Question

Find the odd one out with respect to the ‘Evil Quartet’.

• A. Narrowly utilitarian
• B. Habitat loss and fragmentation
• C. Over exploitation
• D. Invasion of alien species

Answer 1

The correct option is A Narrowly utilitarian

There is an increased rate of biodiversity loss due to various human activities. The concept of the ‘Evil Quartet’ was introduced by Jarod Diamond as an alternate word to describe the causes for biodiversity loss. It describes the four major causes:

• Habitat loss and fragmentation - This occurs due to increasing demand for land for an exponentially increasing population. Forests are cut down for the purpose of urbanisation or agricultural purposes which lead to loss of habitat for several species. For example, the Amazon rainforest which harboured the greatest variety of species on earth and covered 14% of the total land now covers less than 6%. Therefore there was destruction of habitat. Destruction of such large habitats leads to fragmentation. Birds (especially migratory birds) and mammals that require large territories are affected by habitat loss and fragmentation.
• Overexploitation - Overuse of natural resources by humans leads to overexploitation of resources. For example: Steller’s sea cows of Russia were overexploited by humans; as a result they became extinct.
• Alien species invasions - Introduction of alien species purposefully or unintentionally in a habitat can cause decline of the native species as some of the alien species turn invasive and outcompete the indigenous species in a habitat. For example, African catfish called Clarias gariepinus are becoming a threat to the native catfishes in the rivers of India.
• Co-Extinctions - When some species become extinct, some other plant or animal species, associated with it in an obligatory relationship, also becomes extinct. For example, protozoans, ciliates which are fish parasites will also become extinct if the host fish becomes extinct.

Narrowly utilitarian is the category of reasons to conserve biodiversity as humans get direct benefit in the form of food, firewood, fibre, construction material, industrial products, and products of medicinal value from nature. Hence, the other three options belong to the reason for the loss of biodiversity; narrowly utilitarian is the odd one out as it is a reason for conservation.