Unit I
1.1. Biodiversity: Concepts,
1.1.1. Definition.
1.1.2. Values of biodiversity: Consumptive use and Productive use ; Social,
Ethical, Aesthetic, Option & Environment service values,
1.2. Genetic diversity:
1.2.1. Nature and origin of genetic variations;
1.2.2. Measurement of genetic Diversity.
1.3. Species diversity:
1.3.1. History and origin of species diversity;
1.3.2. Species diversity indices ;
1.3.3. Measures of diversity - Alpha, Beta & Gamma diversity.
1.4. Ecosystem diversity:
1.4.1. Classification and nature of ecosystems (in brief);
1.4.2. Ecosystem diversity of India (in brief),
1.4.3. Agro- biodiversity:
1.4.4. Origin and evolution of cultivated species diversity;
1.4.5. Vavilovian centers;
1.4.6. Diversity in domesticated animal species.
8
1.1. Biodiversity-Concepts
The term biodiversity was coined as a contraction of biological diversity by E.O.
Wilson in 1985. Biodiversity may be defined as the variety and variability of
living organisms and the ecological complexes in which they exist. In other
words, biodiversity is the occurrence of different types of ecosystems, different
species of organisms with the whole range of their variants and genes adapted
to different climates, environments along with their interactions and
processes. Biodiversity includes the genetic variability (for which different
varieties of spices have appeared in the course of evolution) and diversity of
life forms such as plants, animal microbes, etc. living in a wide range of
ecosystems.
-1-
,• Types of Biodiversity :
There are three interrelated hierarchical levels of biodiversity namely, genetic
diversity, species diversity and community or ecosystem diversity.
i. Genetic diversity: It describes the variation in the number and types of genes
as well as chromosomes present in different species. The magnitude of variation
in genes of a species increases with increase in size and environmental
parameters of the habitat.
The genetic aviation arises by gene and chromosome mutation in individuals
and in sexually reproducing organisms and it is spread in the population by
recombination of genetic materials during cell division after sexual
reproduction. Genetic diversity has the following importance:
(i) It helps in speciation or evolution of new species;
(ii) It is useful in adaptation to changes in environmental conditions:
(iii) It is important for agricultural productivity and development.
ii. Species diversity: It describes the variety in the number and richness of the
spices with in a region. The species richness may be defined as the number of
species per unit area. The richness of a species tells about the extent of
biodiversity of a site and provides a means for comparing different sites. The
species richness depends largely on climatic conditions.
The number of individuals of different species with in a region represents
species evenness or species equitability. The product species richness and species
evenness give species diversity of a region. When a species is confined entirely to
a particular area, it is termed as endemic species.
iii. Ecosystem diversity: It describes the assemblage and Interaction of spices
living together and the physical environment a given area It relates varieties of
habitats, biotic communities ecological processes in biosphere It also tells about
the diversity within the ecosystem. It is referred as Land escape diversity
because it includes placement and size of various ecosystems. For example, the
landscapes like grass lands, deserts, mountains etc. show ecosystem diversity.
The ecosystem diversity is due to diversity of niches, trophic levels and
ecological processes like nutrient cycling, food webs, energy flow, role of
dominant species and various related biotic interactions. Such type of diversity
can generate more productive and stable ecosystems or communities capable of
tolerating various types of stresses e.g. drought, flood etc.
-2-
,• Importance of Biodiversity:
The living organisms on earth are of great diversity, living in diverse habitats
and possessing diverse qualities and are vital to human existence providing
food, shelter, clothing’s, medicines etc. The biodiversity has the following
importance’s?
I. Productive values: Biodiversity produces 9K number of products harvested
from nature and sold in commercial markets. Indirectly it provides economic
benefits to people which include water quality soil protection, equalisation of
climate, environmental monitoring, scientific research, recreation etc.
2. Consumptive value: The consumptive value can be assigned to goods such as
fuel woods, leaves, forest products etc. which may be consumed locally and do
not figure national and international market.
3. Social value: The loss of biodiversity directly influences the social life of the
country possibly through influencing ecosystem functions (energy flow and
biogeochemical cycle). This be easily understood by observing detrimental
effects of global warming and acid rain which cause an unfavorable alteration
in logical processes.
