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Energy availability can limit the ability of organisms to survive under stressful conditions. In Drosophila, laboratory experiments have revealed that energy storage patterns differ between populations selected for desiccation and starvation. This suggests that flies may use different sources of energy when exposed to these stresses, but the actual(More)
An increasingly popular experimental approach in comparative physiology is to study the evolution of physiological traits in the laboratory, using microbial, invertebrate and vertebrate models. Because selective conditions are well-defined, selected populations can be replicated and unselected control populations are available for direct comparison, strong(More)
We exposed adult male Drosophila melanogaster to cold, desiccation or starvation, and examined expression of several genes during exposure and recovery. Frost was expressed during recovery from cold, and was up-regulated during desiccation. Desiccation and starvation (but not cold) elicited increased expression of the senescence-related gene smp-30. Desat2(More)
1. We characterized year-round microclimate conditions (temperature and humidity) in and around necrotic cacti of the Sonoran Desert of southwestern North America. Necrotic cacti serve as host plants for four endemic species of Drosophila. 2. Flies in the field were exposed to high and variable temperatures, sometimes ranging between o5 C to >40 C in a(More)
Many adult and diapausing pupal insects exchange respiratory gases discontinuously in a three-phase discontinuous gas exchange cycle (DGC). We summarize the known biophysical characteristics of the DGC and describe current research on the role of convection and diffusion in the DGC, emphasizing control of respiratory water loