Models suggest that the mechanism of competition can influence the growth advantage associated with being large (in absolute body size or relative to other individuals in the population). Large size is advantageous under interference, but disadvantageous under exploitative competition. We addressed this prediction in a laboratory experiment on Rana temporaria tadpoles competing for limited food...

The relative importance of life-history variables to population growth rate (lambda) has substantial consequences for the study of life-history evolution and for the dynamics of biological populations. Using life-history data for 142 natural populations of mammals, we estimated the elasticity of lambda to changes in age at maturity (alpha), age at last reproduction (omega), juvenile survival (P...

BACKGROUND AND AIMS Nitrogen availability varies greatly over short time scales. This requires that a well-adapted plant modify its phenotype by an appropriate amount and at a certain speed in order to maximize growth and fitness. To determine how plastic ontogenetic changes in each trait interact and whether or not these changes are likely to maximize growth, ontogenetic changes in relative gr...

The ability of invasive plants to achieve higher relative growth rates (RGR) than their native counterparts has been widely documented. However, the mechanisms allowing invasives to achieve higher RGR are poorly understood. The objective of this study was to determine the basis for RGR differences between native and invasive forbs that have widely invaded nutrient-poor soils of the Intermountai...

This paper analyses relationships between relative growth rate (), seed mass, biomass allocation, photosynthetic rate and other plant traits as well as habitat factors (rainfall and altitude) in 20 wild species of Aegilops L. and one closely related species of Amblyopyrum (Jaub. & Spach) Eig., which differ in ploidy level (diploid, tetraploid and hexaploid). The plants were grown hydroponica...

OBJECTIVES This study investigated the relation between abdominal aortic aneurysm (AAA) wall stress, AAA growth rate and biomarker concentrations. With increasing wall stress, more damage may be caused to the AAA wall, possibly leading to progression of the aneurysm and reflection in up- or downregulation of specific circulating biomarkers. Levels of matrix metalloproteinase-9, tissue inhibitor...

—Phenotypic variation in a population is a key requirement for natural selection. Body size variation, in particular, can affect the dynamics, life history, and ecological relationships in a population. Past work suggests that variation in body size within a population reflects a competitive gradient in which larger individuals negatively affect smaller individuals because of the superior abili...

BACKGROUND AND AIMS Plant relative growth rate (RGR) depends on biomass allocation to leaves (leaf mass fraction, LMF), efficient construction of leaf surface area (specific leaf area, SLA) and biomass growth per unit leaf area (net assimilation rate, NAR). Functional groups of species may differ in any of these traits, potentially resulting in (1) differences in mean RGR of groups, and (2) dif...