Divergent evolution and niche differentiation within the common peatmoss Sphagnum magellanicum.

Journal Article (Journal Article)

Premise of the study

Populations with phenotypic polymorphism in discrete characters may be good models for investigating genome evolution and speciation. Sphagnum magellanicum Brid. is found throughout the northern hemisphere, and despite considerable variation in morphological characters, it is considered one of the least taxonomically controversial peatmoss species. We have observed two main morphs of the species associated with different microhabitats. Here we investigated the genomic and environmental basis of this intraspecific morphological variation.

Methods

We conducted transplant and common garden experiments to test whether the two morphs are genetically differentiated. We then used RAD-sequencing to quantify the genomic divergence between the morphs and approximate Bayesian computation (ABC) to infer the most likely demographic scenario explaining the genome-wide differentiation of the two morphs.

Key results

We found that genomic differentiation between the two morphs is unexpectedly high and that several of the differentiated morphological characters have a genetic basis. Using simulation approaches, we found support for a scenario of ancient divergence followed by recent secondary contact.

Conclusions

We show that the two morphs represent the two main genetic clusters previously found worldwide. Our results demonstrate that relatively minor morphological differentiation in a presumed phenotypically plastic peatmoss may be associated with massive divergence across the genome.

Full Text

Duke Authors

Cited Authors

  • Yousefi, N; Hassel, K; Flatberg, KI; Kemppainen, P; Trucchi, E; Shaw, AJ; Kyrkjeeide, MO; Szövényi, P; Stenøien, HK

Published Date

  • July 2017

Published In

Volume / Issue

  • 104 / 7

Start / End Page

  • 1060 - 1072

PubMed ID

  • 28754766

Electronic International Standard Serial Number (EISSN)

  • 1537-2197

International Standard Serial Number (ISSN)

  • 0002-9122

Digital Object Identifier (DOI)

  • 10.3732/ajb.1700163

Language

  • eng