Data from: When should species richness be energy limited, and how would we know?

Energetic constraints are fundamental to ecology and evolution, and
empirical relationships between species richness and estimates of
available energy (i.e. resources) have led some to suggest that richness
is energetically constrained. However, the mechanism linking energy with
richness is rarely specified and predictions of secondary patterns
consistent with energy-constrained richness are lacking. Here, we lay out
the necessary and sufficient assumptions of a causal relationship linking
energy gradients to richness gradients. We then describe an
eco-evolutionary simulation model that combines spatially explicit
diversification with trait evolution, resource availability and
assemblage-level carrying capacities. Our model identified patterns in
richness and phylogenetic structure expected when a spatial gradient in
energy availability determines the number of individuals supported in a
given area. A comparison to patterns under alternative scenarios, in which
fundamental assumptions behind energetic explanations were violated,
revealed patterns that are useful for evaluating the importance of
energetic constraints in empirical systems. We use a data set on rockfish
(genus Sebastes) from the northeastern Pacific to show how empirical data
can be coupled with model predictions to evaluate the role of energetic
constraints in generating observed richness gradients.