A need to consider the evolutionary genetics of host–symbiont mutualisms

• Published in: Journal of evolutionary biology Vol. 33; no. 12; pp. 1656 - 1668
• Main Authors: Stoy, Kayla S., Gibson, Amanda K., Gerardo, Nicole M., Morran, Levi T.
• Format: Journal Article
• Language: English
• Published: Switzerland Blackwell Publishing Ltd 01-12-2020
• Subjects: Animals; Biological Coevolution - genetics; Evolution; Evolutionary genetics; Gene Transfer, Horizontal; Genetic diversity; Genetic Variation; Genetics; horizontal transmission; Host-Parasite Interactions - genetics; Models, Genetic; mutualism; Recombination, Genetic; sexual recombination; Symbiosis; Symbiosis - genetics; sexual recombination; horizontal transmission; symbiosis; evolutionary genetics; mutualism
• ISSN: 1010-061X; 1420-9101
• DOI: 10.1111/jeb.13715

Despite the ubiquity and importance of mutualistic interactions, we know little about the evolutionary genetics underlying their long‐term persistence. As in antagonistic interactions, mutualistic symbioses are characterized by substantial levels of phenotypic and genetic diversity. In contrast to antagonistic interactions, however, we, by and large, do not understand how this variation arises, how it is maintained, nor its implications for future evolutionary change. Currently, we rely on phenotypic models to address the persistence of mutualistic symbioses, but the success of an interaction almost certainly depends heavily on genetic interactions. In this review, we argue that evolutionary genetic models could provide a framework for understanding the causes and consequences of diversity and why selection may favour processes that maintain variation in mutualistic interactions.
Many mutualisms are characterized by phenotypic and genetic variation. The implications of this variation for the long‐term persistence of host‐symbiont mutualisms remains unknown.