Pleistocene climate change promoted rapid diversification of aquatic invertebrates in Southeast Australia

BMC Evolutionary Biology

Research Article

Marianne Espeland¹  Martin J Genner²  Lars Hendrich³  Oliver Hawlitschek³  Emmanuel FA Toussaint³  Michael Balke⁴ 

[1] Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, 02138, Cambridge, MA, USA;School of Biological Sciences, University of Bristol, Woodland Road, BS8 1UG, Bristol, UK;Zoologische Staatssammlung, Münchhausenstr. 21, 81247, Munich, Germany;Zoologische Staatssammlung, Münchhausenstr. 21, 81247, Munich, Germany;GeoBioCenter, Ludwig-Maximilians-Universität, Richard-Wagner-Str. 10, 80333, Munich, Germany;

关键词: Mismatch Distribution;    Ecological Niche Modeling;    Incomplete Lineage Sorting;    Diversification Rate;    Rapid Radiation;   

DOI  :  10.1186/1471-2148-12-142

 received in 2012-02-27, accepted in 2012-07-30,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundThe Pleistocene Ice Ages were the most recent geohistorical event of major global impact, but their consequences for most parts of the Southern hemisphere remain poorly known. We investigate a radiation of ten species of Sternopriscus, the most species-rich genus of epigean Australian diving beetles. These species are distinct based on genital morphology but cannot be distinguished readily by mtDNA and nDNA because of genotype sharing caused by incomplete lineage sorting. Their genetic similarity suggests a Pleistocene origin.ResultsWe use a dataset of 3858 bp of mitochondrial and nuclear DNA to reconstruct a phylogeny of Sternopriscus using gene and species trees. Diversification analyses support the finding of a recent rapid speciation event with estimated speciation rates of up to 2.40 species per MY, which is considerably higher than the proposed average rate of 0.16 species per MY for insects. Additionally, we use ecological niche modeling and analyze data on habitat preferences to test for niche divergence between species of the recent Sternopriscus radiation. These analyses show that the species can be characterized by a set of ecological variables referring to habitat, climate and altitude.ConclusionsOur results suggest that the repeated isolation of populations in glacial refugia might have led to divergent ecological adaptations and the fixation of morphological traits supporting reproductive isolation and therefore may have promoted speciation. The recent Sternopriscus radiation fulfills many characteristics of a species flock and would be the first described example of an aquatic insect species flock. We argue that the species of this group may represent a stage in speciation past the species flock condition because of their mostly broad and often non-overlapping ranges and preferences for different habitat types.

【 授权许可】

CC BY   
© Hawlitschek et al.; licensee BioMed Central Ltd. 2012