Mutualism Evolution

One of my main research interests is why cooperation among species evolves. I use a number of different cooperative interactions between species – or mutualisms – as models to study this question. My research mostly focuses on the ecologically and evolutionarily crucial mutualisms of plants and soil microbes. I study plant-mycorrhizal mutualisms (Arbuscular Mycorrhizal Fungi, or AMF, and Ectomycorrhizal Fungi, or ECM). Moreover I study mutualisms among plants and nitrogen-fixing bacteria (rhizobial bacteria and actinorhizal mutualisms). 

My research applies economic and evolutionary theory to study evolution of cooperation. I use game theory to examine how mutualisms evolve, experimental approaches to study context-dependence and ecology of plant-microbial symbioses and phylogenetic comparative methods to study their evolutionary history.

Selected publications

Werner, G.D.A., Cornwell, W.K., Sprent, J.I., Kattge, J. Kiers, E.T. (2014). A single evolutionary innovation drives the deep evolution of symbiotic N2-fixation in angiosperms. Nature Communications. 5: 4087 PDF link   Article link

Werner, G.D.A., Kiers, E.T. (2015). Order of arrival structures arbuscular mycorrhizal colonisation of plants. New Phytologist. 205: 1515-1524 PDF link   Article link

Werner, G.D.A., Cornwell, W.K., Cornelissen, J.H.C., Kiers, E.T. (2015). Evolutionary signals of symbiotic persistence in the legume–rhizobia mutualism. Proc. Natl. Acad. Sci. USA. 112: 10262-10269 PDF link   Article link

Eusociality Evolution

Eusociality is an extraordinary form of cooperation, found in many social insects. Different ‘castes’ of workers divide labour and each perform highly specialised tasks, with workers foregoing reproduction to help the queen reproduce. This is an evolutionary puzzle because why would workers give up having own offspring, thereby seemingly reducing their own evolutionary success?

I use novel phylogenetic comparative methods and large-scale databases and phylogenies to study the evolution of eusociality in insects. I am interested in finding the traits and (environmental) factors that drive the transition towards this exceptionally succesful lifestyle.

 

Phylogenetic Comparative Methods

I use and develop novel phylogenetic comparative approaches to track the evolutionary history of (mutualistic) cooperation through time. I am particularly interested in using comparative methods to detect the evolutionary signal of pre-adaptations favouring the evolution of complex traits such as mutualisms and symbiosis. I also work on comparative methods to incorporate uncertainty in underlying (binary) trait data in comparative analyses, and have recently co-authored the new R-package sensiPhy (available on CRAN) to perform sensitivity analyses in phylogenetic comparative methods.

Selected publications

Werner, G.D.A., Cornwell, W.K., Sprent, J.I., Kattge, J. Kiers, E.T. (2014). A single evolutionary innovation drives the deep evolution of symbiotic N2-fixation in angiosperms. Nature Communications. 5: 4087 PDF link   Article link

Werner, G.D.A., Cornwell, W.K., Cornelissen, J.H.C., Kiers, E.T. (2015). Evolutionary signals of symbiotic persistence in the legume–rhizobia mutualism. Proc. Natl. Acad. Sci. USA. 112: 10262-10269 PDF link   Article link

Biological Markets

I am interested in the mechanisms that can stabilise cooperation in nature. In the absence of such mechanisms, over time, cooperation is undermined because cheaters that do not contribute to the interaction can outcompete cooperators.

If an individual can detect the quality of a potential partner, and reward more cooperative partners (or sanction low-quality partners) this can stabilise cooperation. Such behaviour can even lead to dynamics comparable to human economics, where resources and services are exchanged on a ‘biological market’.

I study how rewards and biological markets can help explain stability of (mutualistic) cooperation, specifically of cooperative interactions involving microbes.

Selected publications

Werner, G.D.A., Strassmann , J.E., Ivens, A.B.F., Engelmoer, D.J.P., Verbruggen, E., Queller, D.C., Noë, R., Johnson, N.C., Hammerstein, P., Kiers, E.T. (2014). Evolution of Microbial Markets. Proc. Natl. Acad. Sci. USA, 111(4): 1237–1244 PDF link   Article link

Werner, G.D.A., Kiers, E.T. (2015). Partner selection in the mycorrhizal mutualism. New Phytologist. 205: 1437–1442 PDF link   Article link

 

Evolutionary Game Theory

We can use game theory, a set of approaches and methods originating from the study of human social interactions, to study how social interactions in biology evolve. I use evolutionary game theory to study the evolution of specialisation and divisions of labour in symbioses.