Which of the following is a reason for the greater biological diversity of tropical regions ?

Answer: DSolution: Higher diversity in tropical areas is because of various factors. (i) Speciation is a function of time. Temperature areas have undergone frequent glaciation in the past. It killed most of the species. No such disturbance occurred in tropics where species continued to flourish and evolve undistubed for millions of years. (ii) There are no unfavourable seasons in tropics. Continued favourable environment has helped tropical oraganisms to gain more niche specialisation and increased diversity. (iii) More solar energy is available in tropics. This promotes higher productivity and increased biodiversity. (iv) Resource availability is higher in tropics. (v) There is reduced competition in tropics due to favourable environment. (vi) Rate of extinction is low in tropics.