More Like this

1. How does host social behavior drive parasite non-selective evolution from the within-host to the landscape-scale?

   https://doi.org/10.1007/s00265-021-03089-y  

   Janecka, Mary J. ; Rovenolt, Faith ; Stephenson, Jessica F. ( November 2021 , Behavioral Ecology and Sociobiology)

   Social interactions with conspecifics are key to the fitness of most animals and, through the transmission opportunities they provide, are also key to the fitness of their parasites. As a result, research to date has largely focused on the role of host social behavior in imposing selection on parasites, particularly their virulence and transmission phenotypes. However, host social behavior also influences the distribution of parasites among hosts, with implications for their evolution through non-random mating, gene flow, and genetic drift, and thus ability to respond to that selection. Here, we review the paucity of empirical studies on parasites, and draw from empirical studies of free-living organisms and population genetic theory to propose several mechanisms by which host social behavior potentially drives parasite evolution through these less-well studied mechanisms. We focus on the guppy host and Gyrodactylus (Monogenea) ectoparasitic flatworm system and follow a spatially hierarchical outline to highlight that social behavior varies between individuals, and between host populations across the landscape, generating a mosaic of ecological and evolutionary outcomes for their infecting parasites. We argue that the guppy-Gyrodactylus system presents a unique opportunity to address this fundamental knowledge gap in our understanding of the connection between host social behavior and parasite evolution. Individual differences in host social behavior generates fine-scale changes in the spatial distribution of parasite genotypes, shape the size, and diversity of their infecting parasite populations and may generate non-random mating on, and non-random transmission between hosts. While at population and metapopulation level, variation in host social behavior interacts with landscape structure to affect parasite gene flow, effective population size, and genetic drift to alter the coevolutionary potential of local adaptation. 

   more » « less
2. Range expansion in an introduced social parasite-host species pair

   https://doi.org/10.1007/s10530-019-02011-y  

   Helms, Jackson A. ; Ijelu, Selassie E. ; Haddad, Nick M. ( August 2019 , Biological Invasions)
3. Collective decision‐making when quantity is more important than quality: Lessons from a kidnapping social parasite

   https://doi.org/10.1111/1365-2656.13423  

   Miller, Julie S. ; Dussutour, ed., Audrey ( January 2021 , Journal of Animal Ecology)

   Identifying the general principles that shape mechanisms of collective decision‐making requires studies that span a diversity of ecological contexts. However, collective decision‐making has only been explored in a handful of systems.

   Here, I investigate the ecologically mediated costs and benefits of collective decisions by socially parasitic kidnapping antsTemnothorax americanusover where to launch raids to steal host brood.

   I first investigate their sampling strategies and preferences with choice tests. Using more realistic spatial scales, I confirm the findings of others that colonies use a sequential choice strategy, and do not compare options simultaneously. I then ask which ecological conditions could favour the evolution of this strategy by testing the following hypotheses from optimal foraging and mate choice theories: (a) raiding decisions are time constrained or (b) search payoffs are low due to resource uniformity.

   Spatial distribution and phenological data on nest contents support the time constraints hypothesis. Host nests contain an optimal ratio of brood and workers for a brief period relative to discovery rates. Colonies therefore benefit from raiding most nests they find in this period rather than deliberating over the best choice, favouring host quantity over quality.

   The decision strategy for raids uncovered here contrasts with best‐of‐n collective decision‐making found in other systems. These findings demonstrate that ecological constraints on information acquisition can alter how collectives process information.

    

   more » « less
4. Trematode Clone Abundance Distributions: An Eco-Evolutionary Link between Parasite Transmission and Parasite Mating Systems

   https://doi.org/10.1645/22-68  

   Criscione, Charles D. ; Hulke, Jenna M. ; Goater, Cameron P. ( December 2022 , Journal of Parasitology)
5. A reconstruction of parasite burden reveals one century of climate-associated parasite decline

   https://doi.org/10.1073/pnas.2211903120  

   Wood, Chelsea L. ; Welicky, Rachel L. ; Preisser, Whitney C. ; Leslie, Katie L. ; Mastick, Natalie ; Greene, Correigh ; Maslenikov, Katherine P. ; Tornabene, Luke ; Kinsella, John M. ; Essington, Timothy E. ( January 2023 , Proceedings of the National Academy of Sciences)

   Long-term data allow ecologists to assess trajectories of population abundance. Without this context, it is impossible to know whether a taxon is thriving or declining to extinction. For parasites of wildlife, there are few long-term data—a gap that creates an impediment to managing parasite biodiversity and infectious threats in a changing world. We produced a century-scale time series of metazoan parasite abundance and used it to test whether parasitism is changing in Puget Sound, United States, and, if so, why. We performed parasitological dissection of fluid-preserved specimens held in natural history collections for eight fish species collected between 1880 and 2019. We found that parasite taxa using three or more obligately required host species—a group that comprised 52% of the parasite taxa we detected—declined in abundance at a rate of 10.9% per decade, whereas no change in abundance was detected for parasites using one or two obligately required host species. We tested several potential mechanisms for the decline in 3+-host parasites and found that parasite abundance was negatively correlated with sea surface temperature, diminishing at a rate of 38% for every 1 °C increase. Although the temperature effect was strong, it did not explain all variability in parasite burden, suggesting that other factors may also have contributed to the long-term declines we observed. These data document one century of climate-associated parasite decline in Puget Sound—a massive loss of biodiversity, undetected until now. 

   more » « less