Superorganic systems. The evolution of the organic world

Evolutionary doctrine

Basic concepts:

species, species criteria, population, taxonomy, classification, history of evolutionary ideas, synthetic theory of evolution, driving forces of evolution, forms of natural selection, population waves, gene drift, artificial selection, types of struggle for existence, results of evolution, microevolution, speciation, isolation, fitness, relative character of fitness, forms and directions of evolution, biological progress and regression, macroevolution, aromorphosis, idioadaptation, degeneration, evidence of evolution

There are about 2 million species of animals on Earth, more than 500 thousand species of plants, hundreds of thousands of species of fungi and microorganisms. A species is a collection of organisms that actually exist in nature.

View – it is a set of individuals, similar in structure, having a common origin, freely interbreeding with each other and giving fertile offspring. All individuals of the same species have the same karyotype - a set of chromosomes of a somatic cell (2n), similar behavior, occupy a certain territory - an area (from lat. Area - area, space). Karl Linnaeus (17th century) introduced the concept of "species".

A species is one of the main forms of organization of living things. Each type of living organism can be described based on a set of characteristic features, properties, which are called traits. The characteristics of a species by which one species is distinguished from another are called species criteria.

View criteria - a set of characteristic features, properties and features by which one species differs from another. The most commonly used six general species criteria are morphological, physiological, genetic, biochemical, geographic, and ecological. At the same time, none of the criteria is absolute; to determine the type, the presence of the maximum number of criteria is necessary.

Morphological criterion - a description of the external (morphological) characteristics and internal (anatomical) structure of individuals that are part of a particular species. In appearance, size and color of the plumage, one can, for example, easily distinguish the great spotted woodpecker from the green one, the great tit from the crested. By the appearance of shoots and inflorescences, the size and location of the leaves, the types of clover are easily distinguished: meadow and creeping. The morphological criterion is widely used in taxonomy. However, this criterion is insufficient to distinguish between species that have significant morphological similarity. For example, in nature there are sibling species that do not have noticeable morphological differences (black rats have two sibling species - with a set of chromosomes 38 and 42, and six similar species were previously called malaria mosquito, of which only one spreads malaria).

Physiological criterion lies in the similarity of life processes, primarily in the possibility of crossing between individuals of the same species with the formation of fertile offspring. There is physiological isolation between different species. At the same time, crossing is possible between some species of living organisms; in this case, fertile hybrids can form (canaries, hares, poplars, willows, etc.)

Geographic criterion - each species occupies a certain territory - an area. Many species occupy different ranges. But many species have coinciding (overlapping) or overlapping ranges, some have a broken range (for example, linden grows in Europe, it is found in the Kuznetsk Alatau and Krasnoyarsk Territory). In addition, there are species that do not have clear boundaries of distribution, as well as cosmopolitan species that live on vast expanses of land or ocean. Cosmopolitans are some inhabitants of inland water bodies - rivers and freshwater lakes (duckweed, reed). Cosmopolitans are among weeds, synanthropic animals (species that live next to a person or his home) - a bed bug, a red cockroach, a housefly, as well as a medicinal dandelion, a field yar, a shepherd's purse, etc. Thus, a geographical criterion, like others are not absolute.

Environmental criterion is based on the fact that each species can exist only under certain conditions: each species occupies a certain ecological niche. For example, caustic buttercup grows in floodplain meadows, creeping buttercup - along the banks of rivers and ditches, burning buttercup - in wetlands. However, there are species that do not have a strict ecological criterion; an example is synanthropic species.

Genetic criterion based on the difference in species by karyotype, i.e., by the number, shape and size of chromosomes. For the vast majority of species, a strictly defined karyotype is characteristic. However, this criterion is not universal. For example, in many different species, the number of chromosomes is the same and their shape is similar. Thus, many species from the legume family have 22 chromosomes (2n \u003d 22). Also, within the same species, individuals with a different number of chromosomes (the result of genomic mutations) can occur: goat willow has a diploid (38) and tetraploid (76) number of chromosomes; in the herring carp there are populations with a set of chromosomes 100, 150,200, while the normal number of them is 50. Thus, on the basis of a genetic criterion, it is not always possible to determine the belonging of individuals to a particular species.

