Author's accepted version (post-print).This is the peer reviewed version of the following article: Jüterbock, A., Franssen, S.U., Bergmann, N., Gu, J., Coyer, J.A., Reusch, T.B.H., ... Olsen, J.L. (2016). Phylogeographic differentiation versus transcriptomic adaptation to warm temperatures in Zostera marina, a globally important seagrass. Molecular Ecology, which has been published in final form at http://dx.doi.org/10.1111/mec.13829. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Available from 23/09/2017.