Biodiversity is the variety of plants and animals inhabiting in an ecosystem. It occurs at 3 different levels, namely, species diversity, genetic diversity and ecosystem diversity.
Each individual has a unique genetic architecture, which is determined by the hereditary material- DNA. Huge variety of gene sets equip a population to tolerate stress from a given environmental factor. Genetic diversity is one of the driving forces of evolution and the main criteria for natural selection which leads to survival of the fittest.
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What is Genetic Diversity?
Genetic diversity is defined as genetic variability present within species. Genetic diversity is the product of recombination of genetic material in the process of inheritance. It changes with time and space.
Sexual reproduction is important in maintaining genetic diversity as it gives unique offspring by combining genes of parents.
Mutation of genes, genetic drift and gene flow are also responsible for genetic diversity.
Importance of Genetic Diversity
- Genetic diversity gives rise to different physical attributes to the individual and capacity to adapt to stress, diseases and unfavourable environmental conditions.
- Environmental changes that are natural or due to human intervention, lead to the natural selection and survival of the fittest. Hence, due to genetic diversity, the varieties that are susceptible, die and the ones who can adapt to changes will survive.
- Genetic diversity is important for a healthy population by maintaining different varieties of genes that might be resistant to pests, diseases or other conditions.
- New varieties of plants can be grown by cross-breeding different genetic variants and produce plants with desirable traits like disease resistance, increased tolerance to stress.
- Genetic diversity reduces the recurrence of undesirable inherited traits.
- Genetic diversity ensures that at least there are some survivors of a species left.
Genetic Diversity Examples
- Different breeds of dogs. Dogs are selectively bred to get the desired traits.
- Different varieties of rose flower, wheat, etc.
- There are more than 50,000 varieties of rice and more than a thousand varieties of mangoes found in India.
- Different varieties of medicinal plant Rauvolfia vomitoria present in different Himalayan ranges differ in the amount of chemical reserpine produced by them.
Conservation of Genetic Diversity
Activities like specific selection for harvesting, destruction of natural habitats lead to loss of diversity.
Genes which get lost might be having many benefits, so it is important to conserve diversity for human well-being and to protect a species from getting extinct.
In cases of drought or a sudden outbreak of disease when the whole crop is destroyed, it is possible to grow genetically diverse and disease-resistant species by conserving diversity.
There are various methods to conserve biodiversity:
- In situ conservation: It is impossible to conserve the whole of biodiversity, so certain “hotspots” are identified and conserved to protect species that are endemic to a particular habitat and are threatened, endangered or at high risk of getting extinct. E.g. wildlife sanctuaries, national parks.
- Ex-situ conservation: Threatened plants and animals are taken out from their natural habitat and kept in a special setting to give them special care and protection. E.g. botanical gardens, zoos, wildlife safari etc.
- Using cryopreservation techniques, gametes of threatened species are preserved in viable and fertile conditions for a longer period of time.
- Eggs can be fertilised in-vitro and plants can be propagated through tissue culture.
- Genomic library is a recent advancement to conserve genetic diversity.