home Calculators Directional factors. Guiding factors of evolution. Key features and cascading interactions

Directional factors. Guiding factors of evolution. Key features and cascading interactions

Question 1. Name the main factors of evolution.
According to the synthetic theory of evolution, the elementary evolutionary phenomenon from which speciation begins is a change in the genetic composition (genetic constitution, or gene pool) of a population. Events and processes that help overcome the genetic inertia of populations and lead to changes in their gene pools are called elementary euloluconic factors. The main factors (forces) of evolution are:
1) Factors causing changes in the gene pool of the population. These include hereditary variability, which supplies new genetic material to the population, and population waves, isolation, which form differences between the gene pools of different populations
2) A factor that allows a population to develop independently relative to other populations or divides the original population into two or more new ones. This factor is isolation.
3) A factor that directs the evolutionary process and ensures that certain adaptations and changes in organisms are consolidated in the population. Natural selection serves as such a factor.

Question 2. What factor ensures the emergence of new genetic material in a population?
The factor that ensures the emergence of fundamentally new genetic material is mutational variability.
Under favorable conditions of existence, small differences between individuals of the same species are not very noticeable and do not play a significant role. However, under unfavorable conditions, even small hereditary changes can be decisive and determine which individuals of the population will die and which will survive. Hereditary variability provides material for the evolutionary process.
Mutations occur with a certain frequency in all organisms inhabiting our planet. The location of the mutation (gene and chromosome) is random, so mutations can affect any characteristics and properties of an individual, including those affecting viability, reproduction, and behavior. Over the course of generations, the vast majority of mutations are preserved, starting with those that arose in the most ancient ancestors. As a result, the set of mutations in two populations of the same species turns out to be very similar. On the other hand, various mutations will also be present. Their number is an indicator of how long ago the two populations became isolated from each other.
Thus, the mutation process is a source of reserve of hereditary variability of populations. By maintaining a high degree of genetic diversity in populations, it provides the basis for natural selection to operate.

Question 3. Will selection act on carriers of recessive mutations?
As a rule, carriers of recessive mutations (heterozygous organisms) do not differ noticeably in properties from homozygous dominant organisms. Moreover, in the heterozygous state, many mutations increase the viability of individuals. Therefore, selection usually does not act on such individuals. After a certain time, a sufficiently large number of recessive alleles can accumulate in a population, i.e. the proportion of heterozygous organisms will increase. This will lead to an increase in the likelihood of their meeting and, as a consequence, to the birth (in 25% of cases) of recessive homozygotes. It should also be borne in mind that in nature mutations occur in combination with each other. Some combinations due to the interaction of genes can be positive for an individual, increasing its viability. This is where natural selection can begin to act.

Question 4. Give an example illustrating the change in the significance of a mutation when environmental conditions change.
Mutations that are harmful in some conditions can increase the viability of an individual in other environmental conditions. Mutations that are harmful in some conditions can increase viability. individuals in other environmental conditions. For example, mutant insects that are wingless or have poorly developed wings have an advantage on oceanic islands and mountain passes where strong winds blow. For similar reasons, the formation of species now exterminated by humans, such as the dodo and the great auk, occurred.
An example is a mutation in insects that provides resistance to a pesticide. Over time, this mutation will be neutral, and its occurrence in the population will be low. But after this pesticide begins to be used to control insects, the mutation will become useful, since it will ensure the survival of individuals in changed conditions. Thanks to the action of selection, the proportion of this mutation in the gene pool of the population will increase sharply - the faster, the stricter the selection, i.e., the greater the percentage of individuals die in each generation from the action of the pesticide. It is clear that such events will manifest themselves much more clearly if the mutation of resistance to the pesticide is dominant.

Question 5. Is the mutation process capable of exerting a directing influence on the process of evolution and why?
The mutation process is a random, nonspecific phenomenon. Mutations arise undirectedly and have no adaptive significance, that is, they cause uncertain hereditary variability (according to Charles Darwin). With equal probability, mutations can lead to changes in any organ system. Thus, the mutation process in itself is not capable of exerting a directing effect on the course of evolution.

Question 6. What is genetic drift?
Genetic drift is a process of random, non-directional change in allele frequencies in a population. It is observed when a population passes through a state of low numbers (the so-called “bottleneck” effect, which occurs as a result of epidemics and natural disasters). As a result of random genetic drift, genetically homogeneous populations living in similar conditions can gradually lose their original similarity. Genetic drift is one of the factors contributing to population change.

