  The species-area relationship is one of the central generalizations in
ecology however its origin has remained a puzzle. Since ecosystems are
understood as energy transduction systems, the regularities in species richness
are considered to result from ubiquitous imperatives in energy transduction.
  From a thermodynamic point of view, organisms are transduction mechanisms
that distribute an influx of energy down along the steepest gradients to the
ecosystem's diverse repositories of chemical energy, i.e., populations of
species. Transduction machineries, i.e. ecosystems assembled from numerous
species, may emerge and evolve toward high efficiency on large areas that hold
more matter than small ones. This results in the well-known logistic-like
relationship between the area and the number of species. The species-area
relationship is understood, in terms of thermodynamics, to be the skewed
cumulative curve of chemical energy distribution that is commonly known as the
species-abundance relationship.
