Ch. Darwin's doctrine of natural selection

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Charles Darwin's doctrine of natural selection. Lesson #7 Pokrovsky B.N,

Verification work No. 4 Option 1 2 3 4 Hereditary variability + + Mutation + + Artificial selection + + Selection + + Define the concepts Describe the methods for breeding new varieties and breeds

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D/h §5 Define the terms: Individual variability Struggle for existence (examples) Interspecific struggle (examples) Intraspecific struggle (examples) Natural selection (examples)

Work saves a person from three main evils: boredom, vice and need. Voltaire

Charles Darwin's doctrine of natural selection.

CONDITIONS Process SOURCE MEANS RESULT

Source of natural selection Individual variability - the appearance in the offspring as a result of mutation of new inherited traits that are absent in parental individuals.

Condition Excess progeny: Stellate sturgeon 400 thousand eggs Pike perch 300-900 thousand eggs Toad 10 thousand eggs Cod 10 million eggs Shepherd's purse 73 thousand seeds Henbane 450 thousand seeds All organisms leave an excess number of offspring. Most of the descendants die.

For example: If all born mice survived, then the offspring of one pair would occupy ALL the land within 7 years. as a result of a mutation.

The means of the struggle for existence is the diversity of the relationship of the organism with the environment. Natural selection - selective survival and reproduction of the fittest organisms

Intraspecific struggle is a competitive relationship between organisms of the same species.

Interspecific struggle is a competitive relationship between organisms of different species.

Fight against adverse conditions

On the topic: methodological developments, presentations and notes

The lesson "Charles Darwin's doctrine of natural selection" was developed on the basis of the basic textbook Mamontov S.G. Biology. General patterns. Grade 9: Textbook. For educational institutions / S.G. Mammoth, ...

Charles Darwin's doctrine of natural selection

This lesson contributes to the development of structural-logical thinking, the development of the ability to solve problems, compare and draw conclusions....

Biology teacher MBOU Lyceum "technical - economic" Novorossiysk Vdovichenko O.N. Charles Darwin's doctrine of natural selection. Grade 9 Lesson - presentation. Purpose: to show students the logic of building Ch. Darwin's evolutionary theory. Tasks: to reveal the mechanisms of evolution and their role in the development of the organic world; to form students' ability to compare different forms of natural selection. To develop some personal qualities of schoolchildren (the ability to reasonably express their opinions, hear and listen to others, work in a team, etc.) Type of lesson: combined Content: 1.Checking the quality of students' knowledge. Test tasks (2 options). 2. Study of new material. The logic of Ch. Darwin's theory. Types of struggle for existence. Forms of natural selection. 3. Consolidation of the studied material. Comparison table. 4. Homework. Verification tasks. Heredity. Option 1 Insert the missing words from the proposed list into the text. Heredity is the property of organisms to transmit traits to offspring from generation to generation during reproduction. The elementary unit of hereditary material is ... Its basis is the molecule .... The totality of all the hereditary material of an organism is ..., and the totality of its external and internal features form it .... Option 2 Find sentences in the text that contain biological errors. 1. The transmission of hereditary traits of an organism occurs only during sexual reproduction. 2. The carriers of hereditary information are usually DNA molecules concentrated in chromosomes. 3. All inherited genes will necessarily appear in the organism. The logic of Ch. Darwin's theory. Observed natural factors. Conclusion Mechanisms of evolution All organisms tend to multiply exponentially, but in nature there is a relative constancy of individuals of the same species. (Ex.) Therefore, something prevents organisms from surviving. This is the limitedness of vital resources and the uneven distribution of them. Struggle for existence. In nature, two identical individuals of the same species are not found. (Ex.) Consequently, organisms have the ability to acquire new features. Variability Individuals are in a constant struggle for existence and the fittest survive. Therefore, selection occurs in nature. Natural selection. Types of struggle for existence Intraspecific Interspecific With adverse conditions Natural selection The main driving factor of evolution, which is the result of the struggle for existence. The most adapted individuals of each species of organisms survive and leave offspring. Driving (directed) natural selection. Occurs against the background of changing environmental conditions, and there is a directional selection towards a changing factor (air temperature, water, humidity, etc.). Stabilizing natural selection. Occurs for a long time in practically unchanged conditions of life. In populations, species of organisms with a sufficient set of certain features characteristic of a particular environment are preserved. Forms of natural selection a Can manifest itself in dioecious animals, based on rivalry between individuals of the same sex for mating, and lead to sexual dimorphism (characteristic external signs linked to the sex of the animal). Disruptive natural selection Favors two or more directions of variation, i.e. predominantly receive extreme variants of devices. Conclusion. The result of natural selection is: the fitness of organisms, the formation of subspecies and species, there is a consistent change in organisms in the course of progressive evolution, the less adapted die out. Comparative characteristics of natural and artificial selection. Characteristics for comparison Artificial selection Natural selection Who selects? What is the selection material? How many signs are there? How long does it take? Why? Who benefits? What is the result of selection? Homework.

