On the scaling of biodiversity distribution, variability, and fluctuation
It is paradoxical that life´s striking diversity and complexity can be understood as fluctuations around a common theme and that our strides to understand the issue of scale end up in a scale-free world! There is some inherent symmetry in the natural world, and scaling relationships can usually capture it in a simple way. We illustrate this symmetry by providing examples on the scaling of several aspects of biodiversity including traits, species and entire ecological systems and ask what processes are responsable for the emergence of scaling.
We show that the emergence of scaling in biodiversity is usually driven by some simple rules associated to constraints in resource use and availability, and simple physical processes such as percolation of species across space. Other biodiversity scalings, however, emerge from more complicated mechanisms that requiere a deep understanding of the factors affecting niche evolution and modularity (the existence of sub-systems of tightly interacting species). We end by making a plea to develop scale-free theories in ecology and exemplify this with neutral theory. Work supported by ICM P05-002, PFB-23, PIA-ACT 1112, and Centro de Bioestocástica PUC.