Inverse latitudinal gradients in species diversity

Regional patterns of continental shelf polychaete diversity: examples for the North Sea, English Channel, Irish Sea and Outer Bristol Channel areas

“…The general circulation in the North Sea varies little with seasons and is in general cyclonic; Atlantic waters entering the North Sea from the north do not reach the continental coastline but turn gradually eastward towards the Jutland coast and the Skagerrak . The lack of a decline in diversity of polychaetes and other macrobenthic groups with latitude has also been documented by several authors (Kendall & Aschan 1993;Dauvin et al 1994;Kendall 1996;Ellingsen & Gray 2002;Kindlmann et al 2007;Renaud et al 2009), and as stated by the latter it could also be a consequence of the limited latitudinal range that only spans about 12…”

“…The decrease in diversity with increasing latitude and depth is a well-documented pattern that has been described for some marine groups such as copepods, gastropods and bivalves (Rex et al 1993;Rombouts et al 2009), although an increasing number of researchers have shown that this pattern is not as universal as it was thought to be (Clarke 1992;Heip et al 1992;Roy et al 2000;Kindlmann et al 2007;Rees et al 2007). Dauvin et al (1994), using a smaller database, had already shown this for polychaetes of the northeastern Atlantic.…”

Contrarian clade confirms the ubiquity of spatial origination patterns in the production of latitudinal diversity gradients

“…Additional research is needed to resolve these issues. Analyses of other contrarian clades in a dynamic, phylogenetic context, from aquatic macrophytes (37,38) to articulate brachiopods (25) to ichneumonid wasps (16,39), would be valuable.…”

“…Virtually all of this work has focused on groups showing standard LDGs, with many potential controlling variables inevitably correlated with latitude and therefore with one another. However, the relatively small subset of taxa showing weak or even reversed gradients (7,10,(13)(14)(15)(16) relative to the standard LDG must also be accounted for in any theory of the formation of the global LDG. Here, we take advantage of the well sampled biogeography and rich fossil record of shallow-water marine bivalves to test evolutionary models for the LDG by using a major contrarian order, the Anomalodesmata.…”

Reverse latitudinal diversity gradients, exceptions that prove the rule?

“…De esta forma, un huésped común permitiría a su parasitoide especialista encontrarle con mayor facilidad y aumentar así su posibilidad de supervivencia. Por lo tanto, existirá una mayor cantidad de especies parasitoides especialistas de este grupo de huéspedes conforme aumenta la latitud (Dixon et al 1987;Kindlmann 1988;Kindlmann et al 2007). …”