation of genetic material. Adaptation can thus be seen as the process by which genetic material improves its chances of being retained in subsequent generations. From this point of view, each species represents a successful way of preserving a certain genetic material.
In order to pass on genetic material, an individual of any species must be able to feed, survive to a breeding season, leave offspring, and then spread it over as wide a territory as possible.
Nutrition.
All plants and animals must receive energy and various substances from the environment, primarily oxygen, water and inorganic compounds. Almost all plants use the energy of the Sun, transforming it in the process of photosynthesis. Animals get energy by eating plants or other animals.
Each species is adapted in a certain way to provide itself with food. Hawks have sharp claws for grasping prey, and the location of their eyes in front of their heads allows them to judge the depth of space, which is necessary for hunting when flying at high speed. Other birds, such as herons, have developed long necks and legs. They forage for food by cautiously roaming the shallow waters and lying in wait for gaping aquatic animals. Darwin's finches, a group of closely related bird species from the Galapagos Islands, are a classic example of highly specialized adaptations to different diets. Due to certain adaptive morphological changes, primarily in the structure of the beak, some species became granivorous, while others became insectivorous.
If we turn to fish, then predators, such as sharks and barracudas, have sharp teeth for catching prey. Others, such as small anchovies and herring, obtain small food particles by filtering seawater through comb-shaped gill rakers.
In mammals, an excellent example of adaptation to the type of food are the features of the structure of the teeth. The fangs and molars of leopards and other felines are extremely sharp, which allows these animals to hold and tear the victim's body. In deer, horses, antelopes and other grazing animals, large molars have wide ribbed surfaces, adapted for chewing grass and other plant foods.
A variety of ways to obtain nutrients can be observed not only in animals, but also in plants. Many of them, primarily legumes - peas, clover and others - have developed symbiotic, i.e. mutually beneficial relationship with bacteria: bacteria convert atmospheric nitrogen into a chemical form available to plants, and plants provide energy to bacteria. Insectivorous plants, such as sarracenia and sundew, obtain nitrogen from the bodies of insects caught by trapping leaves.
Protection.
The environment consists of living and non-living components. The living environment of any species includes animals that feed on individuals of that species. The adaptations of carnivorous species are geared towards efficient foraging; prey species adapt so as not to become the prey of predators.
Many species - potential prey - have a protective or camouflage coloration that hides them from predators. So, in some species of deer, the spotted skin of young individuals is invisible against the background of alternating spots of light and shadow, and it is difficult to distinguish white hares against the background of snow cover. The long thin bodies of stick insects are also difficult to see because they resemble knots or twigs of bushes and trees.
Deer, hares, kangaroos, and many other animals have evolved long legs to enable them to run away from predators. Some animals, such as opossums and pig-faced snakes, have even developed a peculiar way of behavior - imitation of death, which increases their chances of survival, since many predators do not eat carrion.
Some types of plants are covered with thorns or thorns that scare away animals. Many plants have a disgusting taste to animals.
Environmental factors, in particular climatic ones, often put living organisms in difficult conditions. For example, animals and plants often have to adapt to temperature extremes. Animals escape the cold by using insulating fur or feathers by migrating to warmer climates or hibernating. Most plants survive the cold by going into a state of dormancy, equivalent to hibernation in animals.
In hot weather, the animal is cooled by sweating or frequent breathing, which increases evaporation. Some animals, especially reptiles and amphibians, are able to hibernate in summer, which is essentially the same as winter hibernation, but caused by heat rather than cold. Others are just looking for a cool place.
Plants can maintain their temperature to some extent by regulating the rate of evaporation, which has the same cooling effect as perspiration in animals.
Reproduction.
A critical step in ensuring the continuity of life is reproduction, the process by which genetic material is passed on to the next generation. Reproduction has two important aspects: the meeting of heterosexual individuals for the exchange of genetic material and the rearing of offspring.
Among the adaptations that ensure the meeting of individuals of different sexes is sound communication. In some species, the sense of smell plays an important role in this sense. For example, cats are strongly attracted to the smell of a cat in estrus. Many insects secrete the so-called. attractants - chemicals that attract individuals of the opposite sex. Flower scents are effective plant adaptations to attract pollinating insects. Some flowers are sweet-smelling and attract nectar-feeding bees; others smell disgusting, attracting carrion flies.
Vision is also very important for meeting individuals of different sexes. In birds, the mating behavior of the male, his lush feathers and bright coloring, attracts the female and prepares her for copulation. Flower color in plants often indicates which animal is needed to pollinate that plant. For example, flowers pollinated by hummingbirds are colored red, which attracts these birds.
Many animals have developed ways to protect their offspring during the initial period of life. Most adaptations of this kind are behavioral and involve actions by one or both parents that increase the chances of survival of the young. Most birds build nests specific to each species. However, some species, such as the cowbird, lay their eggs in the nests of other bird species and entrust the young to the parental care of the host species. Many birds and mammals, as well as some fish, have a period when one of the parents takes great risks, taking on the function of protecting offspring. Although this behavior sometimes threatens the death of the parent, it ensures the safety of the offspring and the preservation of the genetic material.
A number of species of animals and plants use a different reproduction strategy: they produce a huge number of offspring and leave them unprotected. In this case, the low chances of survival for an individual growing individual are balanced by the large number of offspring.
Resettlement.
Most species have developed mechanisms for removing offspring from the places where they were born. This process, called dispersal, increases the likelihood that offspring will grow up in an unoccupied territory.
Most animals simply avoid places where there is too much competition. However, evidence is accumulating that dispersal is due to genetic mechanisms.
Many plants have adapted to seed dispersal with the help of animals. So, cocklebur seedlings have hooks on the surface, with which they cling to the hair of animals passing by. Other plants produce tasty fleshy fruits, such as berries, which are eaten by animals; the seeds pass through the digestive tract and are "sown" intact elsewhere. Plants also use the wind to propagate. For example, the "propellers" of maple seeds are carried by the wind, as well as the seeds of the cottonwort, which have tufts of fine hairs. Steppe plants of the tumbleweed type, acquiring a spherical shape by the time the seeds ripen, are distilled by the wind over long distances, dispersing the seeds along the way.
The above were just some of the most striking examples of adaptations. However, almost every sign of any species is the result of adaptation. All these signs make up a harmonious combination, which allows the body to successfully lead its special way of life. Man in all his attributes, from the structure of the brain to the shape of the big toe, is the result of adaptation. Adaptive traits contributed to the survival and reproduction of his ancestors who had the same traits. In general, the concept of adaptation is of great importance for all areas of biology.
