Host shift and cospeciation rate estimation from co‐phylogenies

Abstract

Host shifts can cause novel infectious diseases, and is a key process in diversification. Disentangling the effects of host shift vs. those of cospeciation is non-trivial as both can result in phylogenic congruence. We develop a new framework based on network analysis and Approximate Bayesian Computation to quantify host shift and cospeciation rates in host-parasite systems. Our method enables estimation of the expected time to the next host shift or cospeciation event. We then apply it to avian haemosporidian parasite systems and to the pocket gophers-chewing lice system, and demonstrate that both host shift and cospeciation can be reliably estimated by our method. We confirm that host shifts have shaped the evolutionary history of avian haemosporidian parasites and have played a minor role in the gopher-chewing lice system. Our method is promising for predicting the rate of potential host shifts and thus the emergence of novel infectious diseases.

Inferring processes of coevolutionary diversification in a community of Panamanian strangler figs and associated pollinating wasps*

“…; Alcala et al. ). Although ABC is likelihood free and can be sensitive to choice of summary statistics for approximating the posterior probability (Robert et al.…”

“…In addition, the ABC event‐based method of Alcala et al. () allows symbiont lineages to be associated with multiple host lineages, modeling symbiont taxa as either a specialist or generalist based on the observed distribution of generalists in the data set.…”

Tree shape‐based approaches for the comparative study of cophylogeny

“…The basic premise of ABC is that fitting can proceed by adjusting the parameters of the model until it yields simulations that resemble the observed data. In another recent paper, Alcala, Jenkins, Christe, and Vuilleumier (2017) applied multiple network statistics (e.g., degree size) to simulated tanglegrams to estimate host switching and cospeciation rates using a rejection ABC method. Baudet et al (2014) recently used an ABC approach to cophylogeny using forward-time simulation of pathogen trees on a fixed host phylogeny, and employed a single distance measure based on the number of tip labels shared between the largest isomorphic subtrees.…”

Louse flies of Eleonora’s falcons that also feed on their prey are evolutionary dead‐end hosts for blood parasites

“…However, the insect vectors of these avian parasites exhibit relatively opportunistic behaviour by feeding on the blood of different bird species, which could lead to host switching. Indeed, host shifts are frequent, rapid processes that have shaped the evolutionary history of avian haemosporidians (Alcala, Jenkins, Christe, & Vuilleumier, ; Ricklefs et al, ). Bird‐parasite interactions have been intensively studied in order to identify specificity among avian haemosporidians and different hosts (Clark, Clegg, & Lima, ; Križanauskienė et al, ; Palinauskas, Valkiūnas, Bolshakov, & Bensch, ; Valkiūnas, ); however, very little attention has been paid to the occurrence of vector shifts, and, in general, to the role of vector feeding behaviour in facilitating or inhibiting host shifts (Gager et al, ; Ishtiaq et al, ; Kim & Tsuda, ).…”