Heredity and variability
conservative and
ensures the preservation of signs
Variability
signs
leads to new

Certain or group variability (modification)

Visible
(definite) response
organism on the influence of the environment

Uncertain or Individual (hereditary) variability

Individual deviations
may be useful
neutral or harmful to
organism.
These changes are single
inadequate to influence
external factors appear
spontaneous and always inherited

1.
Lasting - insignificant
hereditary changes that
accumulate over generations
distinguish an individual from representatives of the same
kind.
2. The emergence of new forms as a result
sudden changes (mutational)

Varieties of hereditary variability (according to Ch. Darwin)

3.
Correlative or correlative -
change in one organ are
causes change in another (white
blue-eyed cats are deaf, pigeons have
feathered legs of the membrane between
fingers)
4. Combinative - variability from
crossbreeding, giving different combinations
signs

Variability - the property of living organisms to acquire new signs during life

non-hereditary
(phenotypic,
modification,
certain) variability
hereditary
9 genotypic,
indefinite)
variability
1. The phenotype changes under
the action of the environment
environment, genotype is not
changes
2. Not by inheritance
transmitted
3.Wear adaptive
and massive
4. Predictable and reversible
5. Limits are defined
reaction rate; inherited
1. The phenotype changes in
consequence of change
genotype
2. Transmitted by
inheritance
3. Wears random
character
4. Unpredictable
irreversible
5. Is the foundation
diversity of living
organisms and the main
cause of evolutionary
process (source of material
not the attribute itself, but the ability
express it in specific
conditions, i.e. inherited
reaction rate
for natural selection)

Types of variability

non-hereditary
hereditary
Meaning
for an individual
Raises or
lowers
viability,
productivity,
adaptation
Helpful Changes
lead to victory in
struggle for existence
harmful - to death
Meaning
for the look
Promotes
survival
New
populations, species in
result of the process
divergences
Role in
evolution
form
adaptation
(devices)
organisms to
conditions
environment
supplies material for
natural selection

The role of artificial selection

studying
the work of breeders, Ch. Darwin
studied in detail the methods of developing new
breeds and varieties.

Conclusions of Ch. Darwin

1.
Each variety or breed is bred from
one original form presented
wild look. Prerequisite - variability
organisms
2.
Breeding of new varieties and breeds is impossible
be done by improving conditions
the content of organisms, since there is no
direct relationship between the appearance
new signs and factors of external
environments

Conclusions of Ch. Darwin

3.
One of the conditions for obtaining a new
cultural form - sudden
the occurrence of changes in a single
individuals. But such cases are rare and
are the main selections.
4.New
varieties and breeds - the result
human activities, including
assessment of small changes in individuals,
selection of parental pairs, crossing,
selection and rejection

artificial selection

Creative
purposeful
human activity
for the launch of a new
varieties or breeds

All
whether individuals leave
offspring?
If not, what
factors keep
individuals with useful
symptoms and eliminate
everyone else?
Darwin turned to
breeding analysis
organisms.

