Evolutionary biogeography of Australian jumping spider genera (Araneae : Salticidae)

Abstract

Phylogenetic relationships and estimated dates of origin, plus distributional, ecological and morphological data for salticid genera were used to examine a series of hypotheses related to the evolution of the Australian salticid fauna. Though independent, the time patterns of evolution of genera in Australia and South America were similar, while that for Northern Hemisphere taxa differed. In each case the production of new genera occurred during the warmer parts of the mid Tertiary but not during cooler and drier times. Asian elements entered Australia as early as 31 million years ago, long before the collision of the Australasian and Asian continental plates. Endemic and derivatives of Asian genera were similarly distributed across Australian biomes. However, arriving taxa were more successful when conditions matched their mesic origins (tropical), but less so when different (temperate). While endemic genera often extended their ranges into drier environments by increasing the number of species, recent arrivals did so by extending the range of individual species. Maximum Parsimony analyses of a range of presumed adaptive, morphological and ecological characters showed these did not reflect genus-level processes; however, the analysis did show all endemic genera had mesic origins.