Examples of the main laws of evolution. Patterns and rules of evolution
Chikina Natalya Alexandrovna
MBOU gymnasium No. 1 of the city of Lipetsk
Biology
Lesson topic: Basic laws of evolution. Macroevolution.
Goals:
Educational. To consolidate knowledge about the basic laws of evolution. Practice the basic concepts of the topic.
Educational. Continue the formation of skills to analyze information and identify aromorphoses, idioadaptation and degeneration, and draw conclusions on the work done.
Educational: to instill the skills of interested learning.
Lesson type: knowledge development lesson
Equipment: herbarium, tables, drawings, texts, tests.
During the classes
Knowledge update.
Development of the formulation of the basic concepts:
(work on the worksheet, annex 1, presentation slides 2-10)
Macroevolution.
biological progress
biological regression
Aromorphosis
Idioadaptation
Degeneration
Divergence
Convergence
Parallelism
Homologous Organs
Similar bodies
Lesson work
1. Frontal work of students with text.
The main feature of the angiosperm group is the presence of flowers and fruits. The ovule of flowering plants is protected from adverse effects by the ovary. Fruit formation ensured successful seed germination under adverse conditions. The structure of organs in flowering plants reaches the greatest complexity, and tissues are characterized by a high degree of specialization.
Clover has small flowers collected from most of the inflorescence - the head. A characteristic feature of the cactus is the fleshy stem and thorn leaves.
Birds have a four-chambered heart, feather cover, they are warm-blooded. In the eggs of birds, the supply of nutrients has increased.
The big motley woodpecker is a very motley bird. Its predominant color consists of a combination of black and white tones. The tail of a large spotted woodpecker is of medium length, pointed and very hard, since it serves mainly as a support when the bird climbs a tree trunk. Falcons are birds of prey. Adult birds are distinguished by a hook-shaped beak and narrow wedge-shaped wings, thanks to which they are able to deftly maneuver and develop unusually high speed in a dive flight.
2. Whiteboard work.
1. List the main aromorphoses of plants (using herbarium specimens, slides 11-12)
2. List the main aromorphoses of vertebrates (slides 13-14).
3. Frontal work with tests. Working out the tasks of part A.
1. Reduction in the number and range of the Ussuri tiger in the modern era - an example
A) biological progress B) biological regression
C) idioadaptation D) aromorphosis
2. The appearance of a four-chambered heart, warm-bloodedness, and a developed cerebral cortex in ancient mammals - an example
A) idioadaptation B) aromorphosis
C) biological progress D) biological regression
3. Which trait is NOT considered aromorphosis in mammals
A) hairline B) four-chambered heart
C) diaphragm D) shortened tail
4. Give an example of aromorphosis
A) flattening of the body in bottom fish
B) the appearance of protective coloration in pike
C) intestinal reduction in pork tapeworm
D) the emergence of multicellularity
5. The increase in the number of gray crows in settlements - an example
A) aromorphosis B) degeneration
C) biological regression D) biological progress
7. The appearance in amphibians in the process of evolution of a three-chambered heart, two circles of blood circulation - an example of the development of the organic world along the way
A) aromorphosis B) idioadaptation
C) degeneration D) biological progress
8. The result of idioadaptation in birds is considered
A) the appearance of a feather cover
B) the appearance of a four-chambered heart
C) a variety of beak shapes
D) the formation of a highly developed nervous system
10. Indicator of the biological progress of the species
A) symbiosis B) mutual assistance
C) competition D) high numbers
11. Indicate the INCORRECT statement: ""Aromorphosis leads to""
A) the general rise of the organization
B) increase the intensity of life
C) the formation of devices of wide significance
D) the formation of private devices
12. Degeneration is
A) evolutionary changes leading to simplification of the organization
B) cases of manifestation of signs of ancestors in individual individuals
C) major evolutionary changes leading to a general rise in the organization
D) small evolutionary changes that ensure adaptability to the environment
13. Which of the following indicators does not characterize biological progress?
A) ecological diversity B) care for offspring
C) wide range D) high abundance
15. What systematic group of animals is formed as a result of large aromorphoses?
A) species B) class C) family D) genus
Working out questions from part B.