4. Aesthetic value: Aesthetic values such as refreshing fragrance of the flowers,
taste of berries, softness of mossed, melodious songs of birds, etc. compel the
human beings to preserve them. The earth s natural beauty with its colour and
ages, thick forest, and graceful beasts has inspired the human beings from
their date of birth to take necessary steps for its maintenance. Similarly
botanical and zoological gardens are the means of biodiversity conservation
and are of aesthetic values.
5. Legal values: Since earth is homeland of all living organisms, all have equal
right to coexist on the surface of earth with all benefits. Unless some legal
value is attached to biodiversity, it will not be possible to protect the rapid
extinction of species.
-3-
, 6. Ethical value: Biodiversity must be seen in the light of holding ethical value.
Since man is the most intelligent amongst the living organisms. It should be
prime responsibility and moral obligation of man to preserve and conserve
other organisms which will directly or indirectly favour the existence of the
man.
7. Ecological value: Biodiversity holds great ecological value because it is
indispensable to maintain the ecological balance. Any disturbance in the
delicately fabricated ecological balance maintained by different organisms,
will lead to severe problems, which may threaten the survival of human beings.
8. Economic value Biodiversity has great economic value because economic
development depends upon efficient and economic management of biotic
resources. In the day to day life, human beings are maintaining their lifestyle
at the sacrifice of surrounding species which come from diversity of plants and
animals struggling for their existence. So, it is highly essential for the human
beings to take care of their surrounding species and make optimum use of their
service, for better economic development. Thus, it is rightly told, survival of the
man depends upon the survival of the biosphere.
• Uses of Biodiversity:
Biodiversity has the following uses for the development humanity:
(i) It provides food of all types.
(ii) It provides fibers, sources for the preparation of clothes.
(iii) It provides different types of oil seeds for the preparation of oils.
(iv) It provides new varieties of rice, potato etc. through the process of
hybridization.
(v) It provides different drugs and medicines which are based on
different plant products
(vi) It is very essential for natural pest control, maintenance of
population of various species, pollination by insects and birds,
nutrient cycling, conservation and purification of water, formation
of soil etc. All these services together are valued 16.54 trillion dollars
per year.
-4-
1.1. Biodiversity: Concepts,
1.1.1. Definition.
1.1.2. Values of biodiversity: Consumptive use and Productive use ; Social,
Ethical, Aesthetic, Option & Environment service values,
1.2. Genetic diversity:
1.2.1. Nature and origin of genetic variations;
1.2.2. Measurement of genetic Diversity.
1.3. Species diversity:
1.3.1. History and origin of species diversity;
1.3.2. Species diversity indices ;
1.3.3. Measures of diversity - Alpha, Beta & Gamma diversity.
1.4. Ecosystem diversity:
1.4.1. Classification and nature of ecosystems (in brief);
1.4.2. Ecosystem diversity of India (in brief),
1.4.3. Agro- biodiversity:
1.4.4. Origin and evolution of cultivated species diversity;
1.4.5. Vavilovian centers;
1.4.6. Diversity in domesticated animal species.
8
1.1. Biodiversity-Concepts
The term biodiversity was coined as a contraction of biological diversity by E.O.
Wilson in 1985. Biodiversity may be defined as the variety and variability of
living organisms and the ecological complexes in which they exist. In other
words, biodiversity is the occurrence of different types of ecosystems, different
species of organisms with the whole range of their variants and genes adapted
to different climates, environments along with their interactions and
processes. Biodiversity includes the genetic variability (for which different
varieties of spices have appeared in the course of evolution) and diversity of
life forms such as plants, animal microbes, etc. living in a wide range of
ecosystems.
-1-
,• Types of Biodiversity :
There are three interrelated hierarchical levels of biodiversity namely, genetic
diversity, species diversity and community or ecosystem diversity.
i. Genetic diversity: It describes the variation in the number and types of genes
as well as chromosomes present in different species. The magnitude of variation
in genes of a species increases with increase in size and environmental
parameters of the habitat.
