Genetic Diversity

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Introduction

Various plants and animals inhabit an ecosystem. This variety in the various life forms living in an ecosystem is called biodiversity. Furthermore, biodiversity has different levels, that are - species diversity, genetic diversity, and ecosystem diversity. The genetic make-up of every individual is different. And this is determined by the genes or heredity. Genes evolve over a period depending upon the environmental conditions and help individuals and communities survive the stressful conditions and reproduce to keep the species going. Thus, genetic diversity is a means by which population adapts to changing environments.

We will study more about genetic diversity and its aspects in this chapter.


What is Genetic Diversity?

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Genetic diversity indicates a greater number of genetically different individuals within the same species. It is the way by which a population of organisms survive the changing environments. More genetic variation suggests a greater number of individuals with a variety of alleles that help sustain the organisms in the changing environment. These individuals most often produce offspring with the same alleles. In a generation when such genetically evolved individuals succeed to survive, they also let the continuation of their species.


Some Attributes of Genetic Diversity:

  • It occurs as a result of gene recombination in the process of inheritance.

  • Genetic diversity changes with space and time.

  • One of the key aspects of genetic diversity in sexual reproduction because it produces unique offspring by a combination of parental genes.

  • Gene mutation, genetic drift, gene flow also lead to genetic diversity.

Significance of Genetic Diversity

Genetic diversity helps individuals of the species adapt to stressful environmental conditions. It gives the individuals the capacity and physical attributes to adapt to unfavourable environmental conditions, resistance to diseases, and so on.


Our environment goes through a series of changes because of human interventions and natural factors. The species have to adjust to this change to survive. Naturally, it gives rise to natural selection and goes by the theory of survival of the fittest. Which means, the individuals susceptible to the changing environment will perish and the ones with the capability to adapt will survive it. So genetic diversity produces a variety of individuals that can survive and continue the species.


It helps maintain different varieties of genes and healthy population with individuals resistant to a variety of stress like diseases, pests or other conditions.


It enables farmers to grow new varieties of plants by cross-breeding genetically different variants. This produces plants that have desirable traits like disease-resistant plants or plants that can withstand climatic stress. It also includes a plant that can survive with very less amount of water and so on.

Undesirable inherited traits can be avoided by making use of genetic diversity.


Genetic diversity ensures the continuity of species and that all the individuals of the species do not perish.


Examples of Genetic Diversity

  1. Different plant breeds are crossbred to get the desired trait in a particular plant.

  2. Humans have created dog breeds by selective breeding.

  3. Coyotes are naturally evolved generalist species adaptive to an array of environments.

  4. Varieties of plants like medicinal plants are obtained by interbreeding of plant species.

Conservation of Genetic Diversity

Genetic diversity gets hampered when genes are lost. These lost genes might have beneficial alleles and losing them may pose a threat to the survival of species. Therefore, the conservation of genetic diversity is important. It is a crucial measure to preserve human health and save plant and animals species from extinction.


Moreover, we may be able to grow a genetically diverse species to withstand the calamities of nature and diseases with the help of genetic diversity.


Methods to Conserve Genetic Diversity

In Situ Conservation - It is not possible to conserve whole of genetic biodiversity at once. Therefore, certain hotspots are recognized and conservation measures are implied to protect the endemic species whose survival is threatened at a particular habitat. Or, species at a higher risk of getting extinct are also conserved. These hotspots include wildlife sanctuaries, national parks, animal reserves, etc.


Ex Situ Conservation - In this type of conservation, endangered species of plants and animals are taken out from their habitat and are kept in a specially engineered setting that allows extra care and protection, takes away the chances of more animal killing by predation or poaching. This includes a zoo, botanical gardens, etc. Ex-situ conservation also includes the following:

  • In vitro fertilization of eggs, tissue culture techniques to rear endangered plant and animal species in lab conditions and relieving them in the wild when they are strong enough to sustain on their own.

  • Cryopreservation, where gametes from endangered species are preserved in viable conditions for a longer period.

  • Gene library where a collection of cloned genes that are big enough to contain a copy of every gene of an individual of a particular species is kept. It is a collection of total genomic DNA from one organism.

FAQ (Frequently Asked Questions)

1. What is Genetic Diversity?

Ans: Genetic diversity indicates a greater number of genetically different individuals within the same species. It is the way by which a population of organisms survive the changing environments. More genetic variation suggests a greater number of individuals with a variety of alleles that help sustain the organisms in the changing environment. These individuals most often produce offspring with the same alleles. In a generation when such genetically evolved individuals succeed to survive, they also let the continuation of their species.

2. How do Humans Affect Genetic Diversity?

Ans: Human population density and the area acquired by humans make an impact on animal gene diversity. Human interventions have caused a considerable environmental change causing genetic variation in various plant and animal species. Many species have evolved to sustain and survive the changing environment. This is how humans affect genetic diversity.