The study of ecological communities and the 'community ecology' theory it has yielded includes a number of principles and mechanisms that describe how human disturbances as well as natural environmental variation can contribute to any of the above population level factors (33) . There are a number of implications to zoonotic disease emergence, although most have not yet been described in terms of disease emergence or in the medical, public health, or zoonotic disease literature. Of critical significance from this area of ecology is the general principle of community assembly. Research has demonstrated that communities of arranged predicably in terms of 'assembly rules' (34) . This order, in terms of the spatial distribution, composition and the abundance of each species in an ecological community, is affected by interspecific interactions (predation, competition, and parasitism). Density independent factors (e.g., weather, natural catastrophes) play an important, but a more ephemeral role in most ecosystems. The process of community assembly (and disassembly) has been particularly well demonstrated through studies of insular ecosystems, the so-called 'species area relationship,' and the phenomenon of faunal collapse (35) (36) (37) . A principal outcome and the ecological significance of this body of research first described in terms of the process of 'habitat fragmentation', has been identified as the principal mechanism by which human land and resource use contributes to species extinction (38) . Although initially debated, a significant amount of evidence has since accumulated resulting in its general acceptance and applicability, particularly to tropical forest ecosystems (36, 39, 40) .