Question 7. What factor leads to the cessation of the exchange of genetic information between populations? What is its evolutionary significance?
The cessation of the exchange of genetic information is facilitated by isolation - the restriction or cessation of crossings of individuals belonging to different populations. Isolation can be spatial or environmental.
Geographic isolation consists of spatial separation of populations due to landscape features within the species’ range - the presence of water barriers for “land” organisms, land areas for aquatic species, alternation of elevated areas and plains. It is promoted by a sedentary or immobile (in plants) lifestyle.
Ecological isolation occurs if individuals are separated by environmental barriers within the same landscape, for example, the probability of encountering inhabitants of shallow and deep parts of a reservoir during the breeding season is very low. Long-term ecological isolation contributes to the divergence of populations up to the formation of new species. Thus, it is assumed that the human and pork roundworms, which are morphologically similar, originated from a common ancestor. Their divergence, according to one hypothesis, was facilitated by the ban on human consumption of pork meat, which for religious reasons extended for a long time to significant masses of people. Ecological isolation exists due to the nuances of the courtship ritual, coloring, smells, and “singing” of females and males from different populations. Thus, the subspecies of goldfinches - gray-headed and black-headed - have pronounced markings on their heads. Hooded crows from the Crimean and Northern Ukrainian populations, outwardly indistinguishable, are distinguished by their croaking. With physiological isolation, differences in the structure of the reproductive organs or simply differences in body size serve as an obstacle to crossing. In plants, this form of isolation is caused by the adaptation of the flower to a particular type of pollinator.
Isolation in the process of speciation interacts with other elementary evolutionary factors. It enhances the genotypic differences created by the mutation process and genetic combinatorics. Intraspecific groups that arise due to isolation differ in genetic composition and experience unequal selection pressure. The evolutionary significance of isolation lies in the fact that it consolidates and enhances genetic differences between populations and creates the preconditions for the further transformation of these populations into separate species.

From the point of view of supporters of “opportunistic evolution”, behind the various directions of evolutionary changes there are no natural and organizing tendencies, except for the action of natural selection, which organizes the variability of organisms only in the direction of developing adaptations to changes in the environment. From these positions, the main directions of the evolutionary process (aro-, epecto-, allo- and catagenesis) are essentially equivalent - in the sense that each of them is only a means for achieving success for a given group of organisms in the struggle for existence (at such a point A. N. Severtsov also shared this view).

Indeed, among the driving factors of evolution, only natural selection has an organizing effect on the variability of organisms, and at the same time, selection is truly devoid of a specific direction, which was emphasized by Charles Darwin. But Darwin also pointed to a factor that determines specific directions of evolutionary transformations: “The nature of conditions has a subordinate importance in determining each given change compared to the nature of the organism itself” 1 . Although the evolution of organisms is based on probabilistic processes - the occurrence of mutations (the phenotypic manifestation of which is inadequate to the changes in external conditions that caused their appearance) and natural selection, the “nature of the organism,” i.e., the organizational basis of living systems, limits the manifestations of randomness in evolution to a certain framework. In other words, the systemic organization channels phylogeny, that is, it directs evolutionary transformations in certain directions, and for any specific group of organisms the choice of possible evolutionary paths is limited. The concept of hard-coded (nomogenetic) evolution is based on the absolutization of the guiding role in the evolutionary process of the organizational basis of living systems, while the concept of opportunistic evolution is based on the absolutization of the guiding role of natural selection. Typically, truth is to be found somewhere between extreme points of view.

Specific directions of phylogenetic transformations of various groups of organisms are determined by the interaction of the forces of natural selection and historically established organization

"Darwin Ch. Origin of Species. - M., 1987. - P. 24.

these groups. Therefore, we can talk about two categories guiding factors of evolution: extra-organismal (forces of selection) and organic.

For any given species, the features of its organization create prerequisites (pre-adaptation) for the development of certain adaptations and prevent the development of others, “allow” some directions of evolutionary transformations and “prohibit” other directions. The totality of these positive and negative characteristics of the evolutionary capabilities of a given group is designated as organismal guiding factors of evolution. These factors can be divided (somewhat arbitrarily) into three categories, according to the level of their manifestation in ontogenesis: 1) genetic, 2) morphogenetic, 3) morphophysiological (morphofunctional).

The action of the first two categories of organismal guiding factors is fully manifested already at the level of microevolution. As already noted (Part II, Chapter 1), each genotype and gene pool of each species is characterized by a certain set of possible (“allowed”) mutations, or a spectrum of mutational variability, which is limited not only qualitatively, but also quantitatively, i.e., by a certain the frequency of occurrence of each type of mutation. At the same time, some mutations turn out to be impossible (forbidden) for a given genotype (and gene pool) - for example, blue and green eye colors for Drosophila flies or blue flower colors for Rosaceae. The reason for this is the lack of appropriate biochemical prerequisites in the genotype.

