Introduction to Biodiversity
Biodiversity is a term used to describe the vast array of life forms and their various relationships with one another.
Evolution of concept of Biodiversity
- 1980 – Thomas Lovejoy introduced the term biological diversity to the scientific community in a book.
- 1985- The term biodiversity was given by Walter G. Rosen (1985) as a compound word for the term 'Biological Diversity.
- 1988- Biodiversity is the term popularised and conceptualized by the sociobiologist Edward Wilson in 1988.
Levels of biological diversity
1. Genetic diversity
- Genetic diversity refers to the variation in terms of genetic makeup within species, which is transferred across generations.
- This genetic variability is essential for a healthy breeding population of a species.
- If the number of breeding individuals is reduced, the dissimilarity of genetic makeup is reduced and in-breeding occur.
- The variety of wild species available in nature constitutes the "gene pool" that has been used to create our cultivated crops and domesticated animals over several millennia.
- Gene is the functional unit of heredity; the part of the DNA molecule which codes for one polypeptide and so for some characteristic feature
2. Species diversity-
- Species diversity refers to the variety of species within a given habitat or region.
- The Western Ghats exhibit a greater diversity of amphibian species compared to the Eastern Ghats.
- A value of 'zero' for species diversity would indicate infinite diversity, while a value of 'one' would represent the presence of only one species.
Components of Species diversity
A. Species richness or variety-
- It means the total number of species per unit area and also known as species density.
B. Relative abundance or species evenness -
- It represents the relative proportion of each species in an area.
- It is used to compare species in two individual communities.
- Simpson’s Index is index related to both species evenness and species richness.
Species diversity can also be classified depending upon area or spatial consideration
1. Alpha-(α)-
- It is the diversity of species within a community.
2. Beta-(β)-
- This diversity is the measure of variation in species diversity between two or more adjacent communities
3. Gamma-(γ)-
- A landscape or geographic region's diversity is measured by the total number of species it contains, according to the concept of diversity.
C. Ecological diversity
- It studies variation in the biological communities in which species Jive, exist and interact.
- Earth is home to a diverse range of ecosystems, each with its unique set of interconnected species that are influenced by the specific conditions of their habitat.
Important Terms related to Biodiversity
1. Umbrella species-
- Umbrella species refer to those that are crucial to maintaining a healthy ecosystem.
- They serve as indicators of the overall health and stability of an ecosystem.
- An example of an umbrella species is the tiger, which is essential to forest ecosystems.
- The presence of tigers as top predators ensures the balance of herbivore and producer populations.
- Protecting umbrella species benefits entire ecosystems and the numerous other species within them.
2. Keystone species-
- Keystone species are organisms that exert a significant influence on a particular ecosystem in proportion to their population size.
- Absence of keystone species would result in collapse of ecosystem.
- For example, elephants are considered as keystone species. Elephants require large area to move around and also has requires high amount of food. Presence of elephants in forest indicate that ecosystem is healthy and in good condition.
3. Flagship species
- Flagship species are those that hold cultural, emotional, and ecological significance within a society and are highlighted by the government to improve conservation efforts.
- In India, for example, the tiger is recognized as the national animal.
- These species are chosen for their ability to attract public attention and support for conservation efforts.
- Flagship species can serve as ambassadors for the conservation of the ecosystem and the other species that live within it.
- The protection and preservation of flagship species can help promote conservation practices and educate the public about the importance of biodiversity.
4. Indicator species-
- These species indicate the overall health of an ecosystem because they are sensitive to small change in ecosystem like temperature, pollution etc.
- For example, greasewood indicates saline soil; mosses often indicate acid soil. Tubifex worms indicate oxygen-poor and stagnant water unfit to drink.
5. Endemic species-
- Endemic species refer to those that are confined to a specific geographical region and do not exist naturally in any other part of the globe.
One Liner Questions and Answers on Biodiversity.
Who introduced the term "biological diversity" to the scientific community in a book in 1980?
Thomas Lovejoy.
Who coined the term "biodiversity" in 1985?
Walter G. Rosen.
Who popularized and conceptualized the term "biodiversity" in 1988?
Edward Wilson.
What is genetic diversity?
It refers to the variation in terms of genetic makeup within species, which is transferred across generations.
Why is genetic diversity important?
Genetic variability is essential for a healthy breeding population of a species.
How can reduction in the number of breeding individuals affect genetic diversity?
If the number of breeding individuals is reduced, the dissimilarity of genetic makeup is reduced, and inbreeding occurs.
What is the "gene pool" in biodiversity?
The variety of wild species available in nature constitutes the "gene pool" that has been used to create our cultivated crops and domesticated animals over several millennia.
What is species diversity?
It refers to the variety of species within a given habitat or region.
What is species richness or variety in species diversity?
It means the total number of species per unit area and also known as species density.
What is relative abundance or species evenness in species diversity?
It represents the relative proportion of each species in an area and is used to compare species in two individual communities.
What is Simpson's Index in species diversity?
It is an index related to both species evenness and species richness.
How can species diversity be classified depending upon area or spatial consideration?
Alpha (α), Beta (β), and Gamma (γ).
What is ecological diversity?
It studies variation in the biological communities in which species live, exist, and interact.
What are umbrella species in biodiversity?
Umbrella species refer to those that are crucial to maintaining a healthy ecosystem and serve as indicators of the overall health and stability of an ecosystem.
What are endemic species in biodiversity?
Endemic species refer to those that are confined to a specific geographical region and do not exist naturally in any other part of the globe.