9 research outputs found
The role of sex separation in neutral speciation
Neutral speciation mechanisms based on isolation by distance and sexual
selection, termed topopatric, have recently been shown to describe the observed
patterns of abundance distributions and species-area relationships. Previous
works have considered this type of process only in the context of hermaphrodic
populations. In this work we extend a hermaphroditic model of topopatric
speciation to populations where individuals are explicitly separated into males
and females. We show that for a particular carrying capacity speciation occurs
under similar conditions, but the number of species generated decreases as
compared to the hermaphroditic case. Evolution results in fewer species having
more abundant populations.Comment: 18 pages + 8 figure
The species-area relationship in centipedes (Myriapoda: Chilopoda): a comparison between Mediterranean island groups
The present study article examines the shapes of centipede species–area relationships (SARs) in the Mediterranean islands, compares the results of the linear form of the power model between archipelagos, discusses biological significance of the power model parameters with other taxa on the Aegean archipelago, and tests for a significant small-island effect (SIE). We used 11 models to test the SARs and we compared the quality-of-fit of all candidate models. The power function ranked first and Z-values was in the range 0.106–0.334. We assessed the presence of SIEs by fitting both a continuous and discontinuous breakpoint regression model. The continuous breakpoint regression functions never performed much better than the closest discontinuous model as a predictor of centipede species richness. We suggest that the relatively low Z-values in our data partly reflect better dispersal abilities in centipedes than in other soil invertebrate taxa. Longer periods of isolation and more recent island formation may explain the somewhat lower constant c in the western Mediterranean islands compared to the Aegean islands. Higher breakpoint values in the western Mediterranean may also be a result of larger distance to the mainland and longer separation times. Despite the differences in the geological history and the idiosyncratic features of the main island groups considered, the overall results are quite similar and this could be assigned to the ability of centipedes to disperse across isolation barriers
Impacts of river water consumption on aquatic biodiversity in life cycle assessment-a proposed method, and a case study for europe
Contains fulltext :
128084.pdf (Publisher’s version ) (Closed access