Since the gene pools of related species retain sets of homologous genes inherited from a common ancestor, homologous mutations naturally appear in them (see p. 71). Homologous mutations can serve as the basis for parallel evolutionary changes in closely related species that have diverged relatively recently from a common ancestor. However, over time, mutations of different quality (non-homologous) inevitably accumulate in the gene pools of isolated species; this occurs even under the influence of stabilizing selection, when the phenotypic effect of mutations in structural genes is blocked by modifier genes. Different species whose gene pools have been isolated from each other for quite a long time retain homologous phenotype structures, but their genetic control can vary significantly (and even almost completely). Therefore, the parallel evolution of phyletic lineages that have long diverged from a common ancestor (to the level of different genera, families, etc.) is based not so much on homologous mutations, but on the action of two other categories of organismal directing factors.

Some mutations that are biochemically possible for a given genotype (i.e., permitted at the genetic level), ultimately, however, lead to disastrous consequences for the developing organism in the form of disturbances in morphogenesis (lethal mutations, for example, the morphogenetic consequences of a mutation in congenital hydrocephalus in house mouse, see p. 331). Each ontogeny can be changed only in a certain way, that is, within the corresponding spectrum of possible ontogenetic changes. This further narrows the choice of possible directions for evolutionary transformations.

Finally, there are also morphophysiological evolutionary restrictions and prohibitions, the effect of which (as well as the corresponding preadaptations) is fully manifested only on the scale of macroevolution, being one of the specific reasons for its directed nature. They are caused by various relationships within morphophysiological systems and between these systems in the phenotype of adult organisms. At the same time, mutations and ontogenetic rearrangements, which could lead to corresponding changes in the phenotype, are themselves quite possible, and mutant individuals can appear with a certain frequency in populations of a given species. However, the resulting changes in phenotype (even those seemingly of high adaptive value!) cannot be used to form new adaptations due to their inconsistency with the morphophysiological organization of a given species. Such transformations remain impracticable until the corresponding morphophysiological prohibitions are lifted.

For example, keratinization can develop in the epidermis of amphibians - there are the necessary biochemical prerequisites for this, and there are no morphogenetic prohibitions for this process. Indeed, local keratinizations of the epidermis develop in the integument of some species of amphibians (for example, horny claws in clawed frogs or in male clawed newts, horny “teeth” in tadpoles of many species of tailless amphibians). However, it turned out to be impossible for amphibians to form on this basis such keratinization of the integument that could effectively protect the body from dehydration in the air and in salty bodies of water, as in reptiles, birds and mammals. This is due to the need for amphibians to maintain a constantly moist skin surface, which is used as an additional organ of gas exchange, primarily for removing carbon dioxide from the body (see below for more details).

Morphophysiological evolutionary restrictions and prohibitions are caused by the need for harmonious rearrangements of body systems that are integrated adaptively (i.e., included in the general adaptive complex), functionally, or at least topographically. In phylogeny, the effect of such restrictions manifests itself in the form of various coordination(i.e. phylogenetic correlations) 1 between different structures and systems of the body. Under topographic coordination the most simple conjugate evolutionary changes of organs that are closely related spatially are understood. For example, an increase in the size of the eyes is impossible without corresponding restructuring of the skull, changes in the position of muscles, blood vessels and nerves in the orbit and temporal region. Dynamic coordination represent phylogenetic relationships of organs connected with each other in ontogenesis by functional correlations. An example of evolutionary constraints based on such coordinations is the impossibility of strengthening any muscle group without corresponding strengthening of the skeletal structures and some other muscle groups, since this would make the coordinated work of the musculoskeletal system mechanically imperfect. Thus, there is no point in developing powerful thigh muscles while preserving the weaker lower leg muscles, since the latter cannot effectively transfer the contraction force of the former to the substrate. At the same time, the muscles of the lower leg cannot be significantly strengthened in animals adapted to fast running, since this would significantly increase the moment of inertia of the limb. This evolutionary limitation requires the development of a characteristic design of the limbs in fast running animals, in which the bulk of the muscles are located in the proximal sections (shoulder, thigh), and the force of their contraction is transmitted to the support through thin and light distal sections (forearm, lower leg, foot) through the system tendons

I. I. Shmalhausen also identified the so-called biological coordination, which are understood as associated changes in organs and individual structures that are not directly related to each other by any correlations in ontogenesis, but are included in the general adaptive complex (for example, evolutionary relationships between the structure of masticatory muscles, teeth, jaw bones and jaw joints, determined in a certain way nutrition). Coordinated evolutionary changes in these heterogeneous structures are determined by natural selection.

Homology is the similarity of structures based on their common origin. The relationship between homologous structures belonging to different levels of the hierarchical organization of biological systems (including genetic and phenotypic homology) is complex and ambiguous.
The term “coordination” to denote the phylogenetic relationships of organs was introduced by A.N. Severtsov.
See the book: Alexander R. Biomechanics. - M., 1970.

Charles Darwin (1809-1882)Shrewsbury House
(England), where Ch. was born.
Darwin
Charles Darwin's father
Robert Waring Darwin
Ch. Darwin's mother
Susanna Darwin

Charles Darwin was born on February 12, 1809.
in the family of a doctor. While studying at
universities of Edinburgh and Cambridge
Darwin gained in-depth knowledge of the field
zoology, botany and geology, skills and
taste for field research. Large
role in the formation of his scientific
worldview played by the book of outstanding
English geologist Charles Lyell
"Principles of Geology".

