Biochemical adaptation characteristics and examples. Types of adaptation: morphological, physiological and behavioral adaptation

a brown or green twig, and orthoptera insects imitate a leaf. Fish that lead a bottom-dwelling lifestyle (for example, flounder) have a flat body.

Protective coloration

Allows you to be invisible among the surrounding background. Thanks to the protective coloration, the organism becomes difficult to distinguish and, therefore, protected from predators. Bird eggs laid on sand or ground are gray and brown with spots, similar to the color of the surrounding soil. In cases where eggs are inaccessible to predators, they are usually colorless. Butterfly caterpillars are often green, the color of the leaves, or dark, the color of the bark or earth. Bottom fish usually colored to match the color of the sandy bottom (rays and flounder). Moreover, flounders also have the ability to change color depending on the color of the surrounding background. The ability to change color by redistributing pigment in the integument of the body is also known in terrestrial animals (chameleon). Desert animals, as a rule, have a yellow-brown or sandy-yellow color. A monochromatic protective color is characteristic of both insects (locusts) and small lizards, as well as large ungulates (antelope) and predators (lion).

Warning coloring

Warns a potential enemy of the presence defense mechanisms(availability toxic substances or special protection bodies). Warning coloring distinguishes poisonous, stinging animals and insects (snakes, wasps, bumblebees) from the environment with bright spots or stripes.

Mimicry

Mimicry is the result of homologous (identical) mutations in different types, which help unprotected animals survive. For imitating species, it is important that their numbers are small compared to the model they are imitating, otherwise the enemies will not develop a stable negative reflex to the warning coloration. The low number of mimicking species is supported by a high concentration of lethal genes in the gene pool. When homozygous, these genes cause lethal mutations, resulting in a high percentage of individuals not surviving to adulthood.

Basically, adaptation systems in one way or another relate to cold, which is quite logical - if you manage to survive in deep minus, other dangers will not be so terrible. The same, by the way, applies to extreme high temperatures. Those who are able to adapt will most likely not disappear anywhere.

Arctic hare are the largest hares North America, who for some reason have relatively short ears. This is a great example of what an animal can sacrifice to survive in harsh conditions- Although long ears can help to hear a predator; short ones reduce the transfer of precious heat, which is much more important for Arctic hare.

Frogs from Alaska of the species Rana sylvatica, perhaps, even surpassed Antarctic fish. They literally freeze into the ice in winter, thus waiting out the cold season, and come back to life in the spring. Such “cryosleep” is possible for them thanks to special structure the liver, which doubles in size during hibernation, and the complex biochemistry of the blood.

Some species of mantises, unable to stay in the sun all day long, cope with the problem of lack of heat with the help of chemical reactions in your own body, concentrating flashes of heat inside for short-term heating.

A cyst is a temporary form of existence of bacteria and many single-celled organisms, in which the body surrounds itself with a dense protective shell to protect itself from aggressive external environment. This barrier is very effective - in some cases it can help the owner survive for a couple of decades.

Nototheniform fish live in the waters of Antarctica, so cold that ordinary fish they would freeze to death there. sea ​​water freezes only at a temperature of -2°C, which cannot be said about completely fresh blood. But Antarctic fish secrete a natural antifreeze protein that prevents ice crystals from forming in the blood - and survive.

Megathermia is the ability to generate heat using body mass, thereby surviving in cold conditions even without antifreeze in the blood. Some people use this sea ​​turtles, remaining mobile when the water around almost freezes.

Asian bar-headed geese, when crossing the Himalayas, rise to enormous heights. The highest flight of these birds was recorded at an altitude of 10 thousand meters! Geese have complete control over their body temperature, even changing it if necessary. chemical composition blood to survive in the icy and thin air.

Mudskippers are not the most common type of fish, although they are fairly commonplace gobies. At low tide, they crawl through the mud, getting food for themselves, sometimes climbing trees. In their way of life, mudskippers are much closer to amphibians, and only fins with gills reveal them as fish.