Based
on the study of large
number of facts from the field of natural science
and crop production practices and
animal husbandry Ch. Darwin comes to
conclusion about the existence in nature
desire to reproduce
view in geometric progression.
This rule knows no exceptions in
animal or plant kingdom.
Potentially each species is capable of
produce and produce much more
individuals than survives them to adulthood
states.
Young individuals are always more than
adults.

C. Darwin studied the fertility of an elephant

Elephant
lives 100 years
During the life of an elephant, no more than 6 are born
cubs
Offspring from one pair of elephants for 750 years
will be
19
million individuals

herring

1 individual
40 thousand eggs

sturgeon

1 individual
2 million eggs

poppy

1 plant
32 thousand seeds

Why is the number of adults of each plant and animal species more or less constant?

Having a fight
behind
Existence.

Struggle for existence

Each
a pair of organisms gives much
more offspring than they live to
adult state.
Most of those born
organisms die before reaching
puberty.
The causes of death are varied:
lack of food due to competition with
members of their own species
enemy attack, action
adverse physical factors
environments - drought, severe frosts,
high temperature, etc.

The struggle for existence

is the totality of all
relationships of individuals with each other
friend and inanimate
nature,
determined
the ability of this
individuals to survive and
leaving offspring.

Interspecies
Intraspecific
Fight against adverse
environmental conditions

Forms of struggle for existence

Form name
fight for
Existence
1. Interspecies
fight
2. Intraspecific
fight
3. Fighting
unfavorable
external
environments
The result of the struggle
Examples

Form name
fight for
Existence
The result of the struggle
Examples
1. Interspecies struggle
Use of one kind
others as food
resettlement in a new
territories
Repression of the pathetic
European bee
local Australian,
fight for food
species of the same genus - gray
and black rats
predation by predators
2. Intraspecific
fight
Conservation of the population and
species at the expense of the death of the weak.
victory over
viable
occupying the same
ecological niche
Competition between
predators of one
populations for prey,
intraspecific
cannibalism - destruction
young animals with excess
population size,
struggle for dominance in the pack
3. Fighting
unfavorable
external
environments
Survival in extreme or
changed conditions
fittest
In winter, animals change
color, coat density,
fall into hibernation

1.
2.
3.
4.
Rotation of crops (crop rotation)
Biological methods of dealing with
pests (use of trichograms,
equestrians, egg-eaters, attraction of birds)
Use in forest plantations of mycorrhizal
fungi that enter into symbiosis with
roots of higher plants and improve
soil nutrition of higher plants
In fish farming - the use of low-value
herbivorous breeds to protect ponds from
overgrowth

Human use of various forms of struggle for existence

5. In hunting management - the use of predators
like orderlies who destroy the sick and
weakened animals valuable for the economy
6. Use of phytoncides and antibiotics
to destroy or restrict competition
or as drugs
7. The use of various agrotechnical
techniques (picking, hilling, pinching,
watering, fertilizing, sowing seeds in
greenhouses or growing in greenhouses).

Natural selection as the driving force of evolution

What kind
individuals within the same species can
survive in a constant struggle for
Existence?
Ch. Darwin when comparing facts
struggle for existence and universal
variability of signs and properties, came
to the conclusion about the inevitability in nature
selective extermination of some individuals
and the reproduction of others
natural selection.

Natural selection

This is
the process of preserving
individuals at the expense of the death of others.

