Biodiversity and its types pdf
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- Biodiversity: Concept, Types and Other Details (With Diagram)
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Oh, the beauty of a forest! The pleasure of walking through it, enjoying the smells of the flowers and the wild; watching the insects flitting about and listening to the birds chirp - how we all love it and wish to return to it again and again. It is this biodiversity that we have to protect and take care of in order to enjoy the joy of it all. But what is biodiversity? Biodiversity is the variety and differences among living organisms from all sources, including terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are a part.
This includes genetic diversity within and between species and of ecosystems. Thus, in essence, biodiversity represents all life. The forest cover in these areas is very dense and diverse and of pristine beauty, and incredible biodiversity. The figures are 49, plant species representing The sacred groves of India are some of the areas in the country where the richness of biodiversity has been well preserved.
The Thar desert and the Himalayas are two regions rich in biodiversity in India. There are 89 national parks and wildlife sanctuaries in the country, the Chilika Lake being one of them.
This lake is also an important wetland area. Learn more through map on biodiversity in India. Over the last century, a great deal of damage has been done to the biodiversity existing on the earth. Increasing human population, increasing consumption levels, and decreasing efficiency of use of our resources are some of the causes that have led to overexploitation and manipulation of ecosystems. Trade in wildlife, such as rhino horn, has led to the extinction of species. Consequences of biodiversity loss can be great as any disturbance to one species gives rise to imbalance in others.
In this the exotic species have a role to play. To prevent such loss, the Government of India is setting up biosphere reserves in different parts of the country. These are multipurpose protected areas to preserve the genetic diversity in different ecosystems. A number of NGOs are being involved in the programme to create awareness. But legal protection is provided only to national parks and sanctuaries, which cover about 4.
Definitions The most straightforward definition is "variation of life at all levels of biological organization". A third definition that is often used by ecologists is the "totality of genes, species, and ecosystems of a region". This is, in fact, the closest thing to a single legally accepted definition of biodiversity, since it is the definition adopted by the United Nations Convention on Biological Diversity. If the gene is the fundamental unit of natural selection, according to E.
Wilson, the real biodiversity is genetic diversity. For geneticists, biodiversity is the diversity of genes and organisms. They study processes such as mutations, gene exchanges, and genome dynamics that occur at the DNA level and generate evolution. It is distinguished from genetic variability, which describes the tendency of genetic characteristics to vary.
The academic field of population genetics includes several hypotheses regarding genetic diversity. The neutral theory of evolution proposes that diversity is the result of the accumulation of neutral substitutions. Diversifying selection is the hypothesis that two subpopulations of a species live in different environments that select for different alleles at a particular locus. This may occur, for instance, if a species has a large range relative to the mobility of individuals within it.
Frequency-dependent selection is the hypothesis that as alleles become more common, they become less fit. This is often invoked in host-pathogen interactions, where a high frequency of a defensive allele among the host means that it is more likely that a pathogen will spread if it is able to overcome that allele.
Importance Of Genetic Diversity There are many different ways to measure genetic diversity. The modern causes for the loss of animal genetic diversity have also been studied and identified. A September 14, study conducted by the National Science Foundation found that genetic diversity and biodiversity are dependent upon each other -- that diversity within a species is necessary to maintain diversity among species, and vice versa.
According to the lead researcher in the study, Dr. Richard Lankauof, "If any one type is removed from the system, the cycle can break down, and the community becomes dominated by a single species. A species that has a large degree of genetic diversity among its individuals will have more variations from which to choose the most fitting allele. Species that have very little genetic variation are at a great risk. With very little gene variation within the species, healthy reproduction becomes increasingly difficult, and offspring often deal with similar problems to those of inbreeding.
Agricultural Relevance When humans initially started farming, they used selective breeding to pass on desirable traits of the crops while omitting the undesirable ones. Selective breeding leads to monocultures: entire farms of nearly genetically identical plants. Little to no genetic diversity makes crops extremely susceptible to widespread disease. Bacteria morph and change constantly.
When a disease causing bacteria changes to attack a specific genetic variation, it can easily wipe out vast quantities of the species. If the genetic variation that the bacterium is best at attacking happens to be that which humans have selectively bred to use for harvest, the entire crop will be wiped out. Since new potato plants do not come as a result of reproduction but rather from pieces of the parent plant, no genetic diversity is developed, and the entire crop is essentially a clone of one potato, it is especially susceptible to an epidemic.
This mold destroyed the vast majority of the potato crop, and left thousands of people to starve to death. In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring.
While in many cases this definition is adequate, more precise or differing measures are often used, such as based on similarity of DNA or morphology. Presence of specific locally adapted traits may further subdivide species into subspecies. The commonly used names for plant and animal taxa sometimes correspond to species: for example, "lion," "walrus," and "Camphor tree" — each refers to a species. In other cases common names do not: for example, "deer" refers to a family of 34 species, including Eld's Deer, Red Deer and Elk Wapiti.
The last two species were once considered a single species, illustrating how species boundaries may change with increased scientific knowledge.
Each species is placed within a single genus. This is a hypothesis that the species is more closely related to other species within its genus than to species of other genera. All species are given a binomial name consisting of the generic name and specific name or specific epithet. For example, Pinus palustris commonly known as the Longleaf Pine. The taxonomic ranks are life, domain, kingdom, phylum, class, order, family, genus, and species.
