Behavioral adaptations - these are the features of behavior developed in the process of evolution that allow them to adapt and survive in the given environmental conditions.
Typical example- winter dream of a bear.
Also examples are 1) the creation of shelters, 2) movement in order to select the optimum temperature conditions, especially in conditions of extreme t. 3) the process of tracking down and pursuing prey from predators, and from prey - in response reactions (for example, hiding).
common for animals way of adapting to bad times- migration. (Saiga saigas annually leave for the winter in the snowless southern semi-deserts, where winter grasses are more nutritious and accessible due to the dry climate. However, in summer, semi-desert herbage quickly burns out, therefore, during the breeding season, saigas move to more humid northern steppes).
Examples 4) behavior when searching for food and a sexual partner, 5) mating, 6) feeding offspring, 7) avoiding danger and protecting life in case of a threat, 8) aggression and threatening postures, 9) care for offspring, which increases the likelihood of cub survival, 10) uniting in flocks, 11) imitation of injury or death in the event of a threat of attack.
21. Life forms, as a result of the adaptation of organisms to the action of a complex of environmental factors. Classification of life forms of plants according to K.Raunkier, I.G.Serebryakov, animals according to D.N.Kashkarov.
The term "life form" was introduced in the 80s by E. Warming. He understood life form as "a form in which the vegetative body of a plant (individual) is in harmony with the external environment throughout its life, from cradle to coffin, from seed to death." This is a very deep definition.
Life forms as types of adaptive structures demonstrate: 1) a variety of ways to adapt different plant species even to the same conditions,
2) the possibility of similarity of these paths in plants that are completely unrelated, belonging to different species, genera, families.
-> The classification of life forms is based on the structure of vegetative organs and reflects II and convergent paths of ecological evolution.
According to Raunkier: applied his system to find out the relationship between life forms of plants and climate.
He singled out an important feature that characterizes the adaptation of plants to the transfer of an unfavorable season - cold or dry.
This sign is the position of the renewal buds on the plant in relation to the level of the substrate and snow cover. Raunkier attributed this to protecting the kidneys during unfavorable times of the year.
1)phanerophytes- the buds hibernate or endure the dry period "open", high above the ground (trees, shrubs, woody vines, epiphytes).
-> they are usually protected by special bud scales, which have a number of devices to preserve the growth cone and young leaf primordia enclosed in them from moisture loss.
2)chamephites- the buds are located almost at the level of the soil or not higher than 20-30 cm above it (shrubs, semi-shrubs, creeping plants). In cold and dead climates, these kidneys very often receive additional protection in winter, in addition to their own kidney scales: they hibernate under the snow.
3)cryptophytes- 1) geophytes - buds are located in the ground at a certain depth (they are divided into rhizomatous, tuberous, bulbous),
2) hydrophytes - buds hibernate under water.
4)hemicryptophytes- usually herbaceous plants; their renewal buds are at the level of the soil or are sunk very shallowly, in the litter formed by leaf waste - another additional "cover" for the buds. Among the hemicryptophytes, Raunkier distinguishes " irotogeiicryptophytes"with elongated shoots, dying off annually to the base, where the renewal buds are located, and rosette hemicryptophytes, in which shortened shoots can overwinter at the entire soil level.
5)terophytes- special group; these are annuals in which all vegetative parts die off by the end of the season and there are no overwintering buds - these plants renew the next year from seeds that overwinter or survive a dry period on the soil or in the soil.
According to Serebryakov:
Using and summarizing the classifications proposed at different times, he proposed to call a life form a kind of habitus - (characteristic form, appearance of an org-ma) of plant opgroups that arise as a result of growth and development in def conditions - as an expression adaptation to these conditions.
The basis of its classification is a sign of the lifespan of the whole plant and its skeletal axes.
A. Woody plants
1. Trees
2. Shrubs
3. Shrubs
B. Semi-woody plants
1.Subshrubs
2.Subshrubs
B. Ground grasses
1.Polycarpic herbs (perennial herbs, bloom many times)
2. Monocarpic herbs (live for several years, bloom once and die off)
D. Water grasses
1. Amphibious herbs
2.Floating and underwater grasses
The life form of a tree turns out to be an extrusion of adaptations to conditions that are most favorable for growth.
