Analysis of parasite host-switching: limitations on the use of phylogenies

Parasitology ◽  
1999 ◽  
Vol 119 (S1) ◽  
pp. S111-S123 ◽  
Author(s):  
J. A. Jackson
Keyword(s):  
Host Species ◽  
Host Tree ◽  
Host Switching ◽  
Environmental Constraints ◽  
Important Process ◽  
Potential Host ◽  
Historical Reconstructions ◽  
History Of ◽  
Host Parasite ◽  
Parasite Assemblages

SUMMARYEven the most generalist parasites usually occur in only a subset of potential host species, a tendency which reflects overriding environmental constraints on their distributions in nature. The periodic shifting of these limitations represented by host-switches may have been an important process in the evolution of many host-parasite assemblages. To study such events, however, it must first be established where and when they have occurred. Past host-switches within a group of parasites are usually inferred from a comparison of the parasite phylogeny with that of the hosts. Congruence between the phylogenies is often attributed to a history of association by descent with cospeciation, and incongruence to host-switching or extinction in ‘duplicated’ parasite lineages (which diverged without a corresponding branching of the host tree). The inference of host-switching from incongrucnt patterns is discussed. Difficulties arise because incongruence can frequently be explained by different combinations of biologically distinct events whose relative probabilities are uncertain. Also, the models of host parasite relationships implicit in historical reconstructions may often not allow for plausible sources of incongruence other than host-switching or duplication/extinction, or for the possibility that colonization could, in some circumstances, be disguised by ‘false’ congruence.

Phylogeny Inferred From Allozymes in the Heterodoxus-Octoseriatus Group of Species (Phthiraptera, Boopiidae)

1992 ◽  
Vol 40 (4) ◽  
pp. 411 ◽  
Author(s):  
SC Barker ◽  
DA Briscoe ◽  
RL Close
Keyword(s):  
Phylogenetic Relationships ◽  
Morphological Characters ◽  
Host Switching ◽  
Phenetic Analysis ◽  
Geographic Ranges ◽  
History Of ◽  
Group A ◽  
Cladistic Analyses ◽  
Allozyme Loci ◽  
Host Parasite

Phenetic and phylogenetic relationships in the Heterodoxus octoseriatus group of species were explored with data from 21 putative allozyme loci. The phenetic analyses and some of the cladistic analyses (maximum parsimony) were consistent with a phenetic analysis of morphological characters in that they indicated two main lines of evolution in the H. octoseriatus group. These culminated in two groups of species: (i) H. harrisoni, H. hughendensis, H. closei, H. maynesi, H. octoseriatus, H. lesouefi, H. briscoei and H. insulatus, and (ii) H. murrayi, H. insularis and H. orarius. The allozyme and morphological analyses, however, differed in the arrangement of species within the two main groups. Other cladistic analyses revealed the first group of lice, but not the second group. A hypothesis proposed for the evolution of the H. octoseriatus group involves widespread host-switching followed by the expansion of the geographic ranges of some lice at the expense of others. The evolution of host-parasite associations among rock-wallabies and lice from the H. octoseriatus group demonstrates how tangled the history of host-parasite associations may become.

scholarly journals Phylogeny and biogeography of species of Syphacia Seurat, 1916 (Nemata : Oxyurida : Oxyuridae) from the Australian Bioregion

2016 ◽  
Vol 64 (2) ◽  
pp. 81 ◽  
Author(s):  
Haylee J. Weaver ◽  
Scott Monks ◽  
Scott L. Gardner
Keyword(s):  
Phylogenetic Analysis ◽  
Host Species ◽  
Morphological Characters ◽  
Global Distribution ◽  
Host Switching ◽  
Ecological Fitting ◽  
Host Evolution ◽  
Host Parasite

Pinworm nematodes of the genus Syphacia (Nemata : Oxyurida : Oxyuridae) have a global distribution, and infect the caecum of rodents. Within the Australian Bioregion, 17 species of Syphacia infect a range of rodent hosts. Pinworms are traditionally thought to have coevolutionary relationships with their hosts, but the evolution and dispersal of Australian rodents and their helminths remains unclear. This combination of factors allowed us to investigate the likely relationships of Australian Syphacia species based on phylogenetic analysis, overlaid with the ecology and relationships of host species. We conducted a phylogenetic analysis using morphological characters of the species of Syphacia from the Australian Bioregion in order to examine the relationships between species, and to investigate how host evolution and phylogeny could inform (or be informed) by parasite phylogeny. Application of the taxon pulse theory of parasite speciation by matching host species to parasites shed some light on the timing of speciation of rodent hosts. We found that species of Syphacia had reasonably close host–parasite relationships, with additional evidence for ecological fitting or host switching occurring. Evidence provided here suggests strongly that most elements of the Stockholm Paradigm are at play in structuring the relationships we observe in this pinworm–mammal system.

