Application of niche modelling to analyse biogeographic patterns in Palaeozoic brachiopods: evaluating niche stability in deep time

THE GEOGRAPHIC area inhabited by a species is constrained by its ecological niche, the multidimensional set of environmental variables that determines where members of a species can survive and maintain viable populations (Grinnell 1917). Individual organisms have the physiological capacity to inhabit any geographic location characterised by physical parameters within the constraints of the species’ fundamental niche, although most species actually occupy a smaller, realised niche that is further constrained by biotic interactions such as predation and competition (Hutchinson 1957; Soberón 2007). A species’ geographic distribution may be further limited due to stochastic processes, dispersal limitations, or source-sink dynamics which are encapsulated in the “mechanistic” or population growth-based niche concepts (Liebold 1995; Liebold et al. 2004; Tomašových & Kidwell 2009). Fundamentally, however, the ecological niche exerts a primary control on species distribution because populations of the species cannot exist outside the bounds of the environmental gradients that condition species presence or absence. This study, therefore, focuses on estimating the physical parameters associated with species’ ecological niches and how the definitions of the physical parameters of those niches change over geologic time. A fundamental question about evolution is whether species adjust to environmental and biotic changes in their ecosystem by maintaining STIGALL, A.L., 2011:07:29. Application of niche modelling to analyse biogeographic patterns in Palaeozoic brachiopods: evaluating niche stability in deep time. Memoirs of the Association of Australasian Palaeontologists 41, 229-255. ISSN 0810-8889.