Adaptive features of the structure of the body color and behavior of animals, as a result of the action of natural selection. Biology at the Lyceum Presentations adaptive behavior of humans and animals

Summary of a lesson in biology Grade 9

Topic: "Adaptive features of the structure, body color and behavior of animals"

Textbook: "Biology General Patterns Grade 9" S.G. Mamontov, V.B. Zakharov, N.I. Sonin

biology teacher MBOU secondary school No. 37 Lukyanenko A.S.

Target: to get acquainted with different types of adaptability of living organisms to the environment, to understand the relative nature of fitness.

Tasks:

to continue the formation of ecological culture among schoolchildren, the belief in the need to preserve the species diversity of plants and animals. draw conclusions about the natural causes of the formation of adaptations, using the doctrine of the driving forces of evolution; broaden the horizons of students.

№ lesson

during the classes

1. Actualization of previous knowledge

K.O.Z.

What forces of evolution have we met?

What force of evolution did Charles Darwin consider to be the main one?

Which organisms survive and reproduce as a result of natural selection?

What do you think can be done to adapt to the environment?

K.O.Z.

Let's remember such a force of evolution as the struggle for existence. What forms of struggle for existence do you know? What is the peculiarity of the interspecies struggle for existence, between whom does it take place? how should predators and their prey adapt?

solid broken

SLIDE #13-14warning coloration However, often in animals there is a body color that does not hide, but, on the contrary, attracts attention, unmasks. This form of adaptation is called warning coloring. It is characteristic of most stinging, poisonous, disgusting-smelling or disgusting-tasting animals. Like stoplights, these patterns and color combinations should be easily recognized by the animals. They mean: "Dangerous!", "Don't come near!", "It's better not to mess with me!". A ladybug, very noticeable, is never pecked by birds because of the poisonous secret secreted by insects. Inedible caterpillars, many poisonous snakes have a bright warning color. Among amphibians there are real dandies. They are spectacularly coloured, often slow, diurnal, and do not even try to hide from predators, unlike their more numerous camouflaged relatives, who go in search of food at night, when they are less visible. The most peculiar among amphibian dandies are, perhaps, poison dart frogs, inhabitants of Central and South America. Their skin glands produce powerful paralyzing poisons, so that a predator that has tried to eat such a frog and survived, associates the experienced unpleasant moments with its bright colors and in the future diligently avoids its like. Among the approximately one hundred thousand species that make up the order of Lepidoptera, or butterflies, bears belong not only to the most familiar, but also to the most beautiful. She has an extremely effective warning coloration - orange-black and yellow-black with patterns of spots and stripes. The bear is very pretty, but poisonous. Special glands produce strong toxins that enter the butterfly's bloodstream. Other glands contain a liquid with an unpleasant warning odor. In the tropical coastal waters of Australia, New Guinea, Indonesia and the Philippines, a small (up to 20 cm long with tentacles) blue-ringed octopus lives. Bright orange round spots are bordered by characteristic blue rings. Like all representatives of the genus, the blue-ringed octopus has an amazing ability to regenerate, and, having lost one or more of its eight tentacles in battle, it can quickly grow new ones. As beautiful as this octopus is, it is also poisonous. Animal saliva contains the strongest neurotoxin. The bite of the blue-ringed octopus is deadly. The poison almost instantly paralyzes the nervous system of any living creature, and there is no antidote for it.SLIDE No.mimicry The effectiveness of warning coloring was the cause of a very interesting phenomenon - imitation, or mimicry. Mimicry is the imitation of a less protected organism of one species to a more protected organism of another species. This imitation can manifest itself in body shape, coloration, and so on. Covered with warning stripes, but completely harmless, the hoverfly fly extracts nectar from the flower, as do honey bees, which have a formidable sting. Hoverfly mimicry is not limited to coloration, but includes behavior as well. Hoverflies imitate the sounds made by bees and wasps and, if disturbed, buzz menacingly. All this together guarantees immunity to the hoverfly. The beautiful butterfly danaid owes its inedibility to the fact that its caterpillars feed on the leaves of poisonous lettuce, which is dangerous for livestock and other vertebrates. Winged predators quickly learned not to touch the danaids, and at the same time their imitator, one of the nymphalids - only slightly tasteless. The glass butterfly is surprisingly similar to a wasp. Its wings are completely transparent, since it does not have scales covering the wings of butterflies. When flying, it buzzes like wasps, and flies as swiftly and restlessly as they do. Already imitates the color of the viper, it is given out only by yellow spots on the head. Many imitators have acquired venomous coral snakes. For example, the Arizona king snake, which is not venomous.SLIDE No. disguise In animals leading a hidden, hiding way of life, adaptations are useful that give them a resemblance to environmental objects - disguise. For example, moth butterfly caterpillars resemble knots in body shape and color. Stick insects look like a small brown or green twig, some butterflies look like dried leaves, and spiders look like thorns. The great masters of disguise owe much of their success to their ability to freeze at the moment when they are threatened with an attack or they themselves are preparing to seize the prey. Among animals, those who in one way or another imitate flowers are especially diverse. For example, flower praying mantises are so similar to one or another part of the plant that other insects, deceived by the similarity, descend directly on them and fall into the arms of a predator.Students write definitions and draw conclusions about the relative nature of any adaptation..