The genetic aviation arises by gene and chromosome mutation in individuals
and in sexually reproducing organisms and it is spread in the population by
recombination of genetic materials during cell division after sexual
reproduction. Genetic diversity has the following importance:
(i) It helps in speciation or evolution of new species;
(ii) It is useful in adaptation to changes in environmental conditions:
(iii) It is important for agricultural productivity and development.
ii. Species diversity: It describes the variety in the number and richness of the
spices with in a region. The species richness may be defined as the number of
species per unit area. The richness of a species tells about the extent of
biodiversity of a site and provides a means for comparing different sites. The
species richness depends largely on climatic conditions.
The number of individuals of different species with in a region represents
species evenness or species equitability. The product species richness and species
evenness give species diversity of a region. When a species is confined entirely to
a particular area, it is termed as endemic species.
iii. Ecosystem diversity: It describes the assemblage and Interaction of spices
living together and the physical environment a given area It relates varieties of
habitats, biotic communities ecological processes in biosphere It also tells about
the diversity within the ecosystem. It is referred as Land escape diversity
because it includes placement and size of various ecosystems. For example, the
landscapes like grass lands, deserts, mountains etc. show ecosystem diversity.
The ecosystem diversity is due to diversity of niches, trophic levels and
ecological processes like nutrient cycling, food webs, energy flow, role of
dominant species and various related biotic interactions. Such type of diversity
can generate more productive and stable ecosystems or communities capable of
tolerating various types of stresses e.g. drought, flood etc.
-2-
,• Importance of Biodiversity:
The living organisms on earth are of great diversity, living in diverse habitats
and possessing diverse qualities and are vital to human existence providing
food, shelter, clothing’s, medicines etc. The biodiversity has the following
importance’s?
I. Productive values: Biodiversity produces 9K number of products harvested
from nature and sold in commercial markets. Indirectly it provides economic
benefits to people which include water quality soil protection, equalisation of
climate, environmental monitoring, scientific research, recreation etc.
2. Consumptive value: The consumptive value can be assigned to goods such as
fuel woods, leaves, forest products etc. which may be consumed locally and do
not figure national and international market.
3. Social value: The loss of biodiversity directly influences the social life of the
country possibly through influencing ecosystem functions (energy flow and
biogeochemical cycle). This be easily understood by observing detrimental
effects of global warming and acid rain which cause an unfavorable alteration
in logical processes.
4. Aesthetic value: Aesthetic values such as refreshing fragrance of the flowers,
taste of berries, softness of mossed, melodious songs of birds, etc. compel the
human beings to preserve them. The earth s natural beauty with its colour and
ages, thick forest, and graceful beasts has inspired the human beings from
their date of birth to take necessary steps for its maintenance. Similarly
botanical and zoological gardens are the means of biodiversity conservation
and are of aesthetic values.
5. Legal values: Since earth is homeland of all living organisms, all have equal
right to coexist on the surface of earth with all benefits. Unless some legal
value is attached to biodiversity, it will not be possible to protect the rapid
extinction of species.
-3-
, 6. Ethical value: Biodiversity must be seen in the light of holding ethical value.
Since man is the most intelligent amongst the living organisms. It should be
prime responsibility and moral obligation of man to preserve and conserve
other organisms which will directly or indirectly favour the existence of the
man.
7. Ecological value: Biodiversity holds great ecological value because it is
indispensable to maintain the ecological balance. Any disturbance in the
delicately fabricated ecological balance maintained by different organisms,
will lead to severe problems, which may threaten the survival of human beings.
8. Economic value Biodiversity has great economic value because economic
development depends upon efficient and economic management of biotic
resources. In the day to day life, human beings are maintaining their lifestyle
at the sacrifice of surrounding species which come from diversity of plants and
animals struggling for their existence. So, it is highly essential for the human
beings to take care of their surrounding species and make optimum use of their
service, for better economic development. Thus, it is rightly told, survival of the
man depends upon the survival of the biosphere.
• Uses of Biodiversity:
Biodiversity has the following uses for the development humanity:
(i) It provides food of all types.
(ii) It provides fibers, sources for the preparation of clothes.
(iii) It provides different types of oil seeds for the preparation of oils.
(iv) It provides new varieties of rice, potato etc. through the process of
hybridization.
(v) It provides different drugs and medicines which are based on
different plant products
(vi) It is very essential for natural pest control, maintenance of
population of various species, pollination by insects and birds,
nutrient cycling, conservation and purification of water, formation
of soil etc. All these services together are valued 16.54 trillion dollars
per year.
-4-
