Extinction of species is one of the major threats to biodiversity. In this article we shall discuss the factors which contribute to extinction.
What is extinction ?
Extinction of species refers to disappearance of species from earth. By species being extinct, we mean that even the last surviving member of the species dies.
What are the types of extinction ?
Extinction may be categorized into three types :
1. Natural Extinction – It refers to slow replacement of existing species by more advanced and adapted species due to environmental conditions.
2. Mass Extinction – It refers to large scale extinction due to catastrophe. For example: Extinction of dinosaurs is an example of mass extinction.
3. Anthropogenic Extinction– It refers to extinction of species due to human activities. Many species have become extinct due to human activities. for example Dodo bird became extinct due to extensive hunting.
What are the factors contributing to extinction which is the major threat to biodiversity ?
1. Forest fires – have led to extinction of many species in the past. These forest fires may be attributed to human activities or natural factors.
2. Hunting – Large scale killing of wild animals for trade of animal products such as hides, skins, ivory, horns, fur, leather, meat etc has lead to extinction of many species. Use of plant and animal products in cosmetics and drugs are adding to the woe of species in danger. Over fishing of marine and fresh water resources is posing threat to many aquatic species. Dodo a unique bird of Mauritius, have disappeared due to excessive hunting.
3. Introduction of exotic species – It increases competition for food and space. Exotic species are the species that are foreign to the territory i.e are not native to the territory, and get introduced in the natural environment either accidentally or intentionally by human activities. For example, Introduction of American cockroach Periplaneta americana, got introduced into India with food carrying ships, is vastly replacing native Indian oriental cockroach, Blatta orientalis.
Water Hyacinth became a serious problem in several ecosystems.
4. Destruction of Habitats– Habitat of many species are getting destroyed due to :
iii- Human developmental activities
5- Co-extinction– Many species in their natural habitat are mutually dependent on one another for each others existence. In such cases , if one species gets extinct , the other one dependent upon the previous meets the same fate of extinction.
What are the methods to combat the factors that are threats to biodiversity?
1. Excessive hunting, poaching must be curtailed.
2. More stress should be laid on afforestation.
3. Steps must be taken to save the endangered species from extinction.
4. Human developmental activities must be undertaken after assessing their impact upon the environment.
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