K.O.Z. How do such perfect adaptations come about? The clue lies in the complex process of natural selection. For example, the distant ancestor of a butterfly, now almost indistinguishable from a dry leaf, came into the world with a random set of genes that made it look a little more like a dry leaf. Therefore, it was somewhat more difficult for the birds to find this butterfly among the dry leaves, and as a result, she and her like individuals survived in greater numbers. Consequently, they left more offspring. And the sign of “dry leaf” became more and more clear and common. All traits are the result of mutations. One large mutation can occur, or a huge number of small ones, which happens much more often. Those that increase vitality are passed on to subsequent generations, fixed and become adaptations. Each adaptation is developed on the basis of hereditary variability in the process of struggle for existence and selection in a number of generations.

What conclusions can be drawn from all of the above?

1. The general adaptability of organisms to environmental conditions consists of many individual adaptations of very different scales.2. All adaptations arise in the course of evolution as a result of natural selection.3.Any fit is relative.Thus, fitness is the relative expediency of the structure and functions of an organism, which is the result of natural selection.

Reflection D.Z.

slide 1

slide 2

slide 3

slide 4

slide 5

slide 6

Slide 7

Slide 8

Slide 9

slide 10

slide 11

slide 12

slide 13

slide 14

slide 15

slide 16

slide 17

slide 18

slide 19

slide 20

slide 21

slide 22

slide 23

slide 24

slide 25

It leads to the fact that only species that have adapted to external conditions survive in nature. It operates not only at the level of populations, but also at the level of individuals. The adaptive behavior and structure of living organisms is the basis of adaptive changes.

patronizing color

Animals that lead an open lifestyle and do not use natural shelters have a camouflage color of their covers. Protective coloration can be observed in the tundra partridge. She is constantly at risk of being eaten by predators. In summer, the birds have a brown and red color, which makes them invisible against the background of stone placers. In winter, after molting, it changes to white. Males change color to summer later than females, this is necessary to divert the attention of predators from females hatching chicks.

Most representatives of the polar fauna have white covers: the polar owl, arctic fox, hare, polar bear, etc. The caterpillars are colored in the color of the foliage or branches along which they move. Benthic organisms have a brownish tint, making them invisible against the background of bottom sediments. Flounders are able to adjust the color to the color of the soil.

Such dynamic changes occur as a result of the redistribution of skin pigments. Among land animals, the most famous camouflage is the chameleon.

The stripes and spots found in large animals also serve as camouflage. They imitate a shadow, make the outline of the animal more blurred.

Adaptive body shape

Adaptive animal behavior is not the only way to survive. The shape of the body is also an evolutionary achievement, helping to adapt to the conditions of the surrounding world.

Dolphin is a famous aquatic animal with a memorable body shape. The speed of movement in the aquatic environment, which is eight hundred times denser than air, reaches forty kilometers per hour. The dolphins managed to reduce the resistance of the environment by acquiring a streamlined shape and the absence of auricles. Most aquatic inhabitants have similar adaptations: whales, seals, fish.

The streamlined body shape of birds reduces the amount of energy required for flight and allows for greater speed. In terms of speed, they have no equal in the animal kingdom.
The adaptive shape of the body helps animals to disguise themselves. The moth caterpillar moves along the branches and outwardly resembles a small twig. Some arachnids look like thorny parts of plants, and butterflies look like yellowed leaves.

Together with a camouflage color, animals are characterized by the ability to freeze before a throw to prey or in a moment of danger. Representatives of the fauna, like flowers, are distinguished by the greatest variety of shapes and colors. The similarity is so great that some insects sit right on them, mistaking them for a plant.

