Publications

For the most up-to-date list of my publications, please check my Google Scholar page.

I am always happy to share my work, so please contact me if you have any difficulties accessing my papers.

Research papers

Social Interactions in Viruses

• Multipartite viruses
  • Some viruses have evolved split genomes, in which the viral genome is encapsidated across multiple segments, each of which must reach a host independently for a successful infection. Despite the clear costs, this ‘multipartite’ lifestyle has evolved multiple times, and accounts for nearly 20% of known plant viral species. Existing explanations have relied on group-level benefits, which cannot realistically be large enough to explain the widespread existence of multipartitism. We showed that evolutionary cheating can provide an answer: multipartitism can arise from the sequential invasion of different types of viral cheat. This mechanism does not require a group benefit, and hence can explain multipartitism under realistic conditions, including the transition to highly multipartite viruses with more than two genome segments.
  • Leeks, A., Young, P.G., Turner, P.E., Wild, G. & West, S.A. 2023. Cheating leads to the evolution of multipartite viruses. PLOS Biology 21: e3002092.

• Collective infectious units
  • Many viruses disperse as groups, inside ‘collective infectious units’. Although these structures appear across many different viruses, there are few ideas for why they are favoured over individual transmission. We modelled some evolutionary hypotheses that could drive the evolution of collective infectious units.
  • Leeks, A., Sanjuán, R. & West, S.A. 2019. The evolution of collective infectious units in viruses. Virus Research 265: 94–101.

• Beneficial coinfection
  • Many viral infections show high levels of diversity, with many different variants of the same virus coexisting inside a host. This diversity presents an evolutionary problem: why don’t the faster-growing variants out-compete the slower-growing variants? We showed that diversity can be maintained if host cells infected by multiple different variants are more productive than cells infected by just one variant, a phenomenon that could be relatively common in RNA viruses.
  • Leeks, A., Segredo-Otero, E.A., Sanjuán, R. & West, S.A. 2018. Beneficial coinfection can promote within-host viral diversity. Virus Evol 4.

Theory of Mutualisms

• Transmission & relatedness
  • Symbionts that transmit vertically (from parent to offspring) generally provide more help to their host than those that transmit horizontally (from adult host to adult host). Two main explanations have been proposed for this: firstly, vertical transmission aligns the fitness interests of host and symbiont; secondly, vertical transmission reduces mixing of symbiont lineages, increasing the genetic relatedness between symbionts sharing a host. We built a model in which both mechanisms could operate, and we showed that the second mechanism tends to overshadow the first mechanism.
  • Leeks, A., dos Santos, M. & West, S.A. 2019. Transmission, relatedness, and the evolution of cooperative symbionts. J Evol Biol jeb.13505.

Review Papers

• Open questions in the social lives of viruses
  • Social interactions are critical for understanding viruses. At the same time, viruses can challenge existing ideas within social evolution, sometimes requiring new kinds of theoretical explanation. We wrote this paper to highlight these opportunities, focusing on conceptual advances that could arise through studying the evolution of viral social interactions. We describe the ways in which viruses can be social, we discuss five key unsolved conceptual questions, and we suggest the types of theoretical and empirical work that could be useful for driving the field forward.
  • Leeks, A., Bono, L.M., Ampolini, E.A., Souza, L.S., Höfler, T., Mattson, C.L., Dye, A.E., & Díaz-Muñoz, S.L. 2023. Open questions in the social lives of viruses. Journal of Evolutionary Biology 36: 1551–1567.
  • This paper was an invited review following our Social Lives of Viruses meeting in 2022, and emerged from discussions among early career researchers who attended the meeting. Our paper was released alongside six invited commentaries by others in the field; brief summaries and links to each of the associated commentaries can be found here.

• The evolution of cheating in viruses
  • Often, the best way to see viral sociality is when it breaks down. This happens when viral cheats emerge; these are molecular parasites that exploit other viruses. Some viral cheats are familiar and have long been studied within virology. For example: defective interfering genomes are deletion mutants that arise in most known viruses, and spread by parasitising shared gene products in coinfection; satellite viruses similarly exploit wild-type viruses, and have long been known to determine plant virus pathogenicity and influence human health. In this paper, we used the evolutionary concept of cheating to define these and other viral parasites, highlighting the common evolutionary threads that link these otherwise disparate viral entities. We show how to formally test for cheating in viruses, we survey the diversity of known viral cheats, and we discuss the opportunities that studying viral cheats could unlock for both virology and evolutionary biology.
  • Leeks, A., West, S.A. & Ghoul, M. 2021. The evolution of cheating in viruses. Nature Communications. 12: 6928.

Commentaries

• Altruism in a virus
  • We wrote a short commentary on Domingo-Calap et al’s work showing that viral suppression of interferon release from infected cells is costly to individual viruses, but provides a group benefit. Consequently, we can understand why viruses have evolved to suppress interferon by applying the evolutionary concept of altruism.
  • Leeks, A. & West, S.A. 2019. Altruism in a virus. Nat Microbiol 4: 910–911.

Thesis

My doctoral thesis is freely available here. The introduction and conclusion are otherwise unpublished and contain some commentary on the links between social evolution theory and virology.