The decisive turn in his fate was
circumnavigation of the world on the Beagle
(1832-1837). According to Darwin himself,
during this journey he was influenced
most powerful impression: “1) discovery
giant fossil animals that
were covered with a shell similar to the shell
modern armadillos; 2) then
the fact that as we move along
closely related to the mainland of South America
animal species replace one another; 3) that
fact that closely related species of different
islands of the Gallapagos archipelago
differ slightly from each other. Was
It is obvious that this kind of facts, as well as
many others could only be explained
based on the assumption that species
gradually changed, and this problem became
Chase me".

Voyage around the world on the ship "Beagle" 1831-1836

Darwin returns from around the world
travel staunch supporter
views on the variability of species

Prerequisites for the emergence of Charles Darwin's theory

1. Discoveries in biology
cellular structure of organisms - R. Hooke,
A. Levenguk
similarity of animal embryos - K. Baer
discoveries in comparative anatomy
and paleontology – J. Cuvier
2. Works of geologist Charles Lyell on evolution
Earth's surface under the influence
natural causes (t, wind, precipitation, etc.)
3. Development of capitalism, agriculture,
selection
4. Creation of animal breeds and plant varieties
5. 1831-1836 - trip around the world on
Beagle

The importance of artificial selection for the creation of Darwin's theory

Artificial selection is the process of creating new
breeds (varieties) through systematic selection and
reproduction of individuals with valuable to humans
signs
From the analysis of huge material on the creation
breeds and varieties Darwin derived the principle
artificial selection and its basis
created his own evolutionary doctrine

individuals selected by humans for reproduction
pass on their characteristics to their descendants (heredity)
the diversity of descendants is explained by different
combinations of traits from parents and mutations
(hereditary (uncertain according to Darwin)
variability)

The creative role of artificial selection

Artificial selection leads to change
an organ or feature of interest to a person
Artificial selection leads to divergence
characteristics: members of the breed (variety) are increasingly and
become more unlike the wild species
Artificial selection and heredity
variability is the main driving force in
formation of breeds and varieties

Forms of artificial selection

Unconscious selection is selection in which
The goal is not to create a new variety or breed.
People keep the best, in their opinion, individuals and
destroy (cull) the worst (more productive)
cows, best horses)
Methodical selection is selection
carried out by a person according to a specific plan,
for a specific purpose - creating a breed or variety

Creation of evolutionary theory

1842 – work on the book began
"Origin of Species"
1858 – A. Wallace, while in
traveling in Malay
archipelago, wrote an article “About
the desire of varieties to
unlimited deviation from
original type" in which
contained theoretical
provisions similar to
Darwinian.
1858 - Ch. Darwin received from A.R.
Charles Darwin
(1809-1882, England)
Alfred Wallace
(1823-1913, England)

Creation of evolutionary theory

1858 – July 1 at a special Meeting
Linnean Society were outlined
concepts of C. Darwin and A. Wallace about
the emergence of species through natural
selection
1859 – first edition of the book “Origin
species", 1250 copies

All creatures have a certain
level of individual variability
Traits are passed on from parents
descendants by inheritance
Every type of organism is capable of
unlimited reproduction (in
poppy box 3000 seeds, elephant for
all life brings up to 6 baby elephants, but
offspring of 1 pair in 750 years = 19 million.
individuals)
Lack of vital resources
leads to a struggle for existence
Survive in the struggle for existence
best adapted to data
conditions of the individual

Darwin's concept of natural selection

Material for evolution - uncertain variability
Natural selection is a consequence of the struggle for
existence
Forms of struggle for
existence
Intraspecific
(between
individuals
one type)
Interspecific
(between
individuals
different types)
Fight with
unfavorable
conditions (t,
lack of water and
food, etc.)

Driving forces of evolution according to Darwin

Hereditary variability
Struggle for existence
Natural selection

Natural selection is the main guiding factor of evolution

The result of natural selection
Adaptation,
providing
y survival
And
reproduced
no offspring
Divergence –
gradual
discrepancy
groups of individuals according to
separate
signs and
education
new species

So, the idea of the origin of species through natural selection arose from
Darwin in 1838. He worked on it for 20 years. In 1856, on the advice of Lyell
he began preparing his work for publication. In 1858, young English
scientist Alfred Wallace sent Darwin the manuscript of his article “On the Tendency
varieties to unlimited deviation from the original type." This
the article contained a presentation of the idea of the origin of species through natural
selection His idea of evolution met with passionate support from some scientists and
harsh criticism of others. This and Darwin's subsequent writings, Changes
animals and plants during domestication", "The origin of man and sexual
selection", "Expression of emotions in humans and animals" immediately after release
translated into many languages. It is noteworthy that the Russian translation of the book
Darwin's "Changes in Animals and Plants under Domestication" was
published earlier than its original text.