Warning coloration of covers

The adaptive features of the structure, color and behavior of animals are so diverse that their classification should be considered conditional. Often animals do not have a masking color of the covers, but a bright and noticeable one. It has creatures that can sting, poison or have a vile taste. The purpose of this color is to warn the predator: "I'm dangerous! I'm not tasty! Don't touch me!".

The ladybug is able to secrete a secret dangerous for birds and warns them with its bright color. There are noticeable colors in poisonous snakes and caterpillars. Some amphibians with a bright appearance are clumsy, active during the day and do not hide from enemies. And their relatives, on the contrary, have a protective color of covers and move at night. One of the most dangerous amphibians is poison dart frogs. Their skin secret is able to paralyze a predator.

The bear butterfly is distinguished by a bright pattern on its wings, which warns predators of the toxicity of a potential prey. In addition to the toxins contained in the blood, the insect emits a bad smell.

The blue-ringed octopus, which lives in tropical waters, has such a beautiful appearance and strong poison that one bite is enough to kill the victim. There is no antidote for the strongest neurotoxin.

Mimicry

Warning coloration has proven so effective that a number of species have taken advantage of it. A living creature imitates a poisonous and dangerous representative of another taxon with its appearance. This phenomenon is called mimicry.

External similarity is achieved not only due to color, but also to the shape of the body. The hoverfly has yellow and black stripes, but is completely defenseless, unlike the bee. The insect also has adaptive behavior, with which it copies the actions of a dangerous double:

• Collects nectar from flowers.
• When flying, it makes bee-like sounds.
• When threatened, it buzzes like a bee.

The combination of behavior and color is a guarantee of immunity for the hoverfly.

Adaptive Behavior: Animal Examples

Organisms are trying to survive, adaptive behavior plays an important role in this. The behavior of living organisms changes at the moment of danger:

• The geese hiss with their necks stretched out.
• Cats arch their backs and lift their tails, their hair standing up.
• The wolves show their grins.
• Toads straighten their hind limbs.
• The skunk first tramples, and then, with its tail up, splashes a jet of liquid with an unpleasant odor.
• The bombardier beetle shoots venom that causes burns. A "haze" appears from the jet in the air, which allows the insect to hide.

All of these species have their own adaptive features of the structure and behavior. Animals need it to survive.

Food storage

Defense against enemies is not the only manifestation of adaptive behavior. An example is the creation of a reserve for food in an unfavorable period.
Chipmunk first tidies up in his pantry: he takes out the remnants of last year's stocks, and puts dry leaves on the floor. As provisions, he brings nuts, mushrooms and seeds, which he stacks separately from each other and carefully sorts. The amount of stored food can reach eight kilograms.

Other animals also have features of adaptive behavior: squirrels, jays, mice and predatory animals make caches with food for the winter period. Hibernation helps hedgehogs, badgers, ground squirrels and bears to survive the unfavorable months. They store nutrients inside the body, and then use them sparingly with a slow metabolism.

In late autumn, the bear acquires long thick hair and finds a place for wintering in the dense forest. He lines his bed with fallen leaves and moss. By this time, the owner of the taiga had already formed a sufficient layer of subcutaneous fat. Over time, the snow will sweep the bear, a den is formed that looks like a huge snowdrift. A dormant animal gradually consumes stored substances during the winter. The body temperature is reduced to thirty degrees.

Caring for offspring

To preserve the species, adaptation to protect the younger generation is of great importance. Fish drive away predators from spawning sites or carry it in the mouth. Male sticklebacks make a kind of nest for caviar. It has two openings for oxygen access.

In some species of frogs, the development of eggs is carried out in the pouch. Birds build nests, lay eggs and hatch chicks. After hatching, they are provided with food and protection, which is an adaptive feature of animal behavior.

Mammals not only feed and protect babies, but also pass on the skills of obtaining food to them.

Physiological adaptations

There are no trifles in the process of survival. For an animal, not only external signs and behavior are important, but also adaptation at the physiological level. Without it, the stability of metabolic processes in the body against the background of changing external conditions is under threat.

The accumulated subcutaneous fat helps living organisms in the desert for a long time to do without moisture. It is obtained by its oxidation. At the same time, water loss through evaporation is minimized.

Seals are able to dive to great depths, reaching 600 m. They hold their breath for up to one hour. This is possible thanks to myoglobin, which is found in muscle tissue. This pigment is able to bind oxygen by an order of magnitude more than hemoglobin. In owls, vision is adapted to the lack of light at night. Bats make their way in the dark using echolocation.

Representatives of the flora are also forced to adapt to external conditions. The leaves of cacti gradually changed into spines to reduce the area of ​​transpiration. The fleshy stem serves as a reservoir for moisture.

