Doomed by your partner: when mutualistic interactions are like an evolutionary millstone around a species’ neck

The global decline of mutualists such as pollinators and seed dispersers may cause negative direct and indirect impacts on biodiversity. Mutualistic network models used to understand the stability of mutualistic systems indicate that species with low partner diversity are most vulnerable to coextinction following mutualism disruption. However, existing models have not considered how species vary in their dependence on mutualistic interactions for reproduction or survival, overlooking the potential influence of this variation on species' coextinction vulnerability and on network stability. Using global databases and field experiments focused on the seed dispersal mutualism, we found that plants and animals that depend heavily on mutualistic interactions have higher partner diversity. Under simulated network disruption, this empirical relationship strongly reduced coextinction because the species most likely to lose mutualists depend least on their mutualists. The pattern also reduced the importance of network structure for stability; nested network structure had little effect on coextinction after simulations incorporated the empirically derived relationship between partner diversity and mutualistic dependence. Our results highlight a previously unknown source of stability in mutualistic networks and suggest that differences among species in their mutualistic strategy, rather than network structure, primarily accounts for stability in mutualistic communities.

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Ant association facilitates the evolution of diet breadth in a lycaenid butterfly

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2010.1959 ◽

2010 ◽

Vol 278 (1711) ◽

pp. 1539-1547 ◽

Cited By ~ 29

Author(s):

Matthew L. Forister ◽

Zachariah Gompert ◽

Chris C. Nice ◽

Glen W. Forister ◽

James A. Fordyce

Keyword(s):

Host Range ◽

Diet Breadth ◽

Demographic Model ◽

Adaptive Diversification ◽

Host Range Evolution ◽

Mutualistic Interactions ◽

Novel Host ◽

Lycaenid Butterfly ◽

Ant Association

The role of mutualistic interactions in adaptive diversification has not been thoroughly examined. Lycaenid butterflies provide excellent systems for exploring mutualistic interactions, as more than half of this family is known to use ants as a resource in interactions that range from parasitism to mutualism. We investigate the hypothesis that protection from predators offered to caterpillars by ants might facilitate host-range evolution. Specifically, experiments with the butterfly Lycaeides melissa investigated the role of ant association in the use of a novel host, alfalfa, Medicago sativa , which is a sub-optimal host for larval development. Survival on alfalfa is increased by the presence of ants, thus supporting the hypothesis that interaction with ants might be important for host-range evolution. Using a demographic model to explore ecological conditions associated with host-range expansion in L. melissa , we conclude that the presence of ants might be an essential component for populations persisting on the novel, sub-optimal host.

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Adaptive Diversification Due to Cooperative Interactions

Adaptive Diversification (MPB-48) ◽

10.23943/princeton/9780691128931.003.0006 ◽

2011 ◽

Author(s):

Michael Doebeli

Keyword(s):

Public Good ◽

Adaptive Diversification ◽

Cooperative Interactions ◽

Theoretical Literature ◽

Mutualistic Interactions ◽

Maintenance Of Diversity

This chapter focuses on adaptive diversification due to cooperative interactions. If predation has received less attention than competition as a cause for the origin and maintenance of diversity, mutualistic interactions have fared even worse. There is quite a substantial theoretical literature on the ecology of mutualistic interactions, but only a few studies have investigated mutualism as a potential driver of diversification. There is of course a rather huge literature on the evolution of intraspecific cooperation, and many of these models implicitly address the problem of coexistence between cheaters and cooperators, and hence the maintenance of diversity. However, the origin of diversity in cooperative contributions has only recently been investigated. Most models of cooperation assume that cooperators make a costly contribution to a public good, which is then distributed among certain members of the population.

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Move Over, Bacteria! Viruses Make Their Mark as Mutualistic Microbial Symbionts

Journal of Virology ◽

10.1128/jvi.02974-14 ◽

2015 ◽

Vol 89 (13) ◽

pp. 6532-6535 ◽

Cited By ~ 50

Author(s):

Marilyn J. Roossinck

Keyword(s):

Virus Discovery ◽

Mutualistic Interactions ◽

Microbial Symbionts

Viruses are being redefined as more than just pathogens. They are also critical symbiotic partners in the health of their hosts. In some cases, viruses have fused with their hosts in symbiogenetic relationships. Mutualistic interactions are found in plant, insect, and mammalian viruses, as well as with eukaryotic and prokaryotic microbes, and some interactions involve multiple players of the holobiont. With increased virus discovery, more mutualistic interactions are being described and more will undoubtedly be discovered.

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