Q 1. Which of the following examples are classified as aromorphoses?
1) the formation of a gnawing mouth apparatus in the cockchafer
2) the appearance of trachea in arthropods
3) the appearance of the third germ layer in worms
4) folding of the cerebral cortex of mammals
5) development of fangs in carnivorous mammals
6) reduction to two fingers in ostriches
B 3. Specify signs of general degeneration in animals..
1) general rise of the organization
2) decrease in the intensity of vital activity
3) lowering the level of organization
5) devices of a private nature
6) simplification of the nervous system due to a sedentary lifestyle
B 4. Match the direction of evolution and its characteristics with the direction of biological progress and an example
Direction
A. the presence of burrowing limbs in a mole
1. Aromorphosis
2. Idioadaptation
B. the formation of an elephant's trunk
3. Degeneration
D. loss of digestive organs in tapeworms
D. reduction of sensory organs in bovine tapeworm
E. feeding of young with milk in mammals
B 5. Match the direction of evolution and its characteristics.
Characteristic
Direction of evolution
A. increasing biodiversity
1. biological progress
B. narrowing of species ranges
2. biological regression
B. reduction in the number of individuals of a species
D. fitness enhancement
D. species extinction
B 6. Establish the sequence of the emergence of animals in the process of historical development.
A) flatworms
B) unicellular animals
B) coelenterates
D) annelids
D) colonial unicellular organisms
E) arthropods
AT 7.Establish the sequence of appearance of groups of chordates in the process of evolution.
lobe-finned fish B) reptiles
stegocephalians
D) non-cranial chordates
D) birds and mammals
AT 8. Establish the sequence of aromorphoses in the evolution of plants that led to the emergence of more highly organized forms.
A) cell differentiation and the appearance of tissues
B) the appearance of a seed
B) the formation of a flower and a fruit
D) the appearance of photosynthesis
D) the formation of the root system and leaves
Working out questions from part C.
C1. What aromorphoses allowed birds to spread widely in the ground-air habitat? List at least three examples.
Answer:
1) features of the structure and functions associated with flight: hollow bones, the transformation of the forelimbs into wings, the rapid digestion of food, etc .;
2) features that ensured a high level of metabolism and warm-bloodedness: a 4-chambered heart, a special structure of the respiratory organs, consumption of a large amount of food, etc.;
3) development of the central nervous system, complex behavior (flights, caring for offspring, etc.).
C2. What characterizes biological progress in flowering plants? List at least 3 features.
Answer:
1) a wide variety of populations and species; 2) wide settlement on the globe; 3) adaptability to life in different environmental conditions.
C3. What aromorphoses ensured warm-bloodedness in mammals? Specify at least 3 aromorphic features.
Answer: 1)4 chambered heart; 2) Alveolar lungs; 3) Hairline.
C4. Why can high fecundity of individuals lead to the biological progress of a species? List at least three reasons.
Answer: 1) increases the abundance of the species; 2) promotes the dispersal of the species over large areas; 3) leads to the formation of diverse populations.
Check of knowledge. control test
Part A. Choose one correct answer. Write down the chosen number in the answer sheet
A1. The development of wings in birds, which provided them with the opportunity to fly, is characterized as:
1) convergence 3) idioadaptation
2) aromorphosis 4) degeneration
1) the appearance of spores 3) the formation of the fetus
2) seed formation 4) leaf modification
1) aromorphosis 3) biological regression
2) idioadaptation 4) biological progress
A4. Which of the organisms are in a state of biological regression:
1) white cranes 3) staphylococcus bacteria
2) liver flukes 4) houseflies
1) loss of coat by elephants
2) the appearance of eggs in reptiles and their subsequent development on land
3) elongation of the limbs of the horse
4) the appearance of the peacock's tail
A6. Example of idioadaptation:
A7. An example of general degeneration:
1) turning cactus leaves into thorns
2) loss of circulatory organs in flatworms
3) the occurrence of warm-bloodedness
4) the appearance of jaws in fish
A8. The decline in the number and range of the Ussuri tiger is an example:
1) biological regression
2) degeneration
3) biological progress
4) aromorphosis
A9. Which of the named aromorphoses was formed in the process of evolution of the organic world later than the others:
1) spine 3) 2 circles of blood circulation
2) warm-bloodedness 4) sexual reproduction process
A10. The flat body shape of the flounder is an example:
1) aromorphosis 3) general degeneration
2) idioadaptation 4) biological progress
A11. An example of degeneration is the absence of:
1) dodder roots 3) snake limbs
2) teeth in birds 4) gills in adult frogs
Part B.