Adaptations (devices)

Biology and genetics

The relative nature of adaptation: corresponding to a specific habitat, adaptations lose their significance when it changes; the hare is delayed in winter or during a thaw. early spring noticeable against the background of arable land and trees; aquatic plants die when water bodies dry up, etc. Examples of adaptation Type of adaptation Characteristics of adaptation Examples Special shape and structure of the body Streamlined body shape gills fins Pinniped fish Protective coloring Can be solid or dismembered; is formed in organisms living openly and makes them invisible...

Adaptations

Adaptation (or adaptation) is a complex of morphological, physiological, behavioral and other characteristics of an individual, population or species that ensures success in competition with other individuals, populations or species and resistance to environmental factors.

■ Adaptation is the result of the action of evolutionary factors.

The relative nature of adaptation: corresponding to a specific habitat, adaptations lose their significance when it changes (the white hare, when winter is delayed or during a thaw, is noticeable in early spring against the background of arable land and trees; aquatic plants die when water bodies dry out, etc.).

Examples of adaptation

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The textbook is addressed to 11th grade students and is designed to teach the subject 1 or 2 hours a week.

Modern design, multi-level questions and tasks, additional information and the possibility of parallel work with an electronic application contribute to the effective assimilation of educational material.

Rice. 33. Winter coloring of a hare

So, as a result of the action driving forces evolution, organisms develop and improve adaptations to environmental conditions. Establishment in isolated populations various adaptations may eventually lead to the formation of new species.

Review questions and assignments

1. Give examples of the adaptation of organisms to living conditions.

2. Why do some animals have bright, unmasking colors, while others, on the contrary, have protective colors?

3. What is the essence of mimicry?

4. Does natural selection apply to animal behavior? Give examples.

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

6. Are physiological adaptations factors that determine the level of fitness of the organism as a whole?

7. What is the essence of the relativity of any adaptation to living conditions? Give examples.

Think! Do it!

1. Why is there no absolute adaptation to living conditions? Give examples to prove relative character any device.

2. Boar cubs have a characteristic striped coloring, which disappears with age. Give similar examples of color changes in adults compared to offspring. Can this pattern be considered common to the entire animal world? If not, then for which animals and why is it characteristic?

3. Gather information about animals with warning colors that live in your area. Explain why knowledge of this material is important for everyone. Make an information stand about these animals. Give a presentation on this topic to primary school students.

Working with a computer

Refer to the electronic application. Study the material and complete the assignments.

Human

Behavioral adaptations are innate, unconditional reflex behavior. Innate abilities exist in all animals, including humans. A newborn baby can suck, swallow and digest food, blink and sneeze, react to light, sound and pain. These are examples unconditioned reflexes. Such forms of behavior arose in the process of evolution as a result of adaptation to certain, relatively constant environmental conditions. Unconditioned reflexes are inherited, so all animals are born with a ready-made complex of such reflexes.

Each unconditioned reflex occurs in response to a strictly defined stimulus (reinforcement): some - to food, others - to pain, others - to the appearance of new information etc. The reflex arcs of unconditioned reflexes are constant and pass through the spinal cord or brain stem.

One of the most complete classifications of unconditioned reflexes is the classification proposed by Academician P. V. Simonov. The scientist suggested dividing everything unconditioned reflexes into three groups, differing in the characteristics of the interaction of individuals with each other and with environment. Vital reflexes(from Latin vita - life) are aimed at preserving the life of the individual. Failure to comply with them leads to the death of the individual, and implementation does not require the participation of another individual of the same species. This group includes food and drinking reflexes, homeostatic reflexes (maintaining a constant body temperature, optimal frequency breathing, heartbeat, etc.), defensive, which, in turn, are divided into passive-defensive (running away, hiding) and active-defensive (attacking a threatening object) and some others.

TO zoosocial, or role-playing reflexes include those variants of innate behavior that arise during interaction with other individuals of their own species. These are sexual, child-parent, territorial, hierarchical reflexes.

The third group is self-development reflexes. They are not related to adaptation to a specific situation, but seem to be directed to the future. These include exploratory, imitative and playful behavior.