Charles Darwin (1809-1882)Shrewsbury House
(England), where Ch. was born.
Darwin
Charles Darwin's father
Robert Waring Darwin
Ch. Darwin's mother
Susanna Darwin

Voyage around the world on the ship "Beagle" 1831-1836

Darwin returns from around the world
travel staunch supporter
views on the variability of species

Prerequisites for the emergence of Charles Darwin's theory

The importance of artificial selection for the creation of Darwin's theory

The creative role of artificial selection

10. Forms of artificial selection

11. Creation of evolutionary theory

12. Creation of evolutionary theory

13. Darwin's concept of natural selection

14. Darwin's concept of natural selection

15. Driving forces of evolution according to Darwin

Hereditary variability
Struggle for existence
Natural selection

16. Natural selection is the main guiding factor of evolution

17.

Hereditary variability

Random (non-directional) storage of features

Population waves- periodic fluctuations in population size. For example: the number of hares is not constant, every 4 years there are a lot of them, then a decline in number follows. Meaning: During decline, genetic drift occurs.

Genetic drift: if the population is very small (due to disaster, disease, decline of the pop wave), then traits persist or disappear regardless of their usefulness, by chance.

Struggle for existence

Cause: Many more organisms are born than can survive, so there is not enough food and territory for them all.

Definition: the totality of relationships of an organism with other organisms and with the environment.

Shapes:

intraspecific (between individuals of the same species),
interspecific (between individuals of different species),
with environmental conditions.

The intraspecific one is considered the most fierce.

Consequence: natural selection

Natural selection

This is the main, leading, directing factor of evolution, leading to adaptability, to the emergence of new species.

Insulation

Gradual accumulation of differences between populations isolated from each other can lead to the fact that they will not be able to interbreed - there will be biological containment, two different views will appear.

Types of isolation/speciation:

Geographical - if there is an insurmountable barrier between populations - a mountain, river or a very large distance (occurs with rapid expansion of the range). For example, Siberian larch (in Siberia) and Daurian larch (in the Far East).
Ecological - if two populations live in the same territory (within the same area), but cannot interbreed. For example, different populations of trout live in Lake Sevan, but they go to different rivers that flow into this lake to spawn.

Insert the missing terms from the proposed list into the text “Fluctuations in the number of individuals”, using numerical notations for this. The number of individuals in populations is not constant. Its periodic oscillations are called (A). Their significance for evolution lies in the fact that as the population grows, the number of mutant individuals increases as many times as the number of individuals increases. If the number of individuals in a population decreases, then it (B) becomes less diverse. In this case, as a result of (B), individuals with certain (D) may disappear from it.
1) population wave
2) struggle for existence
3) variability
4) gene pool
5) natural selection
6) genotype
7) phenotype
8) heredity

Answer

Choose one, the most correct option. Combinative variability is referred to as
1) the driving forces of evolution
2) directions of evolution
3) the results of evolution
4) stages of evolution

Answer

1. Establish the sequence of formation of adaptations in a plant population during the process of evolution. Write down the corresponding sequence of numbers.
1) consolidation of a new trait by stabilizing selection
2) the action of the driving form of selection on individuals in the population
3) change in the genotypes of individuals in the population under new conditions
4) change in the habitat conditions of the population

Answer

2. Establish the sequence of formation of plant fitness in the process of evolution. Write down the corresponding sequence of numbers.
1) reproduction of individuals with useful changes
2) the occurrence of various mutations in the population
3) struggle for existence
4) preservation of individuals with hereditary changes useful for given environmental conditions

Answer

3. Establish the sequence of microevolution processes. Write down the corresponding sequence of numbers.
1) the action of driving selection
2) the appearance of beneficial mutations
3) reproductive isolation of populations
4) struggle for existence
5) formation of a subspecies

Answer

4. Establish the sequence of action of the driving forces of evolution. Write down the numbers under which they are indicated.
1) struggle for existence
2) reproduction of individuals with useful changes
3) the appearance of various hereditary changes in the population
4) preservation of predominantly individuals with hereditary changes useful in given environmental conditions
5) formation of adaptation to the environment

Answer

5. Establish the sequence of formation of the population of the dark-colored birch moth butterfly in polluted industrial areas.
1) the appearance of differently colored butterflies in the offspring
2) an increase in the number of butterflies with darker colors
3) preservation as a result of natural selection of butterflies with dark colors and death with light colors
4) the emergence of a population of dark-colored butterflies

Answer

6n. Establish the sequence of processes during speciation. Write down the corresponding sequence of numbers.
1) distribution of useful traits in isolated populations
2) natural selection of individuals with useful traits in isolated populations
3) rupture of the species’ range due to changes in relief
4) the emergence of new traits in isolated populations
5) formation of new subspecies

