Founder effects initiated rapid species radiation in Hawaiian cave planthoppers

Abstract

The Hawaiian Islands provide the venue of one of nature's grand experiments in evolution. Here, we present morphological, behavioral, genetic, and geologic data from a young subterranean insect lineage in lava tube caves on Hawai'i Island. The Oliarus polyphemus species complex has the potential to become a model for studying rapid speciation by stochastic events. All species in this lineage live in extremely similar environments but show strong differentiation in behavioral and morphometric characters, which are random with respect to cave age and geographic distribution. Our observation that phenotypic variability within populations decreases with increasing cave age challenges traditional views on founder effects. Furthermore, these cave populations are natural replicates that can be used to test the contradictory hypotheses. Moreover, Hawaiian cave planthoppers exhibit one of the highest speciation rates among animals and, thus, radically shift our perception on the evolutionary potential of obligate cavernicoles.density-dependent selection | dynamic adaptive landscape | nonadaptive speciation | sexual behavior | vibrational communication

The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands

“…References: 1 See Table 3 for species diversity references 2 Hildenbrand et al (2004), Guillou et al (2005), Uto et al (2007) 3 Sherrod et al (2007) 4 DeSalle (1992); Russo et al (1995) 5 Wessel et al (2013) 6  Cohen et al (1993), Takahashi and Koblmüller (2011) 7 Genner et al (2007), Koblmüller et al (2008)…”

Iuiuia caeca gen. n., sp. n., a new troglobitic planthopper in the family Kinnaridae (Hemiptera, Fulgoromorpha) from Brazil

“…All three species were discovered within a few years and are the result of the exploration efforts of a single, but active team of speleologists. Given the vast extension of cavernous substrate in Brazil and the availability of suitable planthopper habitat, Brazil may soon join Hawaii (e.g., Fennah 1973a, Hoch and Howarth 1999, Wessel et al 2013, Australia (e.g., Fennah 1973b, Hoch and Howarth 1989a, b, Hoch 1990, 1993 and the Canary Islands (e.g., Remane and Hoch 1988, Hoch and Asche 1993 as another hotspot for cave planthopper diversity. It is to be hoped that legal measures for the conservation of the subterranean fauna of Brazilwhich constitutes one of the country's unique biological resources-will be developed and consequently reinforced.…”

Dispersal has inhibited avian diversification in Australasian archipelagoes

“…However, if speciation is predominantly the result of a colonization event (founder-event speciation sensu [4]), then an increase in dispersal ability should raise speciation rates, because it increases the chances of colonization of new areas. Speciation after colonization can be triggered by founder effects [5,6] or ecological speciation due to exposure to new habitats and selective pressures [7][8][9]. In addition, the relationship between dispersal ability and diversification may not be monotonic; instead, speciation rates may be maximized at intermediate levels of dispersal, as in the intermediate dispersal model [10][11][12].…”