V forests of the humid tropics- the most tree species (up to 88% in the Amazon region of Brazil), and in the tundra and highlands there are no real trees. In the area of taiga forests trees are represented by only a few species. No more than 10–12% of the total number of species are trees and in the flora of the temperate forest zone of Europe.
According to Kashkarov:
I. Floating forms.
1. Purely aquatic: a) nekton; b) plankton; c) benthos.
2. Semi-aquatic:
a) diving b) not diving; c) only getting food from the water.
II. Burrowing forms.
1. Absolute excavators (who spend their whole lives underground).
2. Relative excavations (coming to the surface).
III. ground forms.
1. Not making holes: a) running; b) jumping; c) crawling.
2. Making holes: a) running; b) jumping; c) crawling.
3. Animals of rocks.
IV. Wood climbing forms.
1. Not descending from the trees.
2. Only climbing trees.
V. Air forms.
1. Obtaining food in the air.
2. Searching for food from the air.
In the external appearance of birds, their confinement to specific types of habitats and the nature of movement when obtaining food are manifested to a significant extent.
1) woody vegetation;
2) open land spaces;
3) swamps and shoals;
4) water spaces.
In each of these groups, specific forms are distinguished:
a) getting food by climbing (pigeons, parrots, woodpeckers, passerines)
b) foraging in flight (long-winged, in the forests - owls, nightjars, over water - tube-nosed);
c) feeding while moving on the ground (in open spaces - cranes, ostriches; forest - most chickens; in swamps and shallows - some passerines, flamingos);
d) those who obtain food by swimming and diving (loons, copepods, gooses, penguins).
22. The main environments of life and their characteristics: land-air and water.
ground-air- most animals and plants live.
It is characterized by 7 main abiotic factors:
1.Low air density makes it difficult to maintain the shape of the body and provokes the image of the support system.
EXAMPLE: 1. Aquatic plants do not have mechanical tissues: they appear only in terrestrial forms. 2. Animals must have a skeleton: a hydroskeleton (in roundworms), or an external skeleton (in insects), or an internal skeleton (in mammals).
The low density of the medium facilitates the movement of animals. Many terrestrial species are capable of flight.(birds and insects, but there are also mammals, amphibians and reptiles). The flight is associated with the search for prey or resettlement. The inhabitants of the land spread only on the Earth, which serves as their support and attachment point. In connection with active flight in such organisms modified forelimbs and developed pectoral muscles.
2) Mobility of air masses
*Provides the existence of aeroplankton. It consists of pollen, seeds and fruits of plants, small insects and arachnids, spores of fungi, bacteria and lower plants.
This ecological group of org-in adapted due to the large variety of wings, outgrowths, cobwebs, or due to very small sizes.
* method of pollination of plants by wind - anemophilia- Har-n for birches, firs, pines, nettles, grasses and sedges.
* settling with the help of the wind: poplars, birches, ash trees, lindens, dandelions, etc. The seeds of these plants have parachutes (dandelions) or wings (maple).
3) Low pressure, norm=760 mm. The pressure drops, compared with the aquatic habitat, are very small; thus, at h=5800 m it is only half of its normal value.
=> almost all land inhabitants are sensitive to strong pressure drops, i.e. they are stenobionts in relation to this factor.
The upper limit of life for most vertebrates is 6000 m, because pressure drops with height, which means that the solubility of o in the blood decreases. To maintain a constant concentration of O 2 in the blood, the respiratory rate must increase. However, we exhale not only CO2, but also water vapor, so frequent breathing should invariably lead to dehydration of the organism. This simple dependence is not characteristic only for rare species of organisms: birds and some invertebrates, ticks, spiders and springtails.
4) Gas composition has a high content of O 2: it is more than 20 times higher than in the aquatic environment. This allows the animals to have very high metabolic rates. Therefore, only on land could arise homoiothermy- the ability to maintain a constant t of the body due to internal energy. Thanks to homoithermy, birds and mammals can remain active in the most severe conditions.
5) Soil and relief are very important, first of all, for plants. For animals, the structure of the soil is more important than its chemical composition.
*For ungulates that make long migrations on dense ground, the adaptation is a decrease in the number of fingers and => a decrease in the S-support.
* For the inhabitants of free-flowing sands, an increase in Spov-ti support (fan-toed gecko) is characteristic.
* Soil density is also important for burrowing animals: prairie dogs, marmots, gerbils and others; some of them develop digging limbs.
