Open AccessEcosystem size predicts eco‐morphological variability in a postglacial diversification
Author(s) -
Recknagel Hans,
Hooker Oliver E.,
Adams Colin E.,
Elmer Kathryn R.
Publication year - 2017
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.3013
Subject(s) - abiotic component , ecology , salvelinus , ecomorphology , littoral zone , trophic level , foraging , lake ecosystem , arctic , biology , ecosystem , adaptive radiation , habitat , context (archaeology) , fishery , trout , fish <actinopterygii> , phylogenetics , biochemistry , paleontology , gene
Abstract Identifying the processes by which new phenotypes and species emerge has been a long‐standing effort in evolutionary biology. Young adaptive radiations provide a model to study patterns of morphological and ecological diversification in environmental context. Here, we use the recent radiation (ca. 12k years old) of the freshwater fish Arctic charr ( Salvelinus alpinus ) to identify abiotic and biotic environmental factors associated with adaptive morphological variation. Arctic charr are exceptionally diverse, and in postglacial lakes there is strong evidence of repeated parallel evolution of similar morphologies associated with foraging. We measured head depth (a trait reflecting general eco‐morphology and foraging ecology) of 1,091 individuals across 30 lake populations to test whether fish morphological variation was associated with lake bathymetry and/or ecological parameters. Across populations, we found a significant relationship between the variation in head depth of the charr and abiotic environmental characteristics: positively with ecosystem size (i.e., lake volume, surface area, depth) and negatively with the amount of littoral zone. In addition, extremely robust‐headed phenotypes tended to be associated with larger and deeper lakes. We identified no influence of co‐existing biotic community on Arctic charr trophic morphology. This study evidences the role of the extrinsic environment as a facilitator of rapid eco‐morphological diversification.