Mutualism with sea anemones triggered the adaptive radiation of clownfishes

BMC Evolutionary Biology

Nicolas Salamin¹  Niklaus E Zimmermann²  Peter B Pearman²  Rafael O Wüest²  Carrie A Sims³  Glenn Litsios¹ 

[1] Swiss Institute of Bioinformatics, Génopode, Quartier Sorge, 1015, Lausanne, Switzerland;Landscape Dynamics, Swiss Federal Research Institute WSL, 8903, Birmensdorf, Switzerland;Ecological and Evolutionary Genetics Lab / Coral Reef Ecology Lab, School of Biological Sciences, The University of Queensland, 4072, St Lucia, Australia

关键词: Pomacentridae;    Brownian Motion;    Evolutionary rate;    Comparative method;    Diversification;    Ecological speciation;   

Others  :  1140107
DOI  :  10.1186/1471-2148-12-212

 received in 2012-06-06, accepted in 2012-10-27,  发布年份 2012

【 摘 要 】

Background

Adaptive radiation is the process by which a single ancestral species diversifies into many descendants adapted to exploit a wide range of habitats. The appearance of ecological opportunities, or the colonisation or adaptation to novel ecological resources, has been documented to promote adaptive radiation in many classic examples. Mutualistic interactions allow species to access resources untapped by competitors, but evidence shows that the effect of mutualism on species diversification can greatly vary among mutualistic systems. Here, we test whether the development of obligate mutualism with sea anemones allowed the clownfishes to radiate adaptively across the Indian and western Pacific oceans reef habitats.

Results

We show that clownfishes morphological characters are linked with ecological niches associated with the sea anemones. This pattern is consistent with the ecological speciation hypothesis. Furthermore, the clownfishes show an increase in the rate of species diversification as well as rate of morphological evolution compared to their closest relatives without anemone mutualistic associations.

Conclusions

The effect of mutualism on species diversification has only been studied in a limited number of groups. We present a case of adaptive radiation where mutualistic interaction is the likely key innovation, providing new insights into the mechanisms involved in the buildup of biodiversity. Due to a lack of barriers to dispersal, ecological speciation is rare in marine environments. Particular life-history characteristics of clownfishes likely reinforced reproductive isolation between populations, allowing rapid species diversification.

【 授权许可】

   
2012 Litsios et al.; licensee BioMed Central Ltd.

【 图 表 】

Figure 1.