6) Significant water shortage on land provokes the development of various adaptations aimed to conserve water in the body:
The development of respiratory organs capable of absorbing O 2 from the air environment of the integument (lungs, trachea, lung sacs)
Development of waterproof covers
The change will highlight the system and metabolic products (urea and uric acid)
Internal fertilization.
In addition to providing water, precipitation also plays an ecological role.
*Snow value reduces fluctuations in t at depths of 25 cm. Deep snow protects plant buds. For black grouse, hazel grouse and tundra partridges, snowdrifts are a place to spend the night, i.e. at 20–30 o below zero at a depth of 40 cm, it remains ~0 °С.
7) Temperature regime more variable than water. ->many land dwellers eurybiont to this f-ru, i.e., they are able to exist in a wide range of t and demonstrate very different ways of thermoregulation.
Many animal species that live in areas where winters are snowy molt in autumn, changing the color of their coat or feathers to white. It is possible that such a seasonal molt of birds and animals is also an adaptation - a camouflage coloration, which is typical for the hare, weasel, arctic fox, tundra partridge and others. However, not all white animals change color seasonally, which reminds us of the neopremism and the impossibility of considering all the properties of the body as beneficial or harmful.
Water. Water covers 71% of the S of the earth or 1370 m3. The main mass of water - in the seas and oceans - 94-98%, polar ice contains about 1.2% of water and a very small proportion - less than 0.5%, in fresh waters of rivers, lakes and swamps.
About 150,000 species of animals and 10,000 plants live in the aquatic environment, which is only 7 and 8% of the total number of species on Earth. So on land, evolution was much more intense than in water.
In the seas-oceans, as in the mountains, is expressed vertical zoning.
All inhabitants of the aquatic environment can be divided into three groups.
1) Plankton- countless accumulations of tiny organisms that cannot move on their own and are carried by currents in the top layer of sea water.
It consists of plants and living organisms - copepods, eggs and larvae of fish and cephalopods, + unicellular algae.
2) Nekton- a large number of org-in freely floating in the thickness of the oceans. The largest of them are blue whales and giant sharks that feed on plankton. But there are also dangerous predators among the inhabitants of the water column.
3) Benthos- the inhabitants of the bottom. Some deep-sea inhabitants are deprived of the organs of vision, but most can see in dim light. Many residents lead an attached lifestyle.
Adaptations of aquatic organisms to high water density:
Water has a high density (800 times the density of air) and viscosity.
1) Plants have very poorly developed or absent mechanical tissues- they are supported by the water itself. Most are buoyant. Har-but active vegetative reproduction, the development of hydrochory - the removal of flower stalks above the water and the spread of pollen, seeds and spores by surface currents.
2) The body has a streamlined shape and is lubricated with mucus, which reduces friction when moving. Adaptations for increasing buoyancy have been developed: accumulations of fat in tissues, swim bladders in fish.
In passively swimming animals - outgrowths, spikes, appendages; the body flattens, reduction of skeletal organs occurs.
Different modes of transportation: bending of the body, with the help of flagella, cilia, jet mode of locomotion (cephalomolluscs).
In benthic animals, the skeleton disappears or is poorly developed, the size of the body increases, the reduction of vision is common, and the development of tactile organs.
Adaptations of hydrobionts to water mobility:
Mobility is caused by ebbs and flows, sea currents, storms, different levels of elevations of river beds.
1) In flowing waters, plants and animals are firmly attached to stationary underwater objects.. The bottom surface for them is primarily a substrate. These are green and diatom algae, water mosses. Of the animals - gastropods, barnacles + hide in crevices.
2) Different body shapes. In fish flowing through the waters, the body is round in diameter, and in fish living near the bottom, the body is flat.
Adaptations of hydrobionts to water salinity:
Natural reservoirs are characterized by a certain chemical composition. (carbonates, sulfates, chlorides). In fresh water bodies, the salt concentration is not > 0.5 g /, in the seas - from 12 to 35 g / l (ppm). With a salinity of more than 40 ppm, the reservoir is called g hyperhaline or oversalted.
1) * In fresh water (hypotonic environment) osmoregulation processes are well expressed. Hydrobionts are forced to constantly remove the water penetrating into them, they homoiosmotic.
* In salt water (isotonic medium), the concentration of salts in the bodies and tissues of hydrobionts is the same as the concentration of salts dissolved in water - they poikiloosmotic. -> Inhabitants of salt water bodies have not developed osmoregulatory functions, and they could not populate fresh water bodies.
