Abstract
Tropical mountains are usually characterized by a vertically-arranged sequence of ecological belts, which, in contrast to temperate habitats, have remained relatively stable in space across the Quaternary. Such long-lasting patterning of habitats makes them ideal to test the role of environmental pressure in driving ecological and evolutionary processes. Using Sumatran freshwater mayfly communities, we test whether elevation, rather than other spatial factors (i.e. volcanoes, watersheds) structures both species within communities and genes within species. Based on the analysis of 31 mayfly (Ephemeroptera) communities and restriction-site-associated-DNA sequencing in the four most ubiquitous species, we found elevation as the major spatial component structuring both species and genes in the landscape. In other words, similar elevations across different mountains or watersheds harbor more similar species and genes than different elevations within the same mountain or watershed. Tropical elevation gradients characterized by environmental conditions that are both steep and relatively stable seasonally and over geological time scales, are thus responsible for both ecological and genetic differentiation. Our results demonstrate how in situ ecological diversification at the micro-evolutionary level might fuel alpha- and beta- components of diversity in tropical sky islands.
Highlights
Understanding the underlying mechanisms shaping the distribution of biodiversity is a key question in ecology[1]
We tested the effect of three spatial factors, i.e., elevation, volcanoes and watersheds on the spatial structuring of species within communities and genes within species in tropical freshwater organisms
Results revealed that elevation is a major factor explaining community composition of mayflies on tropical volcanoes and that similarity in species composition between communities decreases as elevational difference increases (Supplementary Fig. S3)
Summary
Understanding the underlying mechanisms shaping the distribution of biodiversity is a key question in ecology[1]. A large number of different biotic and abiotic conditions are found along tropical elevation gradients, which are prone to select for a high variety of ecological traits within communities and selection-mediated lineage divergence (if not impeded by gene flow) within species[20]. For many aquatic invertebrates the degree of connectivity between populations is determined by the interaction between dispersal traits and the landscape structure[25,26] Due to their short adult life span, mayflies generally have limited long distance dispersal, which may potentially increase the level of spatial aggregation of species and genes[27]. Most mayflies are highly sensitive to biotic and abiotic variations[28], which makes them ideal model organisms to investigate ecological and evolutionary processes at a narrow spatial scale
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
