Indirect effects drive coevolution in mutualistic networks
An approach to ecological interactions that integrates coevolutionary dynamics and network structure, showing that selection in mutualisms is shaped not only by the mutualistic partners but by all sorts of indirect effects from other species in the network. Untangling the bank In the final pages of...
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Published in | Nature (London) Vol. 550; no. 7677; pp. 511 - 514 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
26.10.2017
Nature Publishing Group |
Subjects | |
Online Access | Get full text |
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Summary: | An approach to ecological interactions that integrates coevolutionary dynamics and network structure, showing that selection in mutualisms is shaped not only by the mutualistic partners but by all sorts of indirect effects from other species in the network.
Untangling the bank
In the final pages of
The Origin of Species
, Charles Darwin presented the image of a tangled bank to evoke the constant interplay of plants and animals in an ecosystem. As each individual struggles to survive and reproduce, its efforts affect the whole ecosystem. It is a beautiful image, but much remains to be learned about the details of such effects. The selective pressures that shape intimate mutualisms between a plant and a specialist pollinator, for example, or the general behaviour of ecological networks, are well known, but less is understood about how selective pressures at various levels ripple through networks. Here, the authors integrate coevolutionary dynamics and network structure to show that selection in mutualisms is shaped not only by the mutualistic partners but by all sorts of indirect effects rippling across the tangled bank.
Ecological interactions have been acknowledged to play a key role in shaping biodiversity
1
,
2
. Yet a major challenge for evolutionary biology is to understand the role of ecological interactions in shaping trait evolution when progressing from pairs of interacting species to multispecies interaction networks
2
. Here we introduce an approach that integrates coevolutionary dynamics and network structure. Our results show that non-interacting species can be as important as directly interacting species in shaping coevolution within mutualistic assemblages. The contribution of indirect effects differs among types of mutualism. Indirect effects are more likely to predominate in nested, species-rich networks formed by multiple-partner mutualisms, such as pollination or seed dispersal by animals, than in small and modular networks formed by intimate mutualisms, such as those between host plants and their protective ants. Coevolutionary pathways of indirect effects favour ongoing trait evolution by promoting slow but continuous reorganization of the adaptive landscape of mutualistic partners under changing environments. Our results show that coevolution can be a major process shaping species traits throughout ecological networks. These findings expand our understanding of how evolution driven by interactions occurs through the interplay of selection pressures moving along multiple direct and indirect pathways. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0028-0836 1476-4687 |
DOI: | 10.1038/nature24273 |