Indies (Briggs, 1995, 1999a,b, 2000, 2003, 2007). Although much evidence supports this hypothesis, species of reef fish are not consistently young in the IAA and old in peripheral regions (Barber and Bellwood, 2005), and the present study suggests that, in reef stomatopods, both speciation and extinction are high in peripheral areas as well as in the IAA.
High species diversity itself may promote diversification [Emerson and Kolm (2005), but see Cardena et al. (2005)], probably through species interactions. Speciation rates in three groups of fossil plankton over 2–20 Myr correlate with species diversity independent of sampling intensity and area (Allen and Gillooly, 2006). In the present study, species interactions in diverse assemblages may cause shifts in body size and consequent changes in life history patterns and speciation/extinction patterns.
We will suggest that the biotic and environmental processes that govern body size and life history traits drive rates of speciation/extinction and thus patterns of diversity in IWP stomatopods and other reef organisms.
Endemism has been of particular interest as an indicator of extinction. The concept of biodiversity hotspots—concentrations of endemic species that are at exceptional risk—was motivated by the need to establish conservation priorities (Myers, 1988; Reid, 1998; Myers et al., 2000; Mittermeier et al., 2004). However, some authors have argued that high overall diversity or phylogenetically unique taxa or habitats deserve priority attention, and others have shown that centers of endemism do not always coincide among taxa or with degree of threat (Prendergast et al., 1993; Williams et al., 1996; Bonn et al., 2002; Orme et al., 2005). For some of the same reasons, hotspots on global coral reefs have been controversial (Baird et al., 2002; Briggs, 2002; Hughes et al., 2002; Roberts et al., 2002). Here we examine patterns of endemism in the context of both speciation and extinction, because limited ranges occur during both processes. Conservation of areas rich in endemics is important not only because they are at particular risk of species loss but also because they represent potential sources of diversification.
Endemism in reef stomatopods varies with scale. When stomatopods are known from only a single locality, these “local endemics” are widely scattered (Fig. 3.4), with no significant relationship between number of