Coevolutionary patterns and diversification of avian malaria parasites in African sunbirds (Family Nectariniidae)

Parasitology ◽  
2014 ◽  
Vol 142 (5) ◽  
pp. 635-647 ◽  
Author(s):  
ELVIN J. LAURON ◽  
CLAIRE LOISEAU ◽  
RAURI C. K. BOWIE ◽  
GREG S. SPICER ◽  
THOMAS B. SMITH ◽  
...  
Keyword(s):  
Host Specificity ◽  
Avian Malaria ◽  
Malaria Parasites ◽  
Biogeographic History ◽  
History Of ◽  
Host Parasite ◽  
East West ◽  
Parasite Assemblages ◽  
Coevolutionary History ◽  
Avian Malaria Parasites

SUMMARYThe coevolutionary relationships between avian malaria parasites and their hosts influence the host specificity, geographical distribution and pathogenicity of these parasites. However, to understand fine scale coevolutionary host–parasite relationships, robust and widespread sampling from closely related hosts is needed. We thus sought to explore the coevolutionary history of avianPlasmodiumand the widespread African sunbirds, family Nectariniidae. These birds are distributed throughout Africa and occupy a variety of habitats. Considering the role that habitat plays in influencing host-specificity and the role that host-specificity plays in coevolutionary relationships, African sunbirds provide an exceptional model system to study the processes that govern the distribution and diversity of avian malaria. Here we evaluated the coevolutionary histories using a multi-gene phylogeny for Nectariniidae and avianPlasmodiumfound in Nectariniidae. We then assessed the host–parasite biogeography and the structuring of parasite assemblages. We recoveredPlasmodiumlineages concurrently in East, West, South and Island regions of Africa. However, severalPlasmodiumlineages were recovered exclusively within one respective region, despite being found in widely distributed hosts. In addition, we inferred the biogeographic history of these parasites and provide evidence supporting a model of biotic diversification in avianPlasmodiumof African sunbirds.

The function and evolution of aggressive host behavior towards the brown-headed cowbird (Molothrus ater)

1977 ◽  
Vol 55 (3) ◽  
pp. 508-518 ◽  
Author(s):  
Raleigh J. Robertson ◽  
Richard F. Norman
Keyword(s):  
Host Species ◽  
Molothrus Ater ◽  
Directional Selection ◽  
Selection Model ◽  
Low Density ◽  
Host Behavior ◽  
Positive Correlation ◽  
Potential Host ◽  
History Of ◽  
A Minor

Aggression to model brown-headed cowbirds measured at nests of 34 potential host species shows a positive correlation with rate of parasitism. The data are used to test two hypotheses: (1) that aggression functions as an antiparasite defense reducing parasitism, and (2) that cowbirds use host aggression as a cue when searching for nests.Our results suggest that host aggression only serves as an effective antiparasite defense in dense host populations. In low-density populations aggression is probably used as a nest-finding cue by cowbirds, because there are too few neighbouring hosts to mount an effective multispecies mobbing response. Although being aggressive is maladaptive in the latter situation, the evolution of increased aggressiveness is evident, because individuals breeding in dense populations have greater fitness. The adaptive complex is further complicated because host aggression may have a major innate component and a minor learned component.Experiments conducted on different host populations corroborate the hypothesis that hosts with the longer history of sympatry with cowbirds are more aggressive. These data are consistent with the predictions of a simple directional selection model for host aggression.

Juristische Wahrheit

2021 ◽  
Author(s):  
Falko Maxin
Keyword(s):  
19Th Century ◽  
Legal Theory ◽  
Social Knowledge ◽  
Important Process ◽  
Criminal Jurisdiction ◽  
Procedural Law ◽  
History Of ◽  
Theory Of Evidence ◽  
The 19Th Century

The mechanics of the "legal theory of evidence", which dominated German procedural law until the second half of the 19th century, was intended to render the truth of a circumstance to be proven calculable by means of legal rigour and arithmetic consistency. How can we explain in retrospect its seemingly abrupt replacement by the judge´s "free consideration of evidence" according to his subjective conviction as we know it today? Does this indicate something fundamental having changed in the nature and significance of the judge's knowledge of facts? Did a post-Kantian understanding of truth together with an altered conception of social knowledge play a role in this important process in the history of justice? By using the example of civil and criminal jurisdiction, this study examines these questions in its search for "legal truth" - and in doing so outlines a history of the theory of evidence in the 19th century.