2) Aquatic plants are able to absorb water and nutrients from the water - "broth", the entire surface, therefore, their leaves are strongly dissected and conductive tissues and roots are poorly developed. The roots serve to attach to the underwater substrate.
Typically marine and typically freshwater species - stenohaline, cannot tolerate changes in salinity. Euryhaline species Little. They are common in brackish waters (pike, bream, mullet, coastal salmon).
Adaptation of hydrobionts to the composition of gases in water:
In water, O 2 is the most important environmental factor. Its source is atm-ra and photosynthetic plants.
When water is stirred and t decreases, the O 2 content increases. *Some fish are very sensitive to O2 deficiency (trout, minnow, grayling) and therefore prefer cold mountain rivers and streams.
*Other fish (crucian carp, carp, roach) are unpretentious to the content of O 2 and can live at the bottom of deep water bodies.
* Many aquatic insects, mosquito larvae, lung mollusks are also tolerant to the content of O 2 in water, because from time to time they rise to the earth and swallow fresh air.
There is enough carbon dioxide in water - almost 700 times more than in air. It is used in plant photosynthesis and goes to the formation of calcareous skeletal formations of animals (mollusk shells).
Living organisms are adapted to the environmental conditions in which their ancestors lived for a long time. Adaptations to environmental conditions are otherwise called adaptations. They arise in the process of population evolution, forming a new subspecies, species, genus, etc. Different genotypes accumulate in the population, manifested in different phenotypes. Those phenotypes that are most suitable for environmental conditions are more likely to survive and leave offspring. Thus, the entire population is “saturated” with adaptations that are useful for a given habitat.
According to their forms (types) of adaptation are different. They can affect the structure of the body, behavior, appearance, cell biochemistry, etc. There are the following forms of adaptations.
Body structure adaptations (morphological adaptations). There are significant (at the level of orders, classes, etc.) and small (at the level of species). Examples of the former are the appearance of wool in mammals, the ability to fly in birds, and the lungs in amphibians. An example of minor adaptations is the different structure of the beak in closely related bird species that feed in different ways.
Physiological adaptations. This is a metabolic restructuring. For each species, adapted to its habitat conditions, its own metabolic characteristics are characteristic. So some species eat a lot (for example, birds), because their metabolism is quite fast (birds need a lot of energy to fly). Some species may not drink for a long time (camels). Marine animals can drink sea water, while freshwater and terrestrial animals cannot.
biochemical adaptations. This is a special structure of proteins, fats, giving organisms the opportunity to live in certain conditions. For example, at low temperatures. Or the ability of organisms to produce poisons, toxins, odorous substances for protection.
Protective coloration. Many animals in the process of evolution acquire a body color that makes them less noticeable against the background of grass, trees, soil, that is, where they live. This allows some to protect themselves from predators, others to sneak up unnoticed and attack. Often, young mammals and chicks have protective coloration. While adults may no longer have a protective coloration.
Warning (threatening) coloration. This coloring is bright and well-remembered. Characteristic of stinging and poisonous insects. For example, birds do not eat wasps. Having tried once, they remember the characteristic color of the wasp for the rest of their lives.
Mimicry- external resemblance to poisonous or stinging species, dangerous animals. Allows you to avoid being eaten by predators who "seem" that they are facing a dangerous species. So hover flies look like bees, some non-venomous snakes on poisonous ones, on the wings of butterflies there can be patterns similar to the eyes of predators.
Disguise- the similarity of the shape of the body of an organism with an object of inanimate nature. Here, not only a protective coloration arises, but the organism itself in its form resembles an object of inanimate nature. For example, a branch, a leaf. Camouflage is mainly characteristic of insects.
Behavioral adaptations. Each species of animals develops a special type of behavior that allows them to best adapt to specific living conditions. This includes food storage, care for offspring, mating behavior, hibernation, hiding before an attack, migration, etc.
Often different adaptations are interconnected. For example, protective coloration can be combined with the animal freezing (with behavioral adaptation) at the moment of danger. Also, many morphological adaptations are due to physiological ones.
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 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, arctic foxes, pinniped cubs - 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 potato 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. During the mating season, 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 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.
The relative nature of adaptations is 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.
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 on from one generation to the next, remaining relatively unchanged, so that representatives of one species or another 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 large 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 the head allows them to assess 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.
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.
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