Inferring the mode of speciation in Indo‐West Pacific Conus (Gastropoda: Conidae)

Abstract

Aim This study aims to initially explore the mode of speciation in Indo‐West Pacific Conus. Location The Indo‐West Pacific island arc, Indian and Pacific Oceans. Methods Relating evolutionary divergence in a molecular phylogeny [T.F. Duda & S.R. Palumbi (1999) Proceedings of the National Academy of Science USA, 96, 10272] using node height with modern range extents as a possible measure of allopatric or sympatric speciation following that of T.G. Barraclough, A.P. Vogler & P.H. Harvey [(1999) Evolution of Biological Diversity. Oxford University Press, Oxford] models of sympatric and allopatric speciation. Results The analysis seems to indicate that the relationship of sympatry with node height is not informative. Species that have diverged quite recently show 100% sympatry with the sister species. A clearer signal of recent allopatric speciation is observed in species whose distribution is at the edge of the Indian and Pacific Ocean basins. In the widely distributed Conus ebraeus clade, the relationships of node heights and range extents of the member species support a key prediction of sympatric speciation. In highly ecologically specialized species, there is a smaller degree of sympatry than those species that are less specialized. Main conclusions The modes of speciation models presented in this study are not informative. This suggests that there had been large and possibly rapid changes in range size after speciation in the various clades. This could have been due to the fact that the wide dispersal life‐history strategy in the genus had been largely conserved in Conus evolution. There is evidence of sympatric and parapatric speciation in one Conus clade. Overall, the patterns of phylogeny and range distribution when related to the timing of speciation lend circumstantial support to a Neogene centre of origin hypothesis but not to speciation on the Pacific Plate. Speciation is likely to have been associated with the Tethys Sea closure event, with rapid speciation occurring after closure.

The relative importance of geography and ecology in species diversification: evidence from a tropical marine intertidal snail (Nerita)

“…While most recently split sister species appear allopatric, sister taxa often show range overlap at one or two nodes deeper in the phylogeny. In contrast, a single clade ( Argonerita ) comprising the sister species N. signata and N. histrio exhibited a pattern similar to that expected under sympatric speciation, with a high intercept and negative slope (for a similar finding within Conus , see Vallejo, 2005). However, the present analyses failed to yield statistically significant relationships between the degree of overlap and age of divergence.…”

“…mixed modes), frequent or rapid post‐speciation range shifts (e.g. Vallejo, 2005) or too few species within each clade (Barraclough & Vogler, 2000; Losos & Glor, 2003; Fitzpatrick & Turelli, 2006). In this study, the majority of Nerita clades exhibited a signature of either allopatric or sympatric speciation, rather than a signal of mixed modes or rapid post‐speciation range shifts.…”

A phylogenetic test of multiple proposals for the origins of the East Indies coral reef biota

“…Many more phylogenies of Indo-Pacific taxa are now available (e.g. Bernardi et al, 2004;Vallejo, 2005;Read et al, 2006). However, in order to demonstrate the flaws which result from using BPA or component analysis with numerous widespread taxa, we restricted the analysis to the same taxa used by Santini & Winterbottom (2002), so that the differences found are attributable solely to variations in methodology, and not to taxon sampling.…”

Loss of planktotrophy and speciation: geographical fragmentation in the deep-water gastropod genusBathytoma(Gastropoda, Conoidea) in the western Pacific

“…Several factors have been proposed to drive these patterns, focusing mainly on dispersal capacities (Collin, 2003;Meyer et al, 2005;Vallejo, 2005) and ecological ranges (Bierne et al, 2003). In this context, marine molluscs are of particular interest as their dispersal capacities can be easily inferred from protoconch morphology (see e.g.…”