The central question in this review is whether the global and local patterns of biodiversity and abundance distribution dynamics are only subject to general statistical laws, such as these predicted by the Central Limit Theorem (CLT) and Unified Neutral Theory of Biodiversity (UNTB), or whether ecological mechanisms are important too for structuring the biodiversity of our planet. The mathematical foundations of the UNTB appear to rely on some principle of gate-keeping of biological data. An important role of the gate-keeping principle is detected in various biodiversity estimates. Besides, the question has risen whether the ecological dimension of the world’s ecosystems can be adequately described in terms of mathematical distributions and whether alternative abundance distributions are better suited to fit the experimental data.
1. Introduction: common species and specialists
2. Long distance similarities, Gate-keeping and Biodiversity
3. Statistics for species abundance distributions
4. Pros and Cons of Hubbell’s Unified Neutral Theory of Biodiversity (UNTB)
5. Alternative prospects: towards a (fractal) Global Ecosystem Approach (GEA)
Keywords : Biodiversity, Unified Neutral Theory of Biodiversity and Biogeography (UNTB), Metacommunities, Gate-keeping principle, Species Abundance distributions, Fractal Global Ecosystem Approach (fGEA).