Trade-offs are thought to impose barriers to phenotypic diversification and may limit the evolutionary responses of organisms to environmental changes. In particular, locomotor trade-offs between endurance or maximal exertion capacity and burst performance capacity have been observed in some species and may constrain the ability of organisms to disperse. Here, we tested for the presence of loco...

A long-standing hypothesis asserts that plant-feeding insects specialize on particular host plants because of negative interactions (trade-offs) between adaptations to alternative hosts, yet empirical evidence for such trade-offs is scarce. Most studies have looked for microevolutionary performance trade-offs within insect species, but host use could also be constrained by macroevolutionary tra...

Recent empirical evidence suggest that tradeoff shapes can evolve, challenging the classica image of their high entrenchment. Here we model the evolution of the physiological mechanism that controls the allocation of resources to two traits, by mutating the expression and the conformation of its constitutive hormones and receptors. We show that trade-off shapes do indeed evolve in this model th...

In the gossiping problem, each node of a network starts with a unique piece of information and must acquire the information of all the other nodes. This is done using two-way communications between pairs of nodes. In this paper, we consider gossiping in n-node networks with n odd, where we use a linear cost model, in which the cost of communication is proportional to the amount of information t...

Biological robustness is a principle that may shed light on system-level characteristics of biological systems. One intriguing aspect of the concept of biological robustness is the possible existence of intrinsic trade-offs among robustness, fragility, performance, and so on. At the same time, whether such trade-offs hold regardless of the situation or hold only under specific conditions warran...

Phenotypic plasticity is nearly universal among organisms, and evidence indicates that plasticity can exhibit additive genetic variation and respond to selection. These findings have important implications for our understanding of how plasticity may be constrained and how its mechanistic structure may affect its evolution. Many life history trade-offs may be conceptualized as plastic traits, wi...

Natural ecosystems provide society with important goods and services. With rapidly increasing populations and excessive utilization of natural resources, humans have been enhancing the production of some services at the expense of others. Although the need for certain trade-offs between conservation and development is urgent, having only a small number of efficient methods to assess such trade-...

Trade-offs between immune function and reproduction are common to many organisms. Nevertheless, high energetic resources may eliminate the need for these trade-offs. In this study, we consider the effects of food availability on these trade-offs in a wild population of female sagebrush lizards (Sceloporus graciosus) during the breeding season. We manipulated food availability by supplementing s...

Title of Dissertation: TRADE-OFFS WITHIN AND BETWEEN SEXUAL TRAITS IN STALK-EYED FLIES (DIPTERA: DIOPSIDAE) Catherine L. Fry, Doctor of Philosophy, 2006 Directed By: Professor Gerald Wilkinson, Department of Biology The allocation of limited resources to competing body parts during development may affect both the absolute and relative sizes of physical traits, creating potentially dramatic cons...