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Current Affairs

Why elephants and Tigers did not go extinct in India?

Date: 21 December 2020 Tags: Miscellaneous

Issue

A study documenting four extinctions of large mammals on the Indian Subcontinent sheds light on why elephants, tigers, and rhinos still roam there.

 

Background

The persistence of mammalian megafauna in the Indian Subcontinent is related to the great beasts' long coexistence there with Homo sapiens and other human ancestors.

 

Details

  • The study is based on a novel dataset drawn from 51 fossil sites in present-day India and documents a low-magnitude extinction that began about 30,000 years ago. That was about 30,000 years after modern humans arrived in the Indian Subcontinent.

  • The analysis provides the first direct and independent test of the "co-evolution hypothesis," a commonly held theory that the magnitude of an extinction correlates with the amount of time that large mammals coexist with humans and their hominin ancestors.

  • The research supports the idea that some large species co-evolved with human ancestors, adapting to their presence and developing behaviours that helped them cope with how they altered the habitat.

  • The researchers document the extinctions of two species of elephant, a zebra-like horse. They also show the local extinction of ostriches, which survive elsewhere, and the "pseudo-extinction" of the Indian aurochs, the wild ancestor of the domestic zebu cattle that thrive in India today.

  • The four extinctions represent about 4% of mainland India's mammalian fauna and 20% of its mammalian megafauna, animals weighing more than 50 kilograms.

  • The extinction rate in India over the past 50,000 years is comparable to that of eastern and southern Africa, but 2.5 times smaller than in South America and 4 times smaller than in North America, Europe, Madagascar, and Australia.

  • The researchers also analyzed the role of contemporary climate change trends -- including temperature fluctuations and varying monsoon intensity on the extinction pattern. 

  • The researchers found that climate change alone does not explain the low-magnitude but strongly size-biased extinction that they documented.

  • The researchers noted that all of the extinct species they identified had survived periods of drought.

  • The researchers also note that Asian elephants, tigers, and other large mammals in India had extensive ranges extending from Turkey to Southeast Asia, which improved their chances of survival. 

 

Extinction

Extinction is the termination of a kind of organism or of a group of kinds, usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point.