Biochemical criterion Is the composition and structure of certain proteins, nucleic acids and other substances. For example, the synthesis of certain high-molecular substances is inherent only in certain species: alkaloids are formed by plant species of the families of Solanaceae and Liliaceae. But this criterion is not widely used - it is laborious and not always universal. There is a significant intraspecific variability of almost all biochemical parameters (the sequence of amino acids in the molecules of proteins and nucleotides in certain regions of DNA). At the same time, many biochemical signs are conservative: some are found in all representatives of this type or class.

Thus, none of the criteria alone can serve to determine the species: to determine the species, it is necessary to take into account the totality of all criteria. In addition to the listed features, scientists distinguish historical and ethological criteria.

Characteristics of type criteria

View criteria	Criterion characteristics
Morphological	The similarity of the external (morphological) and internal (anatomical) structure of individuals of the same species.
Physiological	The similarity of all life processes, and, above all, reproduction. Representatives of different species, as a rule, do not interbreed with each other, or produce infertile offspring.
Genetic	A characteristic set of chromosomes inherent only in this species, their structure, shape, size. Individuals of different species with an unequal set of chromosomes do not interbreed with each other.
Biochemical	Ability to form species-specific proteins; similarity of chemical composition and chemical processes.
Ecological	The adaptation of individuals of a given species to certain environmental conditions is a combination of environmental factors in which the species exists.
Geographical	A certain area, habitat and distribution in nature.
Historical	Origin and development of the species.
Ethological	Certain species characteristics in the behavior of individuals: differences in mating songs, in mating behavior.

View - a set of individuals characterized by a common origin, possessing hereditary similarities in morphological, physiological and biochemical characteristics, freely interbreeding with each other and giving fertile offspring, adapted to existing living conditions and occupying a certain territory - an area. All species are made up of populations, that is, a population is a structural unit of a species.

Populations – these are groups of organisms of the same species, relatively isolated from each other, with the ability to freely interbreed with each other and give fertile offspring.

View -a set of individuals with common morphophysiological characteristics and combined with the ability to interbreed with each other, forming a system of populations that form a common area.

The populations are characterized by certain properties:

1) number - the total number of organisms in the population;

2) fertility - the rate of population growth;

3) mortality - the rate of decline in numbers as a result of the death of individuals;

4) age composition - the ratio of the number of individuals of different ages (ratio of age groups);

5) sex ratio - based on the genetic determination of sex, the sex ratio in the population should be 1: 1, violation of this ratio leads to a decrease in the population size;

6) population dynamics - under the influence of various factors, periodic and non-periodic fluctuations in the number and size of the area are possible, which can affect the nature of crosses;

7) population density - the number of individuals per unit of space occupied by the population.

Populations do not exist in isolation: they interact with populations of other species, forming biotic communities.

Studying nature, scientists discovered and described previously unknown organisms, giving them names. At the same time, it often turned out that different scientists called the same organism differently. The more materials were accumulated, the more difficulties appeared in using the accumulated knowledge. It became necessary to bring all the variety of living organisms into a single system. The section of biology that deals with the description and classification of organisms is called taxonomy .

The first systems were artificial, as they were built on several randomly taken features. One of the classification systems for plants and animals was proposed by Karl Linnaeus (1707-1778). The merit of the scientist not only in the creation of a system by him, but also in the fact that he introduced double names of species: the first word is the name of the genus, the second is the species, for example, Aurelia aurita is the long-eared jellyfish, Aurelia cyanea is the polar jellyfish. This naming system still exists today. Subsequently, the system of the organic world, proposed by K. Linnaeus, was significantly changed. At the heart of the modern classification, which is natural,the principle of the relationship of species with both living and extinct ones lies.