Answer

1. Indicate the sequence of processes of geographic speciation. Write down the corresponding sequence of numbers
1) distribution of a trait in a population
2) the appearance of mutations in new living conditions
3) spatial isolation of populations
4) selection of individuals with useful changes
5) formation of a new species

Answer

2. Determine the sequence of processes characteristic of geographic speciation
1) formation of a population with a new gene pool
2) the appearance of a geographical barrier between populations
3) natural selection of individuals with characteristics adaptive to given conditions
4) the appearance of individuals with new characteristics in an isolated population

Answer

3. Indicate the sequence of processes during geographic speciation
1) accumulation of mutations in new conditions
2) territorial isolation of the population
3) reproductive isolation
4) formation of a new species

Answer

4. Indicate the sequence of stages of geographic speciation
1) divergence of traits in isolated populations
2) reproductive isolation of populations
3) the emergence of physical barriers in the range of the original species
4) the emergence of new species
5) formation of isolated populations

Answer

5. Establish the sequence of stages of geographic speciation. Write down the corresponding sequence of numbers.
1) the appearance of new random mutations in populations
2) territorial isolation of one population of a species
3) change in the gene pool of the population
4) preservation by natural selection of individuals with new characteristics
5) reproductive isolation of populations and formation of a new species

Answer

Establish the sequence of stages of ecological speciation. Write down the corresponding sequence of numbers.
1) ecological isolation between populations
2) biological (reproductive) isolation
3) natural selection in new environmental conditions
4) the emergence of ecological races (ecotypes)
5) the emergence of new species
6) development of new ecological niches

Answer

Choose one, the most correct option. In ecological speciation, as opposed to geographic speciation, a new species arises
1) as a result of the collapse of the original area
2) inside the old range
3) as a result of expansion of the original range
4) due to genetic drift

Answer

Choose one, the most correct option. An evolutionary factor contributing to the accumulation of various mutations in a population is
1) intraspecific struggle
2) interspecific struggle
3) geographical isolation
4) limiting factor

Answer

Choose one, the most correct option. Hereditary variability in the process of evolution
1) fixes the created attribute
2) is the result of natural selection
3) supplies material for natural selection
4) selects adapted organisms

Answer

Choose one, the most correct option. An example of ecological speciation
1) Siberian and Daurian larch
2) white hare and brown hare
3) European and Altai squirrel
4) populations of Sevan trout

Answer

Choose three correct answers out of six and write down the numbers under which they are indicated. Indicate the characteristics that characterize natural selection as the driving force of evolution
1) Source of evolutionary material
2) Provides a reserve of hereditary variability
3) The object is the phenotype of an individual
4) Provides selection of genotypes
5) Directional factor
6) Random factor

Answer

1. Establish a correspondence between the process occurring in nature and the form of struggle for existence: 1) intraspecific, 2) interspecific
A) competition between individuals of a population for territory
B) the use of one type by another
B) competition between individuals for the female
D) displacement of a black rat by a gray rat
D) predation

Answer

2. Establish a correspondence between an example of the struggle for existence and the form to which this struggle belongs: 1) intraspecific, 2) interspecific. Write numbers 1 and 2 in the correct order.
A) identification of nesting sites in the forest by crossbills
B) the bovine tapeworm uses cattle as a habitat
B) competition between males for dominance
D) displacement of a black rat by a gray rat
D) fox hunting for voles

Answer

3. Establish a correspondence between examples and types of struggle for existence: 1) intraspecific, 2) interspecific. Write numbers 1 and 2 in the order corresponding to the letters.
A) displacement of a black rat by a gray rat
B) behavior of male moose during the mating season
B) fox hunting mice
D) growth of beet seedlings of the same age in one bed
D) the behavior of a cuckoo in the nest of another bird
E) rivalry between lions in the same pride

Answer

4. Establish a correspondence between the processes occurring in nature and the forms of struggle for existence: 1) interspecific, 2) intraspecific. Write numbers 1 and 2 in the order corresponding to the letters.
A) marking of territory by a male field mouse
B) mating of male wood grouse in the forest
C) inhibition of seedlings of cultivated plants by weeds
D) competition for light between spruce trees in the forest
D) predation
E) displacement of the black cockroach by the red one

Answer

1. Establish a correspondence between the cause of speciation and its method: 1) geographical, 2) ecological. Write numbers 1 and 2 in the correct order.
A) expansion of the range of the original species
B) stability of the range of the original species
C) division of the species' range by various barriers
D) diversity of variability of individuals within the range
D) diversity of habitats within a stable range

Answer

2. Establish a correspondence between the features of speciation and their methods: 1) geographical, 2) ecological. Write numbers 1 and 2 in the order corresponding to the letters.
A) isolation of populations due to a water barrier
B) isolation of populations due to different timing of reproduction
B) isolation of populations due to the emergence of mountains
D) isolation of populations due to large distances
D) isolation of populations within the range