Huge leaves of water lilies, on the contrary, contribute to a high rate of transpiration in conditions of high humidity. Tundra vegetation has its own adaptations: low growth, small leaves, superficial root system, rapid development during the growing season.

Relativity of fixtures

The perfection of adaptations has been honed by centuries of natural selection, but none of them is perfect in everything. Each device helps a living organism only under certain conditions. If they change, then the sign becomes neutral or even dangerous for the individual himself.

The white partridge is given out by the shadow cast on the snow on a clear day. The hare after the autumn molt becomes noticeable against the background of dark trees. To take off, the swift needs to push off from the edge of the surface. Short legs and long wings prevent climbing from level ground.

The shell protects turtles from enemies, but birds of prey have learned to drop reptiles from great heights in order to break it. Rodent incisors grow non-stop, which is necessary to feed on solid food. If their diet consists only of soft food, then overgrown teeth will not allow them to eat.

Adaptations are the properties and characteristics of organisms that provide adaptation to the environment in which these organisms live. Adaptation is also called the process of adaptation.

How did all these amazing devices come about? It is unlikely that a single mutation could provide such a precise correspondence between an insect wing and a living leaf, between a fly and a bee. It's incredible that a single mutation would cause a patronizingly colored insect to hide on exactly the leaves it looks like. Obviously, such adaptations as protective and warning coloration and mimicry arose by the gradual selection of all those small deviations in body shape, in the distribution of certain pigments, in innate behavior that existed in the populations of the ancestors of these animals. One of the most important characteristics of natural selection is its cumulativeness - its ability to accumulate and strengthen these deviations in a number of generations, adding up changes in individual genes and the systems of organisms controlled by them. Kogan V.L. etc. Biology. M.., 2008. P.142.

The most interesting and difficult problem is the initial stages of the emergence of adaptations. It is clear what advantages the almost perfect resemblance of a praying mantis to a dry branch gives. But what advantages could his distant ancestor, who only remotely resembled a twig, have? Are predators so stupid that they can be fooled so easily? No, predators are by no means stupid, and natural selection from generation to generation "teaches" them to better and better recognize the tricks of their prey. Even the perfect resemblance of a modern praying mantis to a knot does not give him a 100% guarantee that not a single bird will ever notice him. However, its chances of eluding a predator are higher than those of an insect with a less perfect protective coloration. In the same way, his distant ancestor, who only slightly looks like a knot, had a slightly higher chance of life than his relative who did not look like a knot at all. Of course, the bird that sits next to him will easily notice him on a clear day. But if the day is foggy, if the bird does not sit nearby, but flies by and decides not to waste time on what may be a praying mantis, or may be a knot, then the minimal similarity saves the life of the bearer of this barely noticeable similarity. His descendants who inherit this minimal resemblance will be more numerous. Their share in the population will increase. This will make life difficult for the birds. Among them, those who will more accurately recognize camouflaged prey will become more successful.

Natural selection picks up all those minute changes that increase the similarity in color and shape with the substrate, the similarity between the edible species and the inedible species that it imitates. It should be borne in mind that different types of predators use different methods of finding prey. Some pay attention to shape, others to color, some have color vision, others do not. So natural selection automatically enhances, as far as possible, the similarity between imitator and model, and leads to those amazing adaptations that we see in nature. Kogan V. L. and others. Biology. M.., 2008. P.149.

The emergence of complex adaptations. Many adaptations come across as elaborate and purposefully planned devices. How could such a complex structure as the human eye have arisen by natural selection of randomly occurring mutations?

Scientists suggest that the evolution of the eye began with small groups of light-sensitive cells on the surface of the body of our very distant ancestors, who lived about 550 million years ago. The ability to distinguish between light and dark was certainly useful for them, increasing their chances of life compared to their completely blind relatives. An accidental curvature of the "visual" surface improved vision, this made it possible to determine the direction to the light source. An eyecup appeared. Newly emerging mutations could lead to narrowing and widening of the optic cup opening. The narrowing gradually improved vision - the light began to pass through a narrow aperture. As you can see, each step increased the fitness of those individuals that changed in the “right” direction. Light-sensitive cells formed the retina. Over time, a lens has formed in the front of the eyeball, which acts as a lens. It appeared, apparently, as a transparent two-layer structure filled with liquid.

All the supposed stages in the evolution of the human eye can be found among living animals. The evolution of the eye has followed different paths in different types of animals. Through natural selection, many different forms of the eye have independently evolved, and the human eye is only one of them, and not the most perfect.