Thus, the goal of the natural classification - creation of a unified system of living organisms, which would cover all the diversity of living organisms, reflect the origin and history of their development. In the modern system, organisms are divided into groups based on the links between them in origin. Systematic categories, or taxa, are the names of groups of living organisms that are united by similar characteristics. For example, the class Birds is a highly organized vertebrate animal whose body is covered with feathers, and the forelimbs are turned into wings. The largest systematic categories of organisms are empires (precellular and cellular organisms). Empires are divided into kingdoms.

Organic world

Kingdom Viruses

The Super Kingdom of the Prokaryote The Super Kingdom of the Eukaryote

(non-nuclear) (nuclear)

Kingdom of Bacteria

Kingdom of Plants Kingdom of Animals Kingdom of Mushrooms Kingdoms of animals unite types, and in plants - departments... Examples of systematic categories:

Systems in which the higher categories consistently include lower and lower categories are called hierarchical (from the Greek hieros - sacred, arche - power), that is, systems whose levels are subject to certain rules.

An important stage in the development of biology was the period of the formation of systematization, which is associated with the name Karl Linnaeus (1707-1778). K. Linnaeus believed that living nature was created by the Creator, the species are unchanged. The scientist based the classification on the signs of similarity, and not on the relationship between species. Despite the mistakes made by K. Linnaeus, his contribution to the development of science is enormous: he streamlined ideas about the diversity of flora and fauna.

At the end of the 18th century, there are changes in views on the origin of life: ideas appear about the origin of modern organisms from distant ancestors.

The idea of \u200b\u200bthe evolution of the organic world is expressed by Jean Baptiste Lamarck (1744-1829). The main merits of Lamarck include the following:

Introduced the term "biology";

Improved the classification already existing at that time;

I tried to determine the reasons for the evolutionary process (according to Lamarck, the reason for evolution is the desire for self-improvement - exercise and not exercise of organs);

He believed that the process of historical change proceeds from simple to complex; species change under the influence of environmental conditions;

Expressed the idea of \u200b\u200bhuman origin from ape-like ancestors.

The erroneous provisions of Lamarck include:

The idea of \u200b\u200ban inner striving for self-improvement;

The assumption about the inheritance of changes that have arisen under the influence of the external environment.

The merit of Lamarck is the creation of the first evolutionary doctrine.

In the 19th century, science, industry, and agriculture developed intensively. The successes of science and human practice laid the foundation on which evolutionary theory developed.

View (lat. species) is a taxonomic, systematic unit, a group of individuals with common morphophysiological, biochemical and behavioral characteristics, capable of mutual crossing, giving fertile offspring in a series of generations, regularly distributed within a certain area and similarly changing under the influence of environmental factors. A species is a really existing genetically indivisible unit of the living world, the main structural unit in a system of organisms, a qualitative stage in the evolution of life.

For a long time, it was believed that any species is a closed genetic system, that is, there is no gene exchange between the gene pools of two species. This statement is true for most species, but there are exceptions to it. So, for example, lions and tigers can have a common offspring (ligers and tigers), females of which are fertile - they can give birth from both tigers and lions. In captivity, many other species interbreed, which in natural conditions do not interbreed due to geographical or reproductive isolation. Crossing (hybridization) between different species can also occur in natural conditions, especially with anthropogenic disturbances in the habitat that violate the ecological mechanisms of isolation. Plants especially often hybridize in nature. A noticeable percentage of higher plant species are of hybrid origin - they were formed during hybridization as a result of partial or complete fusion of parental species.

Main type criteria

1. Morphological criterion of the species. Based on the existence of morphological characters characteristic of one species, but absent in other species.

For example: in the common viper, the nostril is located in the center of the nasal shield, and in all other vipers (nosed, Asia Minor, steppe, Caucasian, gyurza) the nostril is displaced to the edge of the nasal shield.
At the same time, there are significant individual morphological differences within the species. For example, the common viper is represented by many color forms (black, gray, bluish, greenish, reddish and other shades). These characteristics cannot be used to differentiate types.

2. Geographic criterion. It is based on the fact that each species occupies a certain territory (or water area) - a geographical area. For example, in Europe, some species of anopheles mosquito (genus Anopheles) inhabit the Mediterranean, others - the mountains of Europe, Northern Europe, Southern Europe.

