Food webs (i.e., networks of species and their feeding interactions) share multiple structural features across ecosystems. The factors explaining such similarities are still debated, and the role played by most organismal traits and their intraspecific variation is unknown. Here, we assess how variation in traits controlling predator-prey interactions (e.g., body size) affects food web structur...

Most of the isolates of Bordetella bronchiseptica obtained by this laboratory possessed a characteristic colonial morphology when grown on Bordet- Gengou agar (BGA) at 37 degrees C. The colonies appeared domed (Dom+) with a smooth colonial surface (Scs+) and a clear zone of hemolysis ( Hly +). From these Dom+ Scs+ Hly + BGA colony types arose flat (Dom-), smooth colonial surface (Scs+) and nonh...

The neo-Darwinian paradigm benefits from the assumption that phenotypic variation is gradual and that phenotype and genotype have a relatively simple relationship. These assumptions are historically inherited from the times of the neo-Darwinian synthesis and, consequently, do not include present understanding about development. In this study, understanding about the dynamics of pattern formatio...

Explaining the origin and maintenance of phenotypic variation remains a central challenge in evolutionary biology. Using the trematode parasite Maritrema novaezealandensis, we examined variability in several morphological, behavioural, and physiological phenotypic traits at the same time as controlling for genotype by using genetically identical parasite clonal lineages. We measured several mor...

BACKGROUND AND AIMS Among-population differentiation in phenotypic traits and allelic variation is expected as a consequence of isolation, drift, founder effects and local selection. Therefore, investigating molecular and quantitative genetic divergence is a pre-requisite for studies of local adaptation in response to selection under variable environmental conditions. METHODS Among- and withi...

BACKGROUND AND AIMS In species with specialized pollination, floral traits are expected to be relatively invariant and decoupled from the phenotypic variation affecting vegetative traits. However, inferring the degree of decoupling between morphological characters from patterns of phenotypic correlations is difficult because phenotypic correlations result from the superimposition of several sou...

The raw material for evolution is variation. Consequently, identifying the factors that generate, maintain, and erode phenotypic and genetic variation in ecologically important traits within and among populations is important. Although persistent directional or stabilizing selection can deplete variation, spatial variation in conflicting directional selection can enhance variation. Here, we pre...

This theory concerns the means by which animals generate phenotypic variation from genetic change. Most anatomical and physiological traits that have evolved since the Cambrian are, we propose, the result of regulatory changes in the usage of various members of a large set of conserved core components that function in development and physiology. Genetic change of the DNA sequences for regulator...

Phenotypes of individuals in a population of organisms are not fixed. Phenotypic fluctuations, which describe temporal variation of the phenotype of an individual or individual-to-individual variation across a population, are present in populations from microbes to higher animals. Phenotypic fluctuations can provide a basis for adaptation and be the target of selection. Here we present a theore...