Tropical Species Diversity Pattern
Biogeographers have observed that tropical regions generally harbor more terrestrial species than temperate regions. This phenomenon has several proposed explanations.
Analyzing Explanations for Tropical Biodiversity
Several factors contribute to the higher species richness observed in the tropics:
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Higher Diversification Rates: Evolutionary processes, such as speciation, may occur at faster rates in the tropics, or extinction rates may be lower, leading to a greater accumulation of species over time.
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Higher Energy Inputs: Increased solar energy and temperature in tropical regions support higher primary productivity and biomass, which can sustain larger and more diverse ecosystems.
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Greater Land Area: Although definitions vary, the tropical belt often encompasses substantial landmass. Larger areas typically support more species due to the species-area relationship, allowing for larger populations and greater habitat heterogeneity.
Why Climatic Tolerance is NOT the Reason
The statement that tropical species have greater climatic tolerance is not a plausible explanation for higher tropical diversity. In fact, the opposite is often true:
- Tropical environments are typically characterized by stable climates with minimal seasonal variation.
- Species evolving in these stable conditions often become highly specialized and adapted to narrow environmental ranges.
- Conversely, temperate species must endure significant seasonal changes (e.g., cold winters, warm summers) and thus often possess broader climatic tolerance.
Therefore, greater climatic tolerance among tropical species is unlikely to be the reason for their higher numbers; specialization to stable conditions is more characteristic.
Important Questions from Biodiversity
- Which one of the following is an example of a cell type found only in a single phylum?
- The table below lists different insects and taxonomic orders. Choose the option that matches the animal to its correct taxonomic order.
Animal Taxonomic order P) Moths i) Hemiptera Q) True bugs ii) Orthoptera R) Crickets iii) Coleoptera S) Beetles iv) Lepidoptera v) Diptera - The mode of speciation in snakes in the Western Ghats is predominantly allopatric.A researcher wants to quantify diversification of snakes in this range. From theoptions given, choose the most cost and time efficient way to sample snakes.
- In which of the following plants is the dominant stage of the life cycle haploid?
- A scientist finds a new species of insect and sends a sample to a museum for confirmation. The curator of the museum designates it as a holotype for the newly identified species and asks the scientist to also provide samples of the opposite sex. This sample of the opposite sex is called the