However, the geographical criterion is not always applicable. The ranges of different species can overlap, and then one species smoothly passes into another. In this case, a chain of vicarious species (supraspecies, or series) is formed, the boundaries between which can often be established only through special research (for example, herring gull, black gull, western, Californian).

3. Environmental criterion. Based on the fact that two species cannot occupy one ecological niche. Hence, each species is characterized by its own relationship with its habitat.

However, within the same species, different individuals can occupy different ecological niches. Groups of such individuals are called ecotypes. For example, one Scots pine ecotype inhabits bogs (bog pine), another - sand dunes, and the third - leveled areas of pine forest terraces.

A set of ecotypes that form a single genetic system (for example, capable of interbreeding with each other to form full-fledged offspring) is often called an ecovid.

4. Molecular genetic criterion. Based on the degree of similarity and difference in nucleotide sequences in nucleic acids. Typically, "non-coding" DNA sequences (molecular genetic markers) are used to assess the degree of similarity or difference. However, DNA polymorphisms exist within the same species, and different species may have similar sequences.

5. Physiological and biochemical criterion. Based on the fact that different species can differ in the amino acid composition of proteins. At the same time, protein polymorphism exists within a species (for example, intraspecific variability of many enzymes), and different species may have similar proteins.

6. Cytogenetic (karyotypic) criterion. Based on the fact that each species is characterized by a certain karyotype - the number and shape of metaphase chromosomes. For example, all durum wheat has a diploid set of 28 chromosomes, and all soft wheats have 42 chromosomes. However, different species can have very similar karyotypes: for example, in most species of the feline family, 2n \u003d 38. At the same time, chromosomal polymorphism can be observed within the same species. For example, in the moose of the Eurasian subspecies, 2n \u003d 68, and in the moose of the North American species, 2n \u003d 70 (in the karyotype of the North American moose there are 2 less metacentrics and 4 more acrocentrics). Some species have chromosomal races, for example, the black rat has 42 chromosomal (Asia, Mauritius), 40 chromosomal (Ceylon) and 38 chromosomal (Oceania).

7. Reproductive criterion. It is based on the fact that individuals of the same species can interbreed with each other to form fertile offspring, similar to their parents, and individuals of different species living together do not interbreed with each other, or their offspring are sterile.

However, it is known that in nature is often widespread interspecific hybridization: in many plants (for example, willows), a number of species of fish, amphibians, birds and mammals (for example, wolves and dogs). At the same time, within the same species, there may be groups reproductively isolated from each other.

8. Ethological criterion. Associated with interspecies differences in animal behavior. Song analysis is widely used in birds for species recognition. By the nature of the sounds emitted, different types of insects differ. Different types of North American fireflies differ in the frequency and color of their light flashes.

9. Historical (evolutionary) criterion. Based on the study of the history of a group of closely related species. This criterion is complex in nature, since it includes a comparative analysis of the modern ranges of species (geographical criterion), a comparative analysis of genomes (molecular genetic criterion), a comparative analysis of cytogenomes (cytogenetic criterion), and others.

None of the considered species criteria is the main or the most important. For a clear separation of species, it is necessary to carefully study them according to all criteria.

Due to the unequal environmental conditions, individuals of the same species within the range break up into smaller units - populations. In reality, the species exists precisely in the form of populations.

Species are monotypic - with poorly differentiated internal structure, they are characteristic of endemics. Polytypic species are distinguished by a complex intraspecific structure.

Within species, subspecies can be distinguished - geographically or ecologically separate parts of a species, individuals of which, under the influence of environmental factors in the process of evolution, acquired stable morphophysiological features that distinguish them from other parts of this species. In nature, individuals of different subspecies of the same species can freely interbreed and give fertile offspring.

Species name

The scientific name of a species is binomial, that is, it consists of two words: the name of the genus to which this species belongs, and the second word, called in botany by the specific epithet, and in zoology by the specific name. The first word is a singular noun; the second is either an adjective in the nominative case, consistent in gender (masculine, feminine, or neuter) with the generic name, or a noun in the genitive case. The first word is written with a capital letter, the second with a lowercase letter.

