Morphological and behavioral adaptations. Behavioral adaptations of organisms to the action of ecological factors. Examples. What is meant by adaptation

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 territorial features do not allow migration (islands, mountain plateaus, etc.). For a certain kind the changed living conditions still remain more suitable than in any other place. And physiological adaptation is the best option problem solving.

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. Conditions underlie the genotypic natural selection and mutations that have led to changes in the organisms of an entire species or population. It was in the process of this type of adaptation that the modern views animals, birds and humans. 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 habituation of the body to low temperatures with 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.

Based on the positive cross adaptations a set of measures has been developed to strengthen the heart muscle and prevent heart attacks. AT vivo those people who more often in life faced with stressful situations are less prone to the consequences of myocardial infarction than those who led a quiet 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 in cellular level. They characterize the formation of the degree of resistance of the organism to the effects negative factor environment. For example, change 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 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 body provide it with high level survival in adverse conditions and at abrupt changes in the habitat.

Such an observation is interesting. In animals of the northern populations, all elongated parts of the body - limbs, tail, ears - are covered with a dense layer of wool and look relatively shorter than in representatives of the same species, but living in a hot climate.

This pattern, known as the Alain rule, applies to both wild and domestic animals.

There is a noticeable difference in the body structure of the northern fox and the fennec fox in the south, the northern wild boar and the wild boar in the Caucasus. Mongrel domestic dogs in Krasnodar Territory, cattle of local selection are distinguished by a lower live weight compared to representatives of these species, say, Arkhangelsk.

Often animals from the southern populations of long-legged and long-eared. Large ears, unacceptable at low temperatures, arose as an adaptation to life in a hot zone.

And the animals of the tropics have just huge ears(elephants, rabbits, ungulates). Indicative ears African elephant, whose area is 1/6 of the surface of the entire body of the animal. They have abundant innervation and vascularity. In hot weather, about 1/3 of the entire circulating blood passes through the circulatory system of the ear shells in an elephant. As a result of increased blood flow in external environment excess heat is given off.

The desert hare Lapus alleni is even more impressive with its adaptive abilities to high temperatures. In this rodent, 25% of the entire body surface falls on bare auricles. It is not clear what the main biological task of such ears is: to detect the approach of danger in time or to participate in thermoregulation. Both the first and the second task are solved by the animal very effectively. The rodent has a keen ear. Developed circulatory system auricles with a unique vasomotor ability serves only thermoregulation. By increasing and limiting blood flow through the auricles, the animal changes heat transfer by 200-300%. Its hearing organs perform the function of maintaining thermal homeostasis and saving water.

Due to the saturation of the auricles with thermosensitive nerve endings and rapid vasomotor reactions from the surface of the auricles, a large number of excess thermal energy in the elephant, and especially in the lepus.

Fits well into the context of the problem under discussion and the structure of the body of a relative modern elephants- mammoth. This northern analogue of the elephant, judging by the preserved remains found in the tundra, was much larger than its southern relative. But the ears of the mammoth had a smaller relative area and, moreover, were covered with thick hair. The mammoth had relatively short limbs and a short trunk.

Long limbs are unfavorable at low temperatures, since too much thermal energy is lost from their surface. But in hot climates, long limbs are a useful adaptation. In desert conditions, camels, goats, horses of local selection, as well as sheep, cats, as a rule, have long legs.

According to H. Hensen, as a result of adaptation to low temperatures in animals, the properties of subcutaneous fat and bone marrow change. In arctic animals, bone fat from the phalanx of the fingers has low point melting and does not freeze even in severe frosts. However, bone fat from bones that do not come into contact with a cold surface, such as femur, has the usual physical and chemical properties. Liquid fat in the bones of the lower extremities provides thermal insulation and joint mobility.

The accumulation of fat is noted not only in northern animals, for which it serves as a thermal insulation and a source of energy during a period when food is not available due to severe bad weather. Fat accumulate and animals living in hot climates. But the quality, quantity and distribution of body fat in northern and southern animals is different. In wild arctic animals, fat is distributed evenly throughout the body in the subcutaneous tissue. In this case, the animal forms a kind of heat-insulating capsule.

In animals of the temperate zone, fat as a heat insulator accumulates only in species with a poorly developed coat. In most cases, stored fat serves as a source of energy during the hungry winter (or summer) period.

In hot climates, subcutaneous fat deposits carry a different physiological burden. The distribution of body fat throughout the body of animals is characterized by great unevenness. Fat is localized in the upper and back parts of the body. For example, in ungulates African savannas the fatty subcutaneous layer is localized along the spine. It protects the animal from the scorching sun. The belly is completely free of fat. It also has great sense. Ground, grass or water, which is colder than air, ensures efficient heat removal through the abdominal wall in the absence of fat. small body fat and in animals in hot climates, they are a source of energy for a period of drought and the hungry existence of herbivores associated with it.

