Data from: General models of ecological diversification. II. Simulations and empirical applications

Models of functional ecospace diversification within life-habit frameworks
(functional-trait spaces) are increasingly used across community ecology,
functional ecology, and paleoecology. In general, these models can be
represented by four basic processes, three that have driven causes and one
that occurs through a passive process. The driven models include
redundancy (caused by forms of functional canalization), partitioning
(specialization), and expansion (divergent novelty), but they also share
important dynamical similarities with the passive neutral model. In this
second of two companion articles, Monte Carlo simulations of these models
are used to illustrate their basic statistical dynamics across a range of
data structures and implementations. Ecospace frameworks with greater
numbers of characters (functional traits) and ordered (multistate)
character types provide more distinct dynamics and greater ability to
distinguish the models, but the general dynamics tend to be congruent
across all implementations. Classification-tree methods are proposed as a
powerful means to select among multiple candidate models when using
multivariate data sets. Well-preserved Late Ordovician (type Cincinnatian)
samples from the Kope and Waynesville formations are used to illustrate
how these models can be inferred in empirical applications. Initial
simulations overestimate the ecological disparity of actual assemblages,
confirming that actual life habits are highly constrained. Modifications
incorporating more realistic assumptions (such as weighting potential life
habits according to actual frequencies and adding a parameter controlling
the strength of each model’s rules) provide better correspondence to
actual assemblages. Samples from both formations are best fit by
partitioning (and to lesser extent redundancy) models, consistent with a
role for local processes. When aggregated as an entire formation, the Kope
Formation pool remains best fit by the partitioning model, whereas the
entire Waynesville pool is better fit by the redundancy model, implying
greater beta diversity within this unit. The ‘ecospace’ package is
provided to implement the simulations and to calculate their dynamics
using the R statistical language.