• Petasites fragrans - the scientific name of a species of flowering plants from the genus Butterbur ( Petasites) (the Russian name of the species is fragrant butterbur). The adjective is used as a specific epithet fragrans ("fragrant").
• Petasites fominii - the scientific name of another species from the same genus (Russian name - Fomina's Butterbur). The Latinized surname (in the genitive case) of the botanist Alexander Vasilyevich Fomin (1869-1935), a researcher of the flora of the Caucasus, was used as a specific epithet.

Records are sometimes also used to denote undefined taxa at the rank of the species:

• Petasites sp. - the record indicates that the taxon in the rank of the species, belonging to the genus, is meant Petasites.
• Petasites spp. - the entry means that all taxa in the rank of the species included in the genus are meant Petasites (or all other taxa in the rank of the species included in the genus Petasites, but not included in any given list of such taxa).



The set of properties and common features inherent in one species is called a species criterion. Usually, six to ten criteria for determining the species are used.

Systematization

A species is a systematic or taxonomic unit that has a common characteristic and unites on its basis a group of living organisms. To distinguish a biological group into one species, one should take into account a number of features associated not only with distinctive external features, but also with living conditions, behavior, distribution, etc.

The term "species" was used to group externally similar animals into groups. By the end of the 17th century, a lot of information about species diversity had accumulated, and the classification system required revision.

Karl Linnaeus in the 18th century combined species into genera, and genera into orders and classes. He proposed a binary designation nomenclature, which helped to greatly shorten the species names. According to Linnaeus, names began to be formed from two words - the names of the genus and species.

Figure: 1. Karl Linnaeus.

Linnaeus was able to systematize species diversity, but he himself mistakenly distributed animals by species, relying mainly on external data. For example, he attributed the male and female duck to different species. Nevertheless, Linnaeus made a huge contribution to the study of species diversity:

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Later, the biological concept of the species appeared, confirming that the classification by species is natural, genetically determined, and not artificial, created by people for the convenience of systematization. In fact, a species is an indivisible unit of the biosphere.

Despite the possibilities of modern science, many species have not yet been described. As of 2011, about 1.7 million species have been described. At the same time, there are 8.7 million species of plants and animals in the world.

Criteria

According to the criteria, you can determine whether individuals belong to the same or different species. First of all, the morphological criterion of the species is distinguished, i.e. representatives of different species should differ in external and internal structure.

However, this criterion is often not enough to distinguish a group of living organisms into a separate species. Individuals can differ in behavior, lifestyle, genetics, so it is important to take into account a set of criteria and not draw conclusions based on one trait.

Figure: 2. Morphological similarity of barbel species.

The table “Species Criteria” describes the most important criteria by the combination of which a species can be recognized.

Name	Description	Examples of
Morphological	The similarity of the external and internal structure and the difference from other types. Not to be confused with sexual dimorphism	Titmouse blue tit and muscovy
Physiological	The similarity of life processes in cells and organs, the ability for one type of reproduction	The difference in the composition of insulin in a bull, horse, pig
Biochemical	Composition of proteins, nucleotides, biochemical reactions, etc.	Plants synthesized by various substances - alkaloids, essential oils, flavonoids
Ecological	Single ecological niche for one species	Bovine tapeworm intermediate host - cattle only
Ethological	Behavior, especially during mating season	Attracting a partner of your own species with special singing in birds
Geographical	Settling in one area	The habitats of humpback whales and dolphins do not match
Genetic	A certain karyotype - the similarity of the number, shape, size of chromosomes	The human genotype consists of 46 chromosomes
Reproductive	Individuals of the same species can only interbreed with each other, reproductive isolation	The sperm of a Drosophila fly, falling into a female of a different species, is destroyed by immune cells
Historical	A set of genetic, geographic, evolutionary data about one species	The presence of a common ancestor and differences in evolution

None of the criteria are absolute and have exceptions to the rule:

• externally dissimilar species have the same set of chromosomes (cabbage and radish - 18 each), while within the species mutations can be observed and populations with an excellent set of chromosomes can be found;
• black rats (sibling species) are morphologically identical, but genetically not, and, therefore, cannot produce offspring;
• in some cases, individuals of different species are crossed (lions and tigers);
• habitats often overlap or are ruptured (Western European and East Siberian magpie ranges).

