Explanation

There are various hypothesis for higher diversity in tropical areas (i) Speciation is a function of time. Temperate 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 evolved undisturbed for millions of years (ii) There are no unfavourable seasons in tropics. Continued favourable environment has helped tropical organisms to gain more niche spec ialisation 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