Question

Q69) In general, species diversity decreases as we move from the equator towards the poles. Consider the following statements.

i) Tropical latitudes have been subjected to frequent glaciations in the past.

ii) Tropical environments are less seasonal.

iii) More solar energy is available at the tropics in comparison to temperate and polar regions.

Which of the above can be said to be the reason/reasons for higher species diversity near the equator?

• A. a) ii only
• B. b) i and iii only
• C. c) i, ii and iii
• D. d) ii and iii only

Answer 1

The correct option is D d) ii and iii only

D)

Explanation:

• Speciation is generally a function of time, unlike temperate regions subjected to frequentglaciations in the past, tropical latitudes have remained relatively undisturbed for millions ofyears and thus, had a long evolutionary time for species diversification.
• Tropicalenvironments, unlike temperate ones, are less seasonal, relatively more constant andpredictable. Such constant environments promote niche specialisation and lead to a greater species diversity.
• There is more solar energy available in the tropics, which contributesto higher productivity; this in turn might contribute indirectly to greater diversity.