Indicator for
comparisons
Evolution
cultural forms
(artificial
selection)
Evolution
natural forms
(natural
selection)
Material for
selection
Individual
Individual
heredity (in hereditary
including sharp
variability (in
evasion)
mostly
minor
evasion)
selection factor
Human
Struggle for
existence on
background factors
living and non-living
nature

Comparison of artificial and natural selection

Indicator for
comparisons
Evolution
cultural forms
(artificial
selection)
Evolution
natural forms
(natural
selection)
Nature of action
selection
Accumulation of changes in
successive generations
Action speed
selection
Acts fast
(methodical
selection)
Active
slowly,
gradually
(evolution)
Selection Forms
Conscious,
unconscious
Moving,
stabilizing
Selection result
Creation of breeds and
varieties (forms
useful to man)
Species formation
and larger
taxa
(adaptations to
environment)

fixtures

inevitable
selection result
turned out to be the occurrence
devices and on this basis -
taxonomic and ecological
diversity.
Example: there are membranes between
fingers of waterfowl, but there are
and in mountain geese and the frigatebird. At the sparrow
dipper has no membranes, but it is fine
dives and swims.
Darwin explained this with time.

Thus, adaptations are relative.

This
feature Darwin called
relative
organic
expediency, i.e.
adaptation of organisms to the environment
habitat is relative and is losing
its value when conditions change
existence.

1.
Within each species there is
a huge amount of individual
hereditary variation in
various signs. This variability
always exists: there are no two
identical individuals throughout the population
signs.
2. All living organisms have
ability to increase

The main provisions of the theory of Ch. Darwin

3.
Life resources are limited
therefore, there is a struggle between individuals
for existence. In the midst of this struggle
those individuals survive and give offspring
which are most suited to
given conditions.
4.Selective survival and
reproduction of the fittest
individuals is called natural selection.
Natural selection taking place within
populations, gradually leading to
divergence of signs and eventually
eventually to visualization.

The main works of Ch. Darwin

1859
year - "The Origin of Species by
natural selection or conservation
favorable forms in the struggle for
a life"
1868 - "Change in Domestic Animals
and cultivated plants"
1871 - "The Descent of Man and
sexual selection"

"Development of Darwin's theory" - Compose a syncwine about K. Linnaeus, J.B. Lamarck C. Darwin. February 12, 1809 1831-1839 trip around the world. Scientific and socio-economic prerequisites for the emergence of Ch.Darwin's theory. Choose the correct answer: option 1 - Zh.B. Lamarck option 2 - K. Linnaeus. The main stages in the development of scientists' views on the question of Evolution.

"Darwin's theory" - Characteristics of artificial and natural selection. Forms of variability (according to Darwin). The results of evolution. Causes of evolution: the struggle for existence and natural selection. Certain, group, non-hereditary (modern - modification). Caused by the influence of the external environment. For evolution, only hereditary (indeterminate) variability matters.

"Basic provisions of Darwin's theory" - Theme of the lesson: "Basic provisions of Charles Darwin's theory of the evolution of the organic world." The purpose of the lesson: To consider the theory of evolution of Charles Darwin as a holistic teaching; to form an idea of ​​the main provisions of the evolutionary teachings of Charles Darwin.

"Charles Darwin" - Captain Robert Fitzroy. Return. Edinburgh student cards of Ch. Darwin. In recent years, he suffered from mental illness. Darwin's drawing of the geological structure of the Andes. Charles Darwin's matriculation record at the University of Cambridge. Darwin's house in Shrewsbury. On December 18, the island of Tierra del Fuego appeared on the horizon.

"Biology Darwin" - House of Dr. Robert Darwin, where C. Darwin was born. Darwin's handwritten diary. On the wall there is a small bas-relief with the image of Darwin and the inscription: The presentation was prepared by: Danilchenko O.V., a biology teacher of the highest qualification category of the Donetsk School No. 97. The Cambridge period of life 1828-1831. Stages of life.

"The Life of Charles Darwin" - The journey lasted nearly five years. The marriage ceremony was held in the traditions of the Anglican Church and in accordance with Unitarian traditions. C. Darwin's mother Susanna Darwin. Charles Darwin (1809-1882). WHEN AND WHERE WAS CHARLES DARWIN BORN? Cambridge. Many of the children and grandchildren themselves have achieved significant success.

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