Hybridization is one of the levers of evolution. However, for successful crossing and obtaining fertile offspring, many criteria must coincide - genetics, biochemistry, physiology. Otherwise, the offspring will be unviable.

Figure: 3. Liger is a hybrid of a lion and a tigress.

What have we learned?

From the 11th grade biology lesson, they learned about the concept of a species and the criteria for its definition, considered nine main criteria with the given examples. The criteria should be considered together. Only if several criteria are met can similar organisms be combined into a species.

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Biology. General biology. Grade 11. Basic level Sivoglazov Vladislav Ivanovich

5. Type: criteria and structure

5. Type: criteria and structure

Remember!

What levels of wildlife organization do you know?

What is a View?

What other taxonomic categories are you aware of?

The evolutionary theory of Charles Darwin is based on the concept of a species. What is a species and how real is its existence in nature?

The first idea of \u200b\u200ba species was created by Aristotle, who defined a species as a collection of similar individuals. The term "species" itself, translated from Latin, means "image". This word precisely defines the main criterion that researchers used until the 19th century. when determining the species of any organism. The famous scientist K. Linnaeus, who created the doctrine of the species, believed that the species consists of many similar individuals giving fertile offspring.

In modern biology kind called a set of individuals possessing similar morphological and physiological characteristics, capable of interbreeding with the formation of fertile offspring, inhabiting a certain area (habitat), having a common origin and similar behavior.

A species is not only the main taxonomic unit in biological systematics. It is a holistic structure of living nature, which is reproductively isolated from other similar structures and has its own destiny. The integrity of this system is given, firstly, by the processes of interaction between individuals. The relationship between organisms of different generations, between parents and children, males and females, features of territorial behavior - all this determines the internal structure of the species. Species traits do not always ensure the survival of an individual, but they are always favorable for the species as a whole. For example, a bee that has lost its sting will die, but it will protect the rest of the individuals.

The second reason for maintaining the unity and integrity of a species is reproductive isolation, that is, the impossibility of crossing with individuals of another species. This is how protection is carried out gene pool of the species (the entire set of genes of a species) from the influx of alien genetic information. There are various factors that prevent interspecies crossing. For example, two closely related pine species grow in California. In one of them, the pollen spills out in early February, and in the other in April, so there is seasonal isolation between these species. In higher animals, mating behavior has characteristic specific features, therefore, females of one species do not respond to the courtship of males of another closely related species - this is an example of behavioral isolation (Fig. 12).

The presence of reproductive isolation in natural conditions is a decisive factor in defining a species as a genetically closed biological system.

The characteristics and properties that distinguish some species from others are called species criteria.

View criteria. There are several main criteria for a species.

Morphological criterion lies in the similarity of the external and internal structure of organisms. For a long time, this criterion was the main, and sometimes the only one. With its help, individuals of distant species are easily identified. Even a small child can distinguish between a cat and a mouse, a mouse and a rat - any adult, but only a specialist can distinguish between a house mouse and a small mouse. There are special qualifiers that are based on the morphological features of the organization. However, within a species, there is always structural variation between different individuals, so it is sometimes difficult to determine the species of a particular individual.

Genetic criterion. Sometimes, among very similar individuals, groups are found that do not interbreed with each other. These are the so-called sibling species, which are found in almost all large systematic groups and differ from each other in the number of chromosomes. For example, among insects, there are two widespread wasp species, which until recently were considered as a single species (Fig. 13).