Predicting the potential distribution ofVexillata(Nematoda: Ornithostrongylidae) and its hosts (Mammalia: Rodentia) within America

2012 ◽  
Vol 87 (4) ◽  
pp. 400-408 ◽  
Author(s):  
E.A. Martínez-Salazar ◽  
T. Escalante ◽  
M. Linaje ◽  
J. Falcón-Ordaz
Keyword(s):  
Environmental Factor ◽  
Species Distribution ◽  
Host Species ◽  
Potential Distribution ◽  
Species Distribution Modelling ◽  
Distribution Modelling ◽  
Distributional Patterns ◽  
Suitable Habitats ◽  
Temperature Seasonality ◽  
Host Parasite

AbstractSpecies distribution modelling has been a powerful tool to explore the potential distribution of parasites in wildlife, being the basis of studies on biogeography.Vexillataspp. are intestinal nematodes found in several species of mammalian hosts, such as rodents (Geomyoidea) and hares (Leporidae) in the Nearctic and northern Neotropical regions. In the present study, we modelled the potential distribution ofVexillataspp. and their hosts, using exclusively species from the Geomyidae and Heteromyidae families, in order to identify their distributional patterns. Bioclimatic and topographic variables were used to identify and predict suitable habitats forVexillataand its hosts. Using these models, we identified that temperature seasonality is a significant environmental factor that influences the distribution of the parasite genus and its host. In particular, the geographical distribution is estimated to be larger than that predicted for its hosts. This suggests that the nematode has the potential to extend its geographical range and also its spectrum of host species. Increasing sample size and geographical coverage will contribute to recommendations for conservation of this host–parasite system.

The effects of seasonality on host–bat fly ecological networks in a temperate mountain cave

Parasitology ◽  
2016 ◽  
Vol 144 (5) ◽  
pp. 692-697 ◽  
Author(s):  
KARINA D. RIVERA-GARCÍA ◽  
CÉSAR A. SANDOVAL-RUIZ ◽  
ROMEO A. SALDAÑA-VÁZQUEZ ◽  
JORGE E. SCHONDUBE
Keyword(s):  
Species Composition ◽  
Host Species ◽  
Rainy Season ◽  
Ecological Networks ◽  
Host Interactions ◽  
Bat Flies ◽  
Bat Fly ◽  
Low Prevalence ◽  
Host Parasite

SUMMARYChanges in the specialization of parasite–host interactions will be influenced by variations in host species composition. We evaluated this hypothesis by comparing the composition of bats and bat flies within a roost cave over one annual. Five bat and five bat fly species occupied the cave over the course of the study. Bat species composition was 40% different in the rainy season compared with the dry–cold and dry–warm seasons. Despite the incorporation of three new bat species into the cave during the rainy season, bat fly species composition was not affected by seasonality, since the bats that arrived in the rainy season only contributed one new bat fly species at a low prevalence. Bat–bat fly ecological networks were less specialized in the rainy season compared with the dry–cold and dry–warm seasons because of the increase of host overlap among bat fly species during this season. This study suggests that seasonality promote: (1) differences in host species composition, and (2) a reduction in the specialization of host–parasite ecological networks.

Host–parasite co-evolution

2021 ◽  
pp. 389-416
Author(s):  
Paul Schmid-Hempel
Keyword(s):  
Meiotic Recombination ◽  
Evolutionary Process ◽  
Host Switching ◽  
Response To Selection ◽  
Red Queen ◽  
Arms Races ◽  
Migration Rates ◽  
Frequency Changes ◽  
Host Parasite ◽  
Relative Migration

Macroevolutionary patterns concern phylogenies of hosts and their parasites. From those, co-speciation occurs; but host switching is a common evolutionary process and more likely when hosts are close phylogenetically and geographical ranges overlap. Microevolutionary processes refer to allele frequency changes within population. In arms races, traits of hosts and parasites evolve in one direction in response to selection by the other party. With selective sweeps, advantageous alleles rapidly spread in host or parasite population and can become fixed. With antagonistic negative frequency-dependent fluctuations (Red Queen dynamics) genetic polymorphism in populations can be maintained, even through speciation events. A Red Queen co-evolutionary process can favour sexual over asexual reproduction and maintain meiotic recombination despite its other disadvantages (two-fold cost of sex). Local adaptation of host and parasites exist in various combinations; the relative migration rates of the two parties, embedded in a geographical mosaic, are important for this process.

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