If we carefully consider the construction of the eye of man and other vertebrates, we will find a number of strange inconsistencies. When light enters the human eye, it passes through the lens and onto the light-sensitive cells in the retina. Light has to travel through a dense network of capillaries and neurons to reach the photoreceptor layer. Surprisingly, but the nerve endings approach the photosensitive cells not from behind, but from the front! Moreover, the nerve endings are collected in the optic nerve, which extends from the center of the retina, and thus creates a blind spot. To compensate for the shadowing of photoreceptors by neurons and capillaries and get rid of the blind spot, our eye is constantly moving, sending a series of different projections of the same image to the brain. Our brain performs complex operations, adding these images, subtracting the shadows, and calculating the real picture. Kogan V.L. etc. Biology. M.., 2008. P.150.

Question 1. Give examples of the adaptability of organisms to the conditions of existence based on your own observations.

In the course of evolution, organisms acquire various properties that allow them to more successfully adapt to living conditions. For example, the fur of northern animals (arctic foxes, bears) is white, making them almost invisible against the background of snow. Insects that feed on flower nectar have a proboscis structure and length that is ideal for this. The seal flippers, modified from the paws of their land ancestors, are perfectly adapted to movement in the water. Giraffes live in the savannah and eat the leaves of trees at high altitudes, with the help of their long necks.

There are many such examples, since each living creature has a large number of features acquired in the process of adapting to specific living conditions.

Question 2. Why do some animals have a bright, unmasking color, while others, on the contrary, have a protective one?

Two types of coloring correspond to two variants of the strategy of behavior. In one of them, the animal tends to go unnoticed, trying to avoid a meeting with a predator or sneaking up on a prey. For this, a protective coloration is used to blend in with the background. On the other hand, animals that are dangerous or poisonous often emphasize this in every possible way. They use bright, unmasking coloration, warning "don't eat me." In addition to poisonous organisms, this strategy is used by harmless species mimicking for them. Organisms can have unmasking coloration for a completely different reason - in connection with the desire to attract a partner for reproduction (the bright color of many male birds, fish, reptiles, butterflies, etc.). In this case, the task of procreation comes into conflict with the instinct of self-preservation, but it turns out to be more significant for the organism.

Question 3. What is the essence of mimicry? Compare mimicry and disguise. What are their fundamental differences? How are they similar?

The essence of mimicry (from the Greek mimikos - imitative) lies in the fact that harmless animals in the process of evolution become similar to dangerous (poisonous) species. This allows them to avoid predation. Some non-poisonous snakes serve as an example: there is a species of snake that is similar in color to a deadly asp and differs from it only in the alternation of stripes. In addition to color, mimic animals have a characteristic behavior: hoverfly flies behave like wasps, imitating aggression.

Question 4. Does the action of natural selection extend to the behavior of animals? Give examples.

Natural selection affects not only the external signs of the organism, but also behavior. This applies, first of all, to innate (instinctive) forms of behavior. Such forms are very diverse: ways of obtaining food, manifestations of fear and aggression, sexual behavior, parental behavior, etc. The spider weaves a web, the bee builds honeycombs, the cat assumes a threatening posture at the moment of danger, chipmunks stock up and hibernate for the winter and etc. Very complex mating rituals, strict adherence to which is for animals one of the ways to prevent interspecific crossing.

Question 5. What are the biological mechanisms for the emergence of adaptive (concealing and warning) coloration in animals?

The biological mechanism that ensures the emergence of adaptive coloration is natural selection. In the process of evolution, in a population that, due to the diversity of the gene pool, was distinguished by a very wide range of colors, those individuals that were less noticeable against the background of the environment mainly survived and left offspring. As a result, the proportion of corresponding genotypes has steadily increased. Subsequently, this phenotype, and hence the genotype, was fixed in the population with the help of stabilizing selection. In the case of warning coloration, similar processes occurred. For example, birds initially find and eat bright insects more easily. If these insects turn out to be poisonous, then birds quickly learn not to touch them and prefer more modestly colored prey. Thus, individuals with a bright color, which is easy to identify as poisonous, are preserved and leave offspring. Over time, this trait is fixed in the population.

Question 6. Are there living organisms that do not have adaptive structural features? Justify the answer.

Adaptation is a set of features of the structure, physiology and behavior of living organisms to specific conditions in which they can normally exist and leave offspring.

The emergence of adaptability to the environment is the main result of evolution. Therefore, evolution can be seen as a process of adaptations or adaptations.

Organisms that failed to adapt to the environment died out.