Figure: 12. Different types of mating behavior of two closely related species of gulls

Figure: 13. Twin species. Wasp insects (A, B) with different karyotypes (C): 2n \u003d 10 and 2n \u003d 14

Each species has a certain set of chromosomes - a karyotype, which differs in the number of chromosomes, their shape, size, and structure. The different number of chromosomes in the karyotype of different species and the species differences of genomes provide genetic isolation during interspecies crossing, because they cause the death of gametes, zygotes, embryos, or lead to the birth of infertile offspring (hinny is a hybrid of a horse and a donkey). It is the use of the genetic criterion that allows one to reliably distinguish between sibling species.

Physiological criterion reflects the similarity of all vital processes in individuals of the same species: the same methods of feeding, reproduction, similar reactions to external stimuli, the same biological rhythms (periods of hibernation or migration). For example, in two closely related species of the fruit fly, Drosophila, sexual activity is observed at different times of the day: in one species, in the morning, in the other, in the evening.

Biochemical criterion is determined by the similarity or difference in the structure of proteins, the chemical composition of cells and tissues. For example, certain types of lower fungi differ from each other in their ability to synthesize various biologically active substances.

Environmental criterion characterized by certain forms of relationships between organisms of a given species with representatives of other species and factors of inanimate nature, that is, the conditions in which this species occurs in nature. In Texas, closely related oak species grow on different soils: one species is found only on limestone soil, another on sandy soil, and the third grows on outcrops of igneous rocks.

Geographic criterion defines the area of \u200b\u200bdistribution, i.e. area, species. The size of the ranges is very different for different species. Species that occupy vast areas and are found everywhere are called cosmopolitans, and living in small areas and not found elsewhere, - endemics.

Thus, to determine the species of an organism, it is necessary to use all the criteria in aggregate, because individual criteria in different species may coincide.

View structure... In reality, in nature, individuals of any species within the range are unevenly distributed: somewhere they form clusters, and somewhere they may be absent altogether. Such partially or completely isolated groupings of individuals of one species are called populations (from the Latin populus - people, population), that is, in natural conditions, any species consists of a set of populations.

Population - this is a collection of individuals of one species, for a fairly long time (a large number of generations) inhabiting a certain territory within the range of the species, freely interbreeding with each other and partially or completely isolated from individuals of other similar assemblies.

It is the population that is elementary unit of evolution.

Review questions and assignments

1. Give a definition of the concept "species".

2. Tell us what biological mechanisms prevent the exchange of genes between species.

3. What is the reason for the infertility of interspecific hybrids? Explain this phenomenon using your knowledge of the mechanism of meiosis.

4. What criteria do scientists use to characterize a species? What criteria do you consider the most important in determining the species?

5. What is the range of the species?

6. Describe the type of domestic cat according to the main criteria.

7. Give a definition of "population".

Think! Execute!

1. Why one species from another can be distinguished only by a combination of various criteria? What criteria do you think are the most important?

2. Do you know of examples when the formulation “a species as a genetically closed system” turned out to be incorrect? (Think of the material on selection from the 10th grade course.)

3. Do your research. Find out which species in your area are endemic and which are cosmopolitan. Prepare a progress report in the form of a stand.

4. In your opinion, can the words "population" and "popular" be considered the same root? Explain your point of view.

5. Provide evidence to show that species objectively exist in nature.

Work with computer

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

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4.1. Differential Diagnostic Criteria Simple observation of the animal and conversation with the owners is not enough to make a definitive diagnosis. Thus, we are faced with the task of differential diagnosis. With certain restrictions and amendments to

From the book Ecology by Mitchell Paul

COMMUNITY: STRUCTURE What processes determine the abundance and diversity of species in a particular community? What processes determine the structure of a community? To what extent the structure of a community is determined by local processes taking place within the community

From the book Biology [Complete guide to prepare for the exam] author Lerner Georgy Isaakovich

From the book Stop, Who Leads? [The biology of human and other animal behavior] author Zhukov. Dmitry Anatolyevich

From the book We are immortal! Scientific evidence for the Soul author Mukhin Yuri Ignatievich

Sleep structure Night sleep consists of several cycles, each of which lasts about an hour and a half and includes two qualitatively different stages, called "slow sleep" and "REM sleep". Stages of REM and slow sleep are not only in humans, but also

