Sixth mass extinction
- June 5, 2020
- Posted by: admin
- Category: DPN Topics
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Subject: Environment/geography
Context:
Sixth mass extinction of wildlife accelerating, scientists warn
Concept:
- Mass extinction refers to a substantial increase in the degree of extinction or when the Earth loses more than three-quarters of its species in a geologically short period of time.
- So far, during the entire history of the Earth, there have been five mass extinctions. The sixth, which is ongoing, is referred to as the Anthropocene extinction.
- The earlier five mass extinctions that took place in the last 450 million years have led to the destruction of 70-95 per cent of the species of plants, animals and microorganisms that existed earlier.
- These extinctions were caused by “catastrophic alterations” to the environment, such as massive volcanic eruptions, depletion of oceanic oxygen or collision with an asteroid.
- After each of these extinctions, it took millions of years to regain species comparable to those that existed before the event.
- Further, attributing sixth mass extinction to humans, scientists said that one of the reasons that humanity is an “unprecedented threat” to many living organisms is because of their growing numbers.
- The loss of species has been occurring since human ancestors developed agriculture over 11,000 years ago. Since then, the human population has increased from about 1 million to 7.7 billion.