In tasks B1-B3, choose three correct answers out of six. Write the selected numbers on the answer sheet without spaces or other symbols.
B1. Aromorphoses include:
1) the formation of tubers in potatoes
3) the appearance of a streamlined body shape in a dolphin
4) the appearance of tissues and organs in plants
5) the appearance of a flower in angiosperms
6) the formation of trailers in the fetus of the series
AT 2. Which of the following examples are idioadaptations?
1) development of educational tissues in plants
2) the presence of trapping devices in insectivorous plants
4) the appearance of triploid endosperm in angiosperms
5) small, dry pollen in wind-pollinated plants
6) glandular hairs on fragrant geranium leaves
Q3. Which of the following examples illustrate general degeneration:
1) lack of lungs in fish
2) lack of vision in animals living underground
4) the absence of a tail in a frog
5) the transformation of the roots of the dodder plant into suckers
6) loss of intestine by tapeworms
Answer matrix.
Aromorphoses
Idioadaptation
Degeneration
Progress and regression in evolution
Homework.
Repeat the topic from the textbook and notes in the notebook.
Answer the question.
Why not only aromorphosis, but also idioadaptation and degeneration can lead to biological progress? Give at least three pieces of evidence.
Basic laws of evolution
Evolution proceeds unevenly, i.e. at different speeds in different periods of the Earth's history, but tends to accelerate.
For example, the first living beings appeared about 3.8 billion years ago, multicellular - 1.3 billion years ago, mammals and birds - 200 million years ago, primates - 60 - 65 million years ago, the genus Man - about 4 million years ago, Homo sapiens - about 80 thousand years ago.
The evolution of different groups occurs at different rates. It is customary to estimate the rate of speciation in the number of generations. Thus, the rapid formation of new species, associated with large chromosomal rearrangements, takes up to several tens of thousands of generations. The slow accumulation of adaptations gives a new species after several hundred thousand generations.
Evolution does not always go from simple to complex, there is also a direction that is accompanied by a simplification of the structure. An example of such a pathway is general degeneration.
The low mobility and passive type of feeding of bivalves led to the disappearance of the head.
Evolution is an irreversible process(the rule of irreversibility of evolution), therefore, organisms cannot return to their previous state.
The ichthyosaurs that returned to the water did not become fish, but retained the structural features of reptiles.
In some organisms, including humans, in ontogeny, as a result of a developmental disorder, it is possible for certain traits to appear that existed in the ancestors, but were lost in the process of evolution. These signs are called atavisms .
Atavism(lat. atavus- a distant ancestor) - the appearance in organisms of signs that were absent in their immediate ancestors, but existed in very distant ancestors. An example of atavism is the development of the caudal appendage in humans; the appearance in the horse of two additional fingers on the sides of the developed third finger.
In the process of development of the individual, the features of the organization of the ancestors are repeated to some extent, but disturbances in normal development can lead to the fact that in the adult organism the signs of the ancestors, which appear in the embryo and usually disappear in the course of further development, remain for life.
An example of such an atavism is the appearance in humans of a cervical fistula, reminiscent of the gill slit of the ancestors of mammals - fish and amphibians. This also includes polymastia in humans (the formation of a greater than normal number of pairs of mammary glands), three-fingered horses, etc.