From the book Human Genetics with the Basics of General Genetics [Study Guide] author Kurchanov Nikolay Anatolievich

Truth criteria Having evaluated all the possible and available initial data for further reflections, we finally come to the question of "how it works" - how life is created and functions. And, accordingly, they came to the need to put forward theories that

From the book Secrets of Sex [Man and Woman in the Mirror of Evolution] author Butovskaya Marina Lvovna

3.3. Chromosome structure Each chromatid contains one DNA molecule associated with histone and non-histone proteins. At present, a nucleosome model of the organization of eukaryotic chromatin has been adopted (Kornberg R., 1974; Olins A., Olins D., 1974). According to this model, histone proteins (they

From the book Biological Chemistry author Lelevich Vladimir Valerianovich

Chapter 4. Criteria for sex in humans The tradition of male dominance over women outside the home (first of all, it is about social life and politics) laid down by ancient Greek culture has significantly influenced the development of scientific ideas about

From the author's book

Chapter 9. The Knight and the Fair Lady: Criteria for Male and Female Attractiveness Outward Attractiveness: The Multiple Fitness Model Empirical evidence suggests that natural selection can influence social perception

MORPHOLOGICAL APPEARANCE

FOR MORPHOLOGICAL APPEARANCE see. Fenon.

Ecological encyclopedic dictionary. - Chisinau: Main editorial office of the Moldavian Soviet Encyclopedia... I.I. Grandfather. 1989.

• MORFOKLIMAX
• MORPHOLOGY

See what "MORPHOLOGICAL SPECIES" is in other dictionaries:

Morphological analysis is an example of a systematic approach in the field of invention. The method was developed by the famous Swiss astronomer F. Zwicky. Thanks to this method, he managed to obtain in a short time a significant number of original ... ... Wikipedia

VIEW - biological, the basic structural unit in the system of living organisms; a group of actually or potentially interbreeding populations, reproductively isolated from other similar populations of species and having a common protected gene pool. IN… … Ecological Dictionary

View - * species * species is the basic taxonomic or systematic unit of living organisms that actually exists in nature and occupies a certain area. It is a set of populations (see) composed of individuals that are related by ... ... Genetics. encyclopedic Dictionary

The main taxonomic unit, a set of individuals of the same genotype, with a well-expressed phenotypic similarity. A strict, generally accepted definition of V. has not yet been developed. (Source: "Microbiology: Dictionary of Terms", Firsov N.N. ... Microbiology Dictionary

A Zwicky cube allows you to represent various combinations of possible realizations of object parameters, such as color, shape, and texture. This term has other meanings, see Morphological analysis. Morphological analysis ... Wikipedia

The title page of Carl Linnaeus's Species Plantarum. May 1, 1753 the date of publication of the book is taken as the starting point of the botanical nomenclature. A species (Latin species) is a taxonomic, systematic unit, a group of individuals with ... ... Wikipedia

- (analysis by parts of speech). If the object of analysis is a sentence, then its morphological composition is found out, followed by a description of individual words related to one or another part of speech. First, the constant morphological ... ... Dictionary of linguistic terms

- ... Wikipedia

appearance - ▲ characteristic of an object, from the point of view, space appearance is a spatial characteristic. externally. external view. habit. appearance. outer. outwardly. outside. view. visible. by sight (# the kid is about five years old). at first sight. by… … Ideographic Dictionary of the Russian Language

Polycythemia ICD 10 D45. (ICD O 9950/3), D75.1, P61.1 ICD 9 ... Wikipedia

Books

• A set of tables. Russian language. Morphology. 15 tables,. Educational album of 15 sheets. Art. 5-8681-015. Morphological parsing of a word as part of speech. Allocation of morphological features of nouns and adjectives by comparison. ...
• Morphological analysis. Grades 2-4, Olga Dmitrievna Ushakova. Morphological parsing of words is a very important type of work in Russian lessons. We hope that with the help of our practical exercise book, children, as they say, will fill their hands in this type of analysis and ...