Answer

3. Establish a correspondence between the mechanisms (examples) and methods of speciation: 1) geographical, 2) ecological. Write numbers 1 and 2 in the order corresponding to the letters.
A) expansion of the range of the original species
B) preservation of a single original range of the species
C) the appearance of two species of gulls in the North and Baltic seas
D) formation of new habitats within the original range
E) the presence of populations of Sevan trout that differ in spawning periods

Answer

4. Establish a correspondence between the characteristics and methods of speciation: 1) geographical, 2) ecological. Write numbers 1 and 2 in the order corresponding to the letters.
A) long-term persistence of the existence of the range of the original species
B) division of the range of the original species by an insurmountable barrier
C) different food specializations within the original range
D) division of the area into several isolated parts
D) development of various habitats within the original range
E) isolation of populations due to different timing of reproduction

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5. Establish a correspondence between the characteristics and methods of speciation: 1) geographical, 2) ecological. Write numbers 1 and 2 in the order corresponding to the letters.
A) habitat stability
B) the emergence of physical barriers
C) the emergence of populations with different periods of reproduction
D) isolation of populations in the forest by road
D) range expansion

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1. Select three sentences from the text that describe the ecological method of speciation in the evolution of the organic world. Write down the numbers under which they are indicated. (1) Reproductive isolation causes microevolution. (2) Free crossing allows for the exchange of genes between populations. (3) Reproductive isolation of populations can occur within the same range for various reasons. (4) Isolated populations with different mutations adapt to the conditions of different ecological niches within the former range. (5) An example of such speciation is the formation of buttercup species that have adapted to life in the field, meadow, and forest. (6) The species serves as the smallest genetically stable supraorganismal system in living nature.

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2. Read the text. Select three sentences that describe the processes of ecological speciation. Write down the numbers under which they are indicated. (1) During speciation, the range of a species is divided into fragments. (2) There are several populations in Lake Sevan, differing in spawning periods. (3) Speciation may be associated with a change in the ecological niche of a species. (4) If polyploid forms are more viable than diploid forms, they can give rise to a new species. (5) Several species of tits live in Moscow and the Moscow region, differing in their methods of obtaining food.

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3. Read the text. Select three sentences that describe ecological speciation. Write down the numbers under which they are indicated. (1) Species in nature exist in the form of separate populations. (2) Due to the accumulation of mutations, a population can be formed under changed conditions in the original area. (3) Sometimes microevolution is associated with a gradual expansion of the range. (4) Natural selection consolidates persistent differences between plants of different populations of the same species, occupying the same habitat, but growing in a dry meadow or in a river floodplain. (5) For example, in this way the types of buttercups that grow in forests, meadows, and along river banks were formed. (6) Spatial isolation caused by mountain building may be a factor in speciation.

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4. Read the text. Select three sentences that describe ecological speciation. Write down the numbers under which they are indicated. (1) Speciation can occur within a single contiguous range if organisms inhabit different ecological niches. (2) The causes of speciation are discrepancies in the timing of reproduction in organisms, the transition to new food without changing the habitat. (3) An example of speciation is the formation of two subspecies of the greater rattle growing in the same meadow. (4) Spatial isolation of groups of organisms can occur when the range expands and the population enters new conditions. (5) As a result of adaptations, South Asian and Eurasian subspecies of the great tit were formed. (6) As a result of isolation, endemic island species of animals were formed.

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5. Read the text. Select three sentences that fit the description of ecological speciation. Write down the numbers under which they are indicated. (1) The result of the action of the driving forces of evolution is the spread of the species into new areas. (2) Speciation may be associated with an expansion of the range of the original species. (3) Sometimes it occurs as a result of the rupture of the original range of a species by physical barriers (mountains, rivers, etc.) (4) New species can master specific living conditions. (5) As a result of food specialization, several species of tits were formed. (6) For example, the great tit feeds on large insects, and the tufted tit eats the seeds of coniferous trees.

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1. Read the text. Select three sentences that describe the features of geographic speciation. Write down the numbers under which the selected statements are indicated. (1) Associated with spatial isolation due to range expansion or fragmentation, as well as human activity. (2) Occurs in the event of a rapid increase in the chromosome set of individuals under the influence of mutagenic factors or errors in the process of cell division. (3) Occurs more often in plants than in animals. (4) Occurs through the dispersal of individuals to new territories. (5) In different living conditions, ecological races are formed, which become the ancestors of new species. (6) Polyploid viable forms can give rise to a new species and completely displace a diploid species from its range.

