Genetic Diversity

Genetic diversity, species diversity, and ecological diversity are the three levels of biodiversity. Genetic architecture is unique from individual to individual and expressed by hereditary-material DNA. A population is equipped to withstand stress from environmental factors due to a wide range of gene sets. One of the driving forces behind evolution is genetic diversity. It also serves as the chief criterion for natural selection.

Genetic Diversity

Image: Genetic Diversity

Table of Contents:

What is Genetic Diversity?
Significance of Genetic Diversity
Components of Genetic Diversity
Examples of Genetic Diversity
Conservation of Genetic Diversity

What is Genetic Diversity?

Recombination of genetic material in the inheritance process leads to genetic diversity. It evolves with space and time. Sexual reproduction is essential for preserving genetic diversity due to generating unique offspring by fusing the parents' genes. Mutation of genes, flow, and genetic drift also generate genetic diversity.

Definition: Genetic diversity is characterised by the existence of genetic variability within species.

Significance of Genetic Diversity

Genetic diversity plays a crucial role in ecosystems. They include the following:

Natural selection and the survival of the fittest are governed by environmental alteration due to natural or human inventions. Genetic diversity leads to the vulnerable variety dying, and the one who adapts to changes survives.
Genetic diversity aids in a person's ability to adapt to stress, unfavourable environmental conditions, diseases, and distinct physical characteristics.
The diversity in various genes that may resist diseases, pests or other conditions can be maintained. Genetic diversity is an essential factor for a healthy population.
By cross-breeding numerous genetic variants, generating new plant species with desired traits like increased stress tolerance and disease resistance is possible.
The frequency of unwanted hereditary characteristics is decreased by genetic diversity.
Genetic diversity guarantees that certain species survivors are present in the ecosystem.

Components of Genetic Diversity

Genetic diversity is impacted by a wide range of evolutionary processes that involves genetic drift, mutation, natural selection and gene flow. However, a whole new set of alleles can only be produced through mutations.

1. Genetic Drift

Genetic drift is a random fluctuation in a population’s frequency of a given allele from generation to generation due to chance sampling events that are less prominent in larger populations.

2. Mutation

Modifications or alterations in the nucleotide sequence of DNA are called mutation. Thus, the alteration or replacement of genes and chromosomes is the chief cause of mutation. A population’s genetic structure can alter because of the new alleles created by mutations.

3. Natural Selection

Natural selection happens when individuals who can adapt to environmental alterations reproduce more often, changing the population's gene pool.

4. Gene Flow

Gene flow or gene migration is the migration of alleles among a population. The process involves allele transportation from one population to the other, causing the production of future generations with that allele. However, they possess distinct frequencies for this allele.

Examples of Genetic Diversity

There are numerous examples of genetic diversity. Some include-

The essential qualities can be achieved when dogs are selectively bred.
Several forms of rose, wheat, rice and flowers.
More than 1000 species of mangoes in India.
50,000 distinct types of rice.
A distinct variety of Rauvolfia, a medicinal plant, exists in Himalayan ranges, each possessing a distinct volume of chemical reserpine.

Conservation of Genetic Diversity

Practices like natural habitat destruction or selective harvesting lead to loss of diversity. It is essential to conserve diversity for human health and prevent species from being extinct. A lost species may hold a wide range of benefits to the ecosystem.

Growing genetically diverse and disease-resistant species is feasible by preserving diversity in conditions where the whole crop is deteriorated by drought or a sudden outbreak of disease. There are many methods to conserve biodiversity. They include

1. In situ Conservation

As it is difficult to conserve biodiversity, specific hotspots are identified and preserved to protect species that are endemic to a particular ecosystem and are in danger of extinction or endangered. For example, wildlife sanctuaries and national parks.

2. Ex-situ Conservation

Endangered plants and animals are removed from their natural ecosystem and conserved in specific habitats to offer special care and security. For example, botanical gardens, safaris and zoos. Also, it includes the following:

Cryopreservation: Using the cryopreservation technique, gametes and threatened species are preserved in viable and fertile conditions for longer.
Tissue Culture: Propagation of plants can be carried out, and in-vitro fertilisation of plants can be done through tissue culture.
Genomic Library: A recent advancement in science that conserves genetic diversity is aided through the Genomic Library.

Practice Problems

Q1. Gene recombination during the process of inheritance can result in

a. Genetic diversity
b. In situ conservation
c. Ex-situ conservation
d. Gene flow

Ans. a. Genetic diversity

Genetic diversity occurs due to the recombination of genes in the inheritance process.

Q2. Genetic diversity alters with

a. Space
b. Time
c. Mutation
d. Both a and b

Ans. d. Both a and b

Genetic diversity is influenced by space and time, as they play a critical role in shaping it.

Q3. In situ conservation include

a. Animal reservoirs
b. National parks
c. Wildlife sanctuaries
d. All of the above

Ans. d. All of the above

In situ conservation includes wildlife sanctuaries, animal reservoirs and national parks.

Q4. Ex situ conservation include

a. Wildlife sanctuaries
b. National parks
c. Animal reservoirs
d. None of the above

Ans. d. None of the above

These come under in-situ conservation. At the same time, ex-situ conservation includes botanical gardens, zoological gardens and wildlife safaris.

Frequently Asked Questions

Q1. What is an ecosystem?
Answer: A geographical area that involves animals, plants and other organisms along with the abiotic pools with which they interact.

Q2. Who is the father of genetics?
Answer: Gregor Mendel is popularly known as the father of modern genetics, owing to the discovery of inheritance principles.

Q3. How does population size influence genetic diversity?
Answer: Certain populations lose genetic diversity more frequently than larger populations because of genetic drift or stochastic sampling error.