Individuals within each species have their own collection of genes. A gene is a hereditary unit that allows future generations to inherit the characteristics of their parents. The nucleotide sequence in the DNA strands is bundled in chromosomes referred to as genes.
Genes determine the differences and similarities across various organisms. They are responsible for the expression of the distinguishing properties of different species. The difference in genes is accountable for the variation among the members of a population. Human populations, for example, are made up of people with a variety of physical characteristics that reflect their genetic diversity. Genetic variety can be found within species as well as between them. Different breeds of dogs, for example, may make up a dog population.
Definition of genetic diversity
Genetic diversity is defined as the total number of various alleles within a species or population. Variations between a large number of different species and variations within a species are both referred to as genetic diversity.
Importance of genetic diversity
The importance of genetic diversity may be discussed as follows:
- Maintaining distinct kinds of genes, which may be resistant to pests, diseases, or other situations, is crucial for a healthy population.
- Unwanted inherited features are less likely to repeat when there is more genetic variety.
- Genetic diversity ensures that at least some members of a species will survive.
- Individuals with diverse physical qualities and the ability to adapt to stress, diseases, and unfavourable environmental conditions have different genetic diversity.
- Natural or anthropogenic changes in the environment result in natural selection and the survival of the fittest.
- As a result of genetic variation, vulnerable kinds perish while those that can adapt to change thrive.
Examples of genetic diversity
Humans have a lot of genetic variation. They have different eye colours, hair colours, skin colours, heights and so on. Identification procedures such as fingerprinting rely on the diversity of the human population. Human genetic diversity is particularly high in isolated populations when human population variety is minimal compared to overall human variation. Genetic diversity is found in all types of plants and animals. We find innumerable varieties of flowers, fruits, vegetables etc. In India, there are about 50,000 varieties of rice and over a thousand varieties of mangoes.
Factors contributing to genetic diversity
Mutations: Changes in the nucleotide sequence of DNA are known as mutations. Mutations are caused primarily by the replacement or alteration of genes and chromosomes. Mutations can result in the emergence of new alleles, altering the genetic structure of a population. Mutations that occur by chance are uncommon. They have a negligible effect in changing the genetic structure of a population. Since mutations have a negligible impact for a short period of time, evolution is not controlled by mutations.
Genetic Drift: A random variation in the frequency of a particular allele in a population from generation to generation is caused by chance sampling events, which is less pronounced in large populations. The random selection of some alleles to be inherited by offspring causes genetic drift.
Gene Flow or Gene Migration: Gene flow refers to the production of new generations with a certain allele that has been passed down from a donor population to a recipient population. This allele is found in each of them at different frequencies. Pollen, for example, may be transferred to far locations by wind, which carries alleles from one group to another with a low allele frequency. A species, on the other hand, is the greatest unit within which gene flow can easily occur.
Natural Selection: It is a process in which the gene pool of a population changes as individuals who can withstand environmental changes reproduce. It is an important way of population adaptation to environmental conditions during evolution. Individuals can use physiological ways to resist environmental effects in the short term. On the other hand, long-term resistance necessitates modifying the genetic mix of the population.
Conservation of genetic diversity
The loss of diversity is caused by activities such as selective harvesting and the destruction of natural habitats. Genes that are lost may have numerous benefits. Thus it is critical to preserve diversity for human well-being and to prevent the extinction of a species. By retaining diversity, it is feasible to develop genetically varied and disease-resistant species in the event of drought or a rapid outbreak of disease that wipes out the entire crop.
Biodiversity conservation can be accomplished in a number of ways,
- Hotspots of Endangered species: Since it is impossible to conserve all of biodiversity, certain “hotspots” are identified and protected to protect species that are endemic to a certain ecosystem and are threatened, endangered, or are on the verge of extinction. Wildlife refuges and national parks are examples of such hotspots of conservation.
- Ex-situ Conservation: Endangered plants and animals are removed from their original environment and cared for and protected in a particular setting. Botanical gardens, zoos, animal safaris are examples of ex-situ conservation.
Conclusion
DNA is a genetic code found in all living organisms on the planet. DNA is arranged into genes in the same manner that letters are arranged into words. Our bodies receive instructions on how to work from our genes. Even among members of the same species, the exact DNA coding varies. This is referred to as genetic diversity. The shape of bird beaks, the flavour of tomatoes, and even the colour of your hair are all influenced by genetic variation. Genetic variety is crucial because it increases the chances of survival of a species. When populations become smaller and isolated, genetic diversity is lost, reducing the ability of a species to adapt and thrive.