How specialists can be generalists: resolving the "parasite paradox" and implications for emerging infectious disease

Hymenolepis folkertsi n. sp. (Eucestoda: Hymenolepididae) in the oldfield mouse Peromyscus polionotus (Wagner) (Rodentia: Cricetidae: Neotominae) from the southeastern Nearctic with comments on tapeworm faunal diversity among deer mice

“…Geographic and host distribution suggests that diversification among species of Hymenolepis has been linked to colonization of unrelated taxa of Muroidea and other Rodentia during the process of host radiation. Furthermore, ecological similarity of some rodents, chiropterans, and soricomorphs is consistent with the possibility of mutual exchanges of these helminths between phylogenetically distinct groups of small mammals, supporting current ideas about the importance of host switching and ecological fitting in diversification of complex faunas (e.g., Hoberg and Brooks 2008;Agosta et al 2010;Brooks et al 2014).…”

Finding Them Before They Find Us: Informatics, Parasites, and Environments in Accelerating Climate Change

“…At this time, there is growing interest in parasites as we begin to understand more and more that there are direct connections among climate change, biodiversity dynamics, and emerging infectious disease (EID). Parasites occupy a central role in efforts to develop proactive protocols for monitoring changes in ecosystem structure and for detecting the potential for emerging disease in resident and colonizing host species, be they human, livestock, or wildlife (Daszak et al, 2000;Brooks and Hoberg, 2006, 2008Patz et al, 2008;Agosta et al, 2010;Hoberg, 2010;Weaver et al, 2010;Hartigan et al, 2012;Altizer et al, 2013;Hoberg and Brooks, 2013). Parasites, especially those with specialized transmission dynamics, including complex life cycles, are not only agents of disease in humans, food-animal resources, crops, and wildlife, they are also powerful representations of the ecological and historical context of the diseases they cause (Dobson and Hudson, 1986;Dobson and May, 1986a, b;Dobson and Carper, 1992;Hoberg, 1997;Dobson and Foufopoulos, 2001;Marcogliese, 2001Marcogliese, , 2005Nieberding and Olivieri, 2007;Hoberg and Brooks, 2008;Rosenthal, 2008;Lafferty, 2009;Kilpatrick, 2011;Kuris, 2012).…”

“…Such an ecocentric view of parasite diversification, tied to considerable complexity in ecological processes, counters more than a century of coevolutionary thinking about the nature of the development of host-parasite assemblages (for comprehensive reviews, see Brooks andMcLennan, 1993, 2002;Janz, 2011). Further, the apparent significance of host colonization in diversification poses a ''parasite paradox'' (Agosta et al, 2010) that stems from 2 observations: (1) Parasites demonstrate specificity (restricted and apparently specialized host ranges) and are resource specialists; and (2) such specialization occurs even though shifts onto relatively unrelated hosts are common in the phylogenetic diversification of parasite lineages and are even often directly observable in ecological time.…”

“…The articulation of what we herein refer to as the ''Stockholm paradigm'' serves as a conceptual foundation for resolution of the parasite paradox and provides a new integrative view of complex associations grounded in both a considerable body of experimental observations and in core principles emanating from 4 academic generations of researchers at Stockholm University (for a review, see Brooks and McLennan, 2002;Agosta et al, 2010;Janz, 2011, and references therein). In this paradigm, the resolution of the parasite paradox emerges through integration of 4 key ecological and historical concepts: ecological fitting; the oscillation hypothesis; the geographic mosaic theory of coevolution; and taxon pulses.…”

Similarities among ectoparasite fauna of sigmodontine rodents: phylogenetic and geographical influences

“…Thus, ecological fitting is a process whereby organisms colonize and persist in novel environments, use novel resources or form novel associations with other species (Agosta and Klemens, 2008). In this process, the colonization of novel hosts occurs because the parasite has pre-adaptations due to the new host sharing important characteristics with the current host or this adaptation may be the result of the parasite's phenotypic plasticity (Agosta et al 2010). Thus, the similarities between the parasite faunas of host species may be determined largely by their morphological, physiological, and/or environmental similarities, which are unrelated to phylogeny and, in some cases, may be due to convergence.…”