Atavisms also include the appearance of signs of distant ancestors during the regeneration of organs. In this case, the latter are recreated with features characteristic of more ancient forms. For example, during the regeneration of the tail in lizards, the rings of its scales are sometimes formed in a more primitive form.
Progressive specialization rule- this is a phenomenon, as a result of which any group of living organisms, evolving along the path of adaptation to specific conditions, will continue to move along the path of deepening specialization.
The genetic basis of this rule lies in the fact that in the process of natural selection under the conditions of a given adaptive zone, those genes that do not correspond to it are eliminated from the population.
An example is the adaptation of gibbons adapted to an arboreal lifestyle. They lack the grasping tail found in other tree monkeys, so they move by jumping from branch to branch with their elongated forelimbs. Their thumb is significantly reduced and the hand is practically incapable of manipulating small objects. When moving on the ground, the hands of gibbons are no longer involved in locomotion.
An example of progressive specialization is the morphological transformation of limbs in the evolutionary branch of horses.
In the transition to life in open spaces with dense soil, the number of fingers gradually decreased in the ancestors of the horse, until there was only one left. This feature of the structure does not allow modern horses to inhabit other biotopes.
The principle of integration- the unification of individual structures into a holistic organism. Integration is the expedient association and coordination of the actions of different parts of an integral living system. It manifests itself in the unification of organs into functionally unified systems that provide one of the aspects of the life of the organism.
The four-chambered mammalian heart is an example of an integrated structure: each of its departments performs a specific function that does not make sense in isolation from the functions of other departments.
Principle of differentiation is the division of a homogeneous structure into separate parts that acquire a specific structure. Thus, the complication of the structure is always associated with the complication of functions and the specialization of individual parts.
An example of phylogenetic differentiation is the evolution of the circulatory system in the chordate type.
Rudiments(lat. rudimentum- germ, fundamental principle), or vestigial organs- relatively simplified, underdeveloped structures that have lost their main significance in the body in the process of phylogenesis.Rudiments are laid during embryonic development, but do not fully develop.
Examples of rudiments are: the fibula in birds, the eyes in some cave and burrowing animals, the remains of hair and pelvic bones in a number of cetaceans.
In humans, the rudiments include the tail vertebrae, the hairline of the body, the ear muscles, and the appendix. Unlike atavisms, rudiments are found in all individuals of the species.
Thus, biological evolution (lat. evolution- "deployment") is a process of constant and natural selection-directed change in the forms of organisms on Earth, ensuring their adaptability to environmental conditions. Such adaptability is achieved by selecting from a variety of random changes those that facilitate the survival of organisms in specific environmental conditions.
Patterns of evolution
| Names of patterns | The semantic meaning of patterns | Causes and explanations for patterns |
| irreversible nature (L. Dollo 1893) |
Return to original condition is impossible |
Population evolves, entire gene complexes are selected |
| Progressive sophistication of life forms | General direction of evolution | Divergence and extinction of many branches while maintaining one, giving rise to a new group |
| Evolution is an unprogrammed process | Lack of focus | Direction, speed and stroke development of nature are given and carried out by natural selection. |
| Uneven evolution | Different rates of evolution of different groups of organisms | Stabilizing selection preserves "living fossils", driving - forms new adaptations in populations and species |
| Accelerating the pace of evolution | Each next epoch in the development of the Earth is shorter than the previous one. | From prokaryotes to the first multicellular - 2.5 billion years. The first terrestrial organisms - 400 million years. Development of mammals and birds - for 100 million years. The development of Homo sapiens - 60 thousand years. |
Synthetic theory of evolution. In development synthetic theory of evolution contributed by many scientists. The term “synthetic evolution” comes from the title of the book by the English evolutionist J. Huxley “Evolution: A Modern Synthesis”, published in 1942.
The main provisions of the synthetic theory of evolution- The material for evolution is hereditary changes - mutations (as a rule, genes) and their combinations.
- The main driver of evolution is natural selection.
- The unit of evolution is the population.
- Evolution is in most cases divergent in nature, i.e. one taxon can become the ancestor of several daughter taxa.