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2. Select three sentences from the text that characterize the geographical method of speciation in the evolution of the organic world. Write down the numbers under which they are indicated. (1) The exchange of genes between populations during the reproduction of individuals preserves the integrity of the species. (2) If reproductive isolation occurs, crossing becomes impossible and the population takes the path of microevolution. (3) Reproductive isolation of populations occurs when physical barriers arise. (4) Isolated populations expand their range by maintaining adaptations to new living conditions. (5) An example of such speciation is the formation of three subspecies of the great tit, which colonized the territories of eastern, southern and western Asia. (6) The species serves as the smallest genetically stable supraorganismal system in living nature.

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3. Read the text. Select three sentences that describe geographic speciation. Write down the numbers under which they are indicated. (1) Speciation is the result of natural selection. (2) One of the reasons for speciation is the discrepancy in the timing of reproduction of organisms and the occurrence of reproductive isolation. (3) An example of speciation is the formation of two subspecies of the greater rattle growing in the same meadow. (4) Spatial isolation of groups of organisms may be accompanied by range expansion, in which populations find themselves in new conditions. (5) As a result of adaptations, South Asian and Eurasian subspecies of the great tit were formed. (6) As a result of isolation, endemic island species of animals were formed.

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4. Read the text. Select three sentences that describe geographic speciation. Write down the numbers under which they are indicated. (1) A species in nature occupies a certain area and exists in the form of separate populations. (2) Due to the accumulation of mutations, a population with a new gene pool can be formed within the original area. (3) Expansion of the species' range leads to the emergence of isolated new populations at its borders. (4) Within the new boundaries of the range, natural selection consolidates persistent differences between spatially separated populations. (5) Free interbreeding between individuals of the same species is disrupted as a result of the appearance of mountain barriers. (6) Speciation is gradual.

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Choose three correct answers out of six and write down the numbers under which they are indicated. The processes leading to the formation of new species in nature include
1) mitotic cell division
2) spasmodic mutation process

4) geographical isolation
5) asexual reproduction of individuals
6) natural selection

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Establish a correspondence between the example and the method of speciation that this example illustrates: 1) geographical, 2) ecological. Write numbers 1 and 2 in the correct order.
A) the habitat of two populations of common perch in the coastal zone and at great depths of the lake
B) the habitat of different populations of blackbirds in dense forests and near human habitation
C) disintegration of the May lily of the valley range into isolated areas due to glaciation
D) the formation of different types of tits based on food specialization
D) the formation of Dahurian larch as a result of the expansion of the range of Siberian larch to the east

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Choose three options. Under the influence of what evolutionary factors does the process of ecological speciation occur?
1) modification variability
2) fitness
3) natural selection
4) mutational variability
5) struggle for existence
6) convergence

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Choose three options. What factors are the driving forces of evolution?
1) modification variability
2) mutation process
3) natural selection
4) adaptability of organisms to their environment
5) population waves
6) abiotic environmental factors

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1) crossing over
2) mutation process
3) modification variability
4) insulation
5) variety of species
6) natural selection

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Choose three options. The driving forces of evolution include
1) isolation of individuals
2) adaptability of organisms to the environment
3) variety of species
4) mutational variability
5) natural selection
6) biological progress

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Read the text. Select three sentences that indicate the driving forces of evolution. Write down the numbers under which they are indicated. (1) The synthetic theory of evolution states that species live in populations in which evolutionary processes begin. (2) It is in populations that the most intense struggle for existence is observed. (3) As a result of mutational variability, new characteristics gradually arise. Including adaptations to environmental conditions - idioadaptations. (4) This process of gradual emergence and retention of new characters under the influence of natural selection, leading to the formation of new species, is called divergence. (5) The formation of new large taxa occurs through aromorphosis and degeneration. The latter also leads to the biological progress of organisms. (6) Thus, the population is the initial unit in which the main evolutionary processes occur - changes in the gene pool, the appearance of new characteristics, the emergence of adaptations.

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Establish a correspondence between the factors of speciation and its method: 1) geographical, 2) ecological, 3) hybridogenic. Write numbers 1-3 in the correct order.
A) polyploidization of hybrids from inbreeding
B) differences in habitats
B) division of the area into fragments
D) the habitat of different types of lily of the valley in Europe and the Far East
D) food specialization

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Analyze the table “Struggle for Existence”. For each lettered cell, select the appropriate term from the list provided. Write down the selected numbers in the order corresponding to the letters.
1) combating environmental conditions
2) limited natural resources
3) combating unfavorable conditions
4) various ecological criteria of the species
5) seagulls in colonies
6) males during the mating season
7) birch and tinder
8) the need to choose a sexual partner

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Choose one, the most correct option. Separation of populations of the same species according to reproductive timing can lead to
1) population waves
2) convergence of features
3) intensification of interspecies struggle
4) ecological speciation

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Select two sentences that indicate processes NOT related to the intraspecific struggle for existence. Write down the numbers under which they are indicated.
1) Competition between wolves of the same population for prey
2) Fight for food between gray and black rats
3) Destruction of young animals with excess population size
4) The struggle for dominance in a pack of wolves
5) Reduction of leaves in some desert plants

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