Effect of host-switching on the eco-evolutionary patterns of parasites

Increasing empirical evidence has revealed that host-switching is more common than cospeciation in the history of parasites. Here, we investigated how the intensity of host-switching, mediated by opportunity and compatibility, affects the phylogenetic history and ecology of the parasites. We developed a theoretical model to simulate the evolution of populations of parasites that can explore and colonize new hosts under variable host-switching intensities. Eco-evolutionary patterns (beta diversity/normalized Sackin index) obtained from parasite simulations were compared to nine empirical cases. Our model reproduced the empirical patterns, and such simulations varied in host-switching intensity according to the analysed case. This intensity does not differ among cases of ecto and endoparasites, but it was stronger in local cases when compared to a regional scale. Our results highlight the importance of contact opportunity, and suggest that host-switching intensity mediates the exploration and colonization of new hosts promoting variation in the eco-evolutionary patterns. Key-words: dispersion of parasites, opportunity and compatibility of interaction, phylogenetic conservatism and structure of community of parasites.

A Comparative Study of Plasma Proteins from Twenty-Nine Species of Albatrosses And Petrels (Order Procellariiformes)

<p>The plasma proteins of 29 species of albatrosses and petrels were electrophoretically separated in acrylamide gels to clarify relationships at the species-group to family-group levels. Little in the resulting data from 472 birds seriously contests the present classification of the Procellariiformes; much of the biochemical evidence supports, confirms, and clarifies the proposals of conventional taxonomic methodology. The biochemical data give fresh insights into the interrelationships of procellariiform taxa, and highlight intriguing new problems. Sex, season, age, and other sources of non-genetic protein variation are insignificant for taxonomic purposes. Proteins of comparable value include the transferrins, some α and β globulins, albumins, prealbumins, and non-specific esterases. Genetic variations in the mobility of these proteins are useful at the genus-group level and below. Other proteins are monomorphic at genus and family level, and three are monomorphic in both number and mobility throughout the Procellariiformes; these are useful reference points for calibrating samples on different gels. One conspicuous α protein is absent in the Hydrobatidae but present in all other families; the implications of this are discussed. Polymorphic proteins at the population or species level were not detected; this conspicuous phylogenetic conservatism is discussed with regard to its possible evolutionary significance. Following a summary of the protein data; three categories of, defined probability statements, based on the biochemical and other evidence, allow speculative comment on the evolutionary relationships and history of the taxa within the Procellariiformes. The value of further biochemical research into the marine birds is emphasised.</p>

A Comparative Study of Plasma Proteins from Twenty-Nine Species of Albatrosses And Petrels (Order Procellariiformes)

<p>The plasma proteins of 29 species of albatrosses and petrels were electrophoretically separated in acrylamide gels to clarify relationships at the species-group to family-group levels. Little in the resulting data from 472 birds seriously contests the present classification of the Procellariiformes; much of the biochemical evidence supports, confirms, and clarifies the proposals of conventional taxonomic methodology. The biochemical data give fresh insights into the interrelationships of procellariiform taxa, and highlight intriguing new problems. Sex, season, age, and other sources of non-genetic protein variation are insignificant for taxonomic purposes. Proteins of comparable value include the transferrins, some α and β globulins, albumins, prealbumins, and non-specific esterases. Genetic variations in the mobility of these proteins are useful at the genus-group level and below. Other proteins are monomorphic at genus and family level, and three are monomorphic in both number and mobility throughout the Procellariiformes; these are useful reference points for calibrating samples on different gels. One conspicuous α protein is absent in the Hydrobatidae but present in all other families; the implications of this are discussed. Polymorphic proteins at the population or species level were not detected; this conspicuous phylogenetic conservatism is discussed with regard to its possible evolutionary significance. Following a summary of the protein data; three categories of, defined probability statements, based on the biochemical and other evidence, allow speculative comment on the evolutionary relationships and history of the taxa within the Procellariiformes. The value of further biochemical research into the marine birds is emphasised.</p>

Phylogenetic dependence of plant-soil feedback promotes rare species in a subtropical forest

The widespread observation that rare species have stronger conspecific plant-soil feedback (PSF) than common species raises more questions than answers on how rare species can possibly win the dance with abundant species. Here, we test soil feedback effect of phylogenetically related species on seedlings of contrasting local abundance in a subtropical forest. The results showed that although rare species suffered strong negative PSF in soils of conspecifics or phylogenetically close relatives, no such feedback was found in the soils of distant relatives. In contrast, although common species had weak conspecific PSF, they suffered consistently strong heterospecific soil feedback. These mechanisms ensure that rare species would fare well in the neighborhood of phylogenetically distant heterospecifics but do poorly under their close relatives, while common species perform relatively well in their own neighborhood but poorly in others’. This phylogenetic conservatism in PSF facilitates the persistence of rare species in a community.

Phylogenetic conservatism drives nutrient dynamics of coral reef fishes

The relative importance of evolutionary history and ecology for traits that drive ecosystem processes is poorly understood. Consumers are essential drivers of nutrient cycling on coral reefs, and thus ecosystem productivity. We use nine consumer “chemical traits” associated with nutrient cycling, collected from 1,572 individual coral reef fishes (178 species spanning 41 families) in two biogeographic regions, the Caribbean and Polynesia, to quantify the relative importance of phylogenetic history and ecological context as drivers of chemical trait variation on coral reefs. We find: (1) phylogenetic relatedness is the best predictor of all chemical traits, substantially outweighing the importance of ecological factors thought to be key drivers of these traits, (2) phylogenetic conservatism in chemical traits is greater in the Caribbean than Polynesia, where our data suggests that ecological forces have a greater influence on chemical trait variation, and (3) differences in chemical traits between regions can be explained by differences in nutrient limitation associated with the geologic context of our study locations. Our study provides multiple lines of evidence that phylogeny is a critical determinant of contemporary nutrient dynamics on coral reefs. More broadly our findings highlight the utility of evolutionary history to improve prediction in ecosystem ecology.

Advances in the Biology and Conservation of Turtles

The approximately 356 species of testudines (turtles) are remarkable for their blend of phylogenetic conservatism and diversity [...]