A usable definition of the word "species" and reliable methods of identifying particular species are essential for stating and testing biological theories and for measuring biodiversity. Traditionally, multiple examples of a proposed species must be studied for unifying characters before it can be regarded as a species. Extinct species known only from fossils are generally difficult to give precise taxonomic rankings to. Binomial convention for naming species In scientific classification, a species is assigned a two-part name, treated as Latin, although roots from any language can be used as well as names of locales or individuals.
The genus is listed first with its leading letter capitalized , followed by a second term: for example, gray wolves belong to the species Canis lupus, coyotes to Canis latrans, golden jackals to Canis aureus, etc. The name of the species is the whole binomial, not just the second term which may be called specific name for animals. The binomial naming convention that is used, later formalized in the biological codes of nomenclature, was first used by Leonhart Fuchs and introduced as the standard by Carolus Linnaeus in his classical work Systema Naturae 10th edition.
As a result, it is sometimes called the "binomial nomenclature. Abbreviation Books and articles sometimes intentionally do not identify species fully and use the abbreviation "sp. This is particularly common in paleontology. If scientists mean that something applies to all species within a genus, they use the genus name without the specific epithet. In books and articles that use the genus and species names are usually printed in italics.
If using "sp. Difficulty of defining "species" and identifying particular species It is surprisingly difficult to define the word "species" in a way that applies to all naturally occurring organisms, and the debate among biologists about how to define "species" and how to identify actual species is called the species problem. Most textbooks follow Ernst Mayr's definition of a species as all the individual organisms of a natural population that generally interbreed at maturity in the wild and whose interbreeding produces fertile offspring.
For example, mules and hinnies have rarely produced further offspring only one documented case for hinnies, and seven for mules when mated with a creature of the same type a mule with a mule, or a hinny with a hinny.
So it does not work for asexually reproducing single-celled organisms and for the relatively few parthenogenetic multi-celled organisms. The term "phylotype" is often applied to such organisms. Some hybrids, e. Usually in such hybrids the males are sterile, so one could improve the basic textbook definition by changing " Horizontal gene transfer makes it even more difficult to define the word "species".
There is strong evidence of horizontal gene transfer between very dissimilar groups of procaryotes, and possibly between dissimilar groups of single-celled eucaryotes; and Williamson argues that there is evidence for it in some crustaceans and echinoderms. All definitions of the word "species" assume that an organism gets all its genes from one or two parents which are very like that organism, but horizontal gene transfer makes that assumption false.
Definitions of Species The question of how best to define "species" is one that has occupied biologists for centuries, and the debate itself has become known as the species problem. The modern theory of evolution depends on a fundamental redefinition of "species. Darwin's theories shifted attention from uniformity to variation and from the general to the particular.
According to intellectual historian Louis Menand, Once our attention is redirected to the individual, we need another way of making generalizations. We are no longer interested in the conformity of an individual to an ideal type; we are now interested in the relation of an individual to the other individuals with which it interacts. To generalize about groups of interacting individuals, we need to drop the language of types and essences, which is prescriptive telling us what finches should be , and adopt the language of statistics and probability, which is predictive telling us what the average finch, under specified conditions, is likely to do.
Relations will be more important than categories; functions, which are variable, will be more important than purposes; transitions will be more important than boundaries; sequences will be more important than hierarchies. Practically, biologists define species as populations of organisms that have a high level of genetic similarity. This may reflect an adaptation to the same niche, and the transfer of genetic material from one individual to others, through a variety of possible means.
The exact level of similarity used in such a definition is arbitrary, but this is the most common definition used for organisms that reproduce asexually, such as some plants and microorganisms. This lack of any clear species concept in microbiology has led to some authors arguing that the term "species" is not useful when studying bacterial evolution.
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The number and variety of organisms found within a specified geographic region. The variability among living organisms on the earth, including the variability within and between species and within and between ecosystems. Biological diversity — or biodiversity — is the term given to the variety of life on Earth. It is the variety within and between all species of plants, animals and micro-organisms and the ecosystems within which they live and interact. Biodiversity comprises all the millions of different species that live on our planet, as well as the genetic differences within species. It also refers to the multitude of different ecosystems in which species form unique communities, interacting with one another and the air, water and soil.
Biodiversity: Concept, Types and Other Details (With Diagram)
Biodiversity loss includes the extinction of species plant or animal worldwide, as well as the local reduction or loss of species in a certain habitat , resulting in a loss of biological diversity. Global extinction is being driven by human activities which overreach beyond the planetary boundaries as part of the Anthropocene and has so far been proven to be irreversible. Even though permanent global species loss is a more dramatic and tragic phenomenon than regional changes in species composition , even minor changes from a healthy stable state can have dramatic influence on the food web and the food chain insofar as reductions in only one species can adversely affect the entire chain coextinction , leading to an overall reduction in biodiversity , possible alternative stable states of an ecosystem notwithstanding.
Biological diversity. Biodiversity means variation of life on Earth, from variation of genes and other biomolecules to variation of species and ecosystems, variation in the biosphere, the relatively thin layer of life covering Earth. The concept of biodiversity becomes more accurate when we think of another major variation in nature, geological variation or geodiversity, that is, variation in rocks, minerals, soils, and landforms.
Oh, the beauty of a forest! The pleasure of walking through it, enjoying the smells of the flowers and the wild; watching the insects flitting about and listening to the birds chirp - how we all love it and wish to return to it again and again. It is this biodiversity that we have to protect and take care of in order to enjoy the joy of it all.
Biodiversity is the variety of life. It can be studied on many levels.