The internal fat of animals in a hot and arid climate performs another extremely useful function. In conditions of lack or complete absence of water, internal fat serves as a source of water. Special studies show that the oxidation of 1000 g of fat is accompanied by the formation of 1100 g of water.

An example of unpretentiousness in the arid conditions of the desert are camels, fat-tailed and fat-tailed sheep, and zebu-like cattle. The mass of fat accumulated in the humps of a camel and the fat tail of a sheep is 20% of their live weight. Calculations show that a 50-kilogram fat-tailed sheep has a water supply of about 10 liters, and a camel even more - about 100 liters. The last examples illustrate the morphophysiological and biochemical adaptations of animals to extreme temperatures. Morphological adaptations spread to many organs. Northern animals have a large volume gastrointestinal tract and a large relative length of the intestine, they deposit more internal fat in the omentums and the perirenal capsule.

Animals of the arid zone have a number of morphological and functional features of the system of urination and excretion. As early as the beginning of the 20th century. morphologists have discovered differences in the structure of the kidneys of desert animals and animals temperate climate. In hot climate animals, the medulla is more developed due to an increase in the rectal tubular part of the nephron.

For example, at African lion the thickness of the renal medulla is 34 mm, while in the domestic pig it is only 6.5 mm. The ability of the kidneys to concentrate urine is positively correlated with the length of the loop of Hendle.

In addition to structural features in animals of the arid zone, functional features of the urinary system were found. So, for a kangaroo rat, a pronounced ability is normal Bladder reabsorb water from secondary urine. In the ascending and descending channels of the loop of Hendle, urea is filtered - a process common to the nodule part of the nephron.

The adaptive functioning of the urinary system is based on neurohumoral regulation with a pronounced hormonal component. In kangaroo rats, the concentration of the hormone vasopressin is increased. So, in the urine of a kangaroo rat, the concentration of this hormone is 50 U / ml, in a laboratory rat - only 5-7 U / ml. In the pituitary tissue of a kangaroo rat, the content of vasopressin is 0.9 U/mg, in a laboratory rat it is three times less (0.3 U/mg). Under water deprivation, differences between animals persist, although the secretory activity of the neurohypophysis increases in both one and the other animal.

The loss of live weight during water deprivation in arid animals is lower. If a camel loses 2-3% of its live weight during a working day, receiving only low-quality hay, then a horse and a donkey under the same conditions will lose 6-8% of their live weight due to dehydration.

The temperature of the habitat has a significant effect on the structure skin animals. In cold climates, the skin is thicker, the coat is thicker, and there are downs. All this helps to reduce the thermal conductivity of the body surface. In animals of a hot climate, the opposite is true: thin skin, sparse wool, low heat-insulating properties of the skin as a whole.

If you find an error, please highlight a piece of text and click Ctrl+Enter.

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: intensity of reproduction -> 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 webbing between the toes in waterfowl (amphibians, birds, etc.), a thick coat in northern mammals, long legs and long neck in wading 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 (Bergman's rule) is noted, which reduces the relative surface and heat transfer. In bottom fish, a flat body is formed (stingrays, flounder, etc.). In plants in northern latitudes and high mountainous areas, often creeping and pillow-shaped forms, less damaged 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 protection from 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, snowy owls, arctic foxes, cubs of pinnipeds - white 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 are not Poisonous snakes similar to poisonous. 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. AT 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 have a long root system that allows them to extract water from great depth. 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 indicating extinction large groups animals and plants that have not survived the change in living conditions.

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. Yes, among marine mammals dolphins have the most advanced adaptations for rapid movement in aquatic environment: torpedo shape, special structure skin and subcutaneous tissue, which increases the streamlining of the body, and consequently, the speed of sliding in the water.

There are three main forms of manifestation of adaptations: anatomical-morphological, physiological and behavioral.

Anatomical and morphological adaptations are some kind of external and internal features in the structure of certain organs of plants and animals, allowing them to live in a certain environment with a certain combination environmental factors. In animals, they are often associated with lifestyle, the nature of nutrition. Examples:

· hard shell turtles, providing 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 viscosity internal environments and preventing 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 nerve elements and nerve cells cerebral cortex.

Example physiological adaptations are also 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 migrations 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 comfortable temperature until morning.

In areas with harsh climates, but snowy winters the temperature under the snow can be 15-18ºС higher than outside. It was calculated that 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 groups up to 20 individuals. A similar phenomenon has been described in rodents.

· Adaptive behavior may 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 adaptations such as the development of specialized parts oral apparatus adapted to sucking, the formation of search behavior to find the prey animal, as well as the development salivary glands special secrets that prevent clotting of sucked blood.

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 longitude of the day. 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% reach the Earth's surface sun rays. 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:

· Organisms short day- 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 to 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

test questions to 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

These are the optimal proportions of the body, the location and density of the hair or feather cover, etc. well-known appearance aquatic mammal- a dolphin. His movements are light and precise. self speed movement in water reaches 40 kilometers per hour. The density of water is 800 times that of air. The torpedo-shaped shape of the body avoids the formation of eddies of water flows around the dolphin.