- Evolution is gradual and long lasting. Speciation as a stage of the evolutionary process is a successive change of one temporary population by a succession of subsequent temporary populations.
- A species consists of subspecies and populations.
- The species exists as a holistic entity.
- Macroevolution follows the path of microevolution. The evolution of groups of species of living organisms is characterized by the same prerequisites and driving forces as for microevolution.
- Any taxon is usually monophyletic in origin.
- Evolution has an undirected character, that is, it does not go in the direction of any final goal.
Evolution is a historical process of the development of living nature, which depends on the interaction of many external and internal factors with the leading role of selection.
188. Fill in the table "Types of evolutionary changes"
Types of evolutionary change Characteristic Examples Parallelism The result is the appearance of similar features in related organisms. cetaceans and pinnipeds, independently of each other, moved to living in the aquatic environment and acquired flippers. Similarities in the structure of African and American porcupines Convergence Two or more unrelated species become more and more similar to each other. This is the result of adaptation to similar environmental conditions. Dolphin, shark and penguin look alike; marsupial flyer and flying squirrel. The presence of wings in butterflies and birds Divergence Represents an evolutionary tree with divergent branches. The common ancestor gave rise to two or more forms, which, in turn, became the ancestors of many species and genera. Divergence - divergent evolution - almost always reflects the expansion of adaptation to new living conditions The class of mammals broke up into orders, the representatives of which differ in structure, ecological features, in the nature of physiological and behavioral adaptations (insectivores, predators, cetaceans)
189. Look at the picture in your textbook that illustrates an example of convergent evolution. Suggest the reasons why chordates belonging to different classes have a similar morphological structure
Unrelated species (in the figure) became more and more similar to each other in the course of evolution. This is the result of adaptations to similar environmental conditions - large aquatic animals have adapted to fast swimming
190. Fill in the table "Directions of evolution"
191. The evolutionary changes in the structure and life of organisms are listed below:
A) the process of photosynthesis
B) the emergence of chordates
C) the emergence of multicellularity
D) the appearance of a flower
E) the appearance of a thick undercoat in mammals in winter
E) change in coat color in a hare in winter
H) loss of the digestive system by tapeworms
I) loss of color in some species of shrimp
K) modification of the leaves of a cactus
Write out the letters that indicate the listed changes, in accordance with their belonging to the main directions of evolution
Aromorphoses: A, B, C, D
Idioadaptations: D, E, K
Degenerations: F, G, I
>> Basic patterns of evolution
Basic laws of evolution.
1. What is evolution?
2. What facts support the evolutionary doctrine?
When constructing phylogenetic series, evolutionary biologists, in addition to paleontological data, widely use the comparative method, with which they establish similarities in the structure of organisms, their biochemical reactions, reproduction characteristics, or other properties that can be used to judge the developmental paths of a group from a common ancestor.
Lesson content Lesson outline and support frame Lesson presentation Accelerative methods and interactive technologies Closed exercises (for teacher use only) Assessment Practice tasks and exercises, self-examination workshops, laboratory, cases level of complexity of tasks: normal, high, olympiad homework Illustrations illustrations: video clips, audio, photographs, graphics, tables, comics, multimedia essays chips for inquisitive cribs humor, parables, jokes, sayings, crossword puzzles, quotes Add-ons external independent testing (VNT) textbooks main and additional thematic holidays, slogans articles national features glossary other terms Only for teachersMorphofunctional features of the organization of living organisms are determined by two factors: physiological needs and specific environmental conditions. With all the variety of particular features of the structure and adaptations of organisms to the external environment, some general patterns of the evolutionary process can be distinguished.
The data of taxonomy, paleontology, comparative anatomy and other biological disciplines make it possible to restore the course of the evolutionary process at the supraspecific level with great accuracy. Among the forms of evolution of groups of living organisms can be distinguished: divergence, convergence and parallelism.
Divergence. The emergence of new forms is always associated with adaptation to local geographical and ecological conditions of existence. Thus, the class of mammals consists of numerous orders, the representatives of which differ in the type of food they consume, the characteristics of their habitats, i.e. living conditions (insectivores, bats, carnivores, artiodactyls, cetaceans, etc.). Each of these orders includes suborders and families, which in turn are characterized not only by specific morphological features, but also by ecological features (forms: running, galloping, climbing, burrowing, swimming). Within any family, species and genera differ in their mode of life, food objects, and so on. As Darwin pointed out, the whole evolutionary process is based on divergence. Not only species can diverge, but also genera, families, and orders. Divergence of any scale is the result of natural selection in the form of group selection (species, genera, families, etc. are preserved or eliminated). Group selection is also based on individual selection within a population. The extinction of a species occurs due to the death of individual individuals.
The peculiarity of the morphological features of organisms acquired in the process of divergence has a certain common basis in the form of a gene pool of related forms. The limbs of all mammals, although they differ from each other, have a single structural plan and represent a five-fingered limb. Therefore, organs that correspond to each other in structure and have a common origin, regardless of the function they perform, are called homologous (Fig. 20.5). Examples of homologous organs in plants are pea tendrils, barberry needles, cactus spines - all of these are modified leaves. Lily of the valley rhizome, potato tubers, onion bulb (underground shoots) are also homologous.
Rice. 20.5. Homologous organs: limbs of different groups of vertebrates
Under the same conditions of existence, animals belonging to different systematic groups can acquire a similar structure. Such a similarity in structure arises with a similarity of functions and is limited only to organs directly related to the same environmental factors. In vertebrates, convergent similarities are found in the limbs of marine reptiles and mammals. The same way of life of marsupial and placental mammals led them, independently of each other, to the similarity of many structural features. The European mole and the marsupial mole, the marsupial flyer and the flying squirrel are similar. The marsupial wolf resembles a real predator. In vertebrates, convergent similarities are found in the limbs and body shape of reptiles and mammals (Fig. 20.6). However, the historical organization as a whole never converges. The convergence of signs affects mainly only those organs that are directly related to similar environmental conditions.
Rice. 20.6. Convergence: similarities in body and limb shape in fast-swimming animals: sharks (A), ichthyosaur (B) and dolphins (V, D)
Convergence is also observed in groups of animals that are systematically far apart from each other. Airborne organisms have wings and other adaptations for flight. But the wings of a bird and a bat are modified limbs, and the wings of butterflies are outgrowths of the body wall (Fig. 20.7).
Organs that perform similar functions, but have a fundamentally different structure and origin, are called similar. Similar are the gills of cancer and fish, burrowing the limbs of the mole and the bear.
Examples of the emergence of convergent similarities in the structure of organs under the same environmental conditions are given by the adaptation of unrelated groups of animals - arthropods and vertebrates - to life on land. During the development of land, arthropods and vertebrates develop an adaptation to the preservation of water in the body - dense covers with a waterproof outer layer. Most aquatic animals are characterized by the excretion of nitrogen metabolism products in the form of ammonia with a large amount of water. In terrestrial animals, nitrogen is excreted in the form of uric acid, which makes it possible to reduce water consumption as much as possible. Thus, in the process of evolution, the physiological improvement of unrelated organisms is carried out in similar ways on the basis of non-homologous structures.
Rice. 20.7. Convergent similarity: bat wings (L), birds (B) insect (IN)
Parallelism. Parallelism is a form of convergent development characteristic of genetically close groups of organisms. For example, among mammals, cetaceans and pinnipeds independently of each other moved to living in an aquatic environment and acquired similar adaptations for movement in this environment - flippers. Unrelated mammals of the tropical zone, living on different continents in similar climatic conditions, have a known general similarity (Fig. 20.8).
Rice. 20.8. Convergent structural similarity in unrelated mammals inhabiting the rainforests of Africa (left) and South America (right):
A - pygmy hippopotamus; B - African deer; IN - pygmy antelope; G- gray duiker; D- pangolin; E - capybara; AND - pack; 3 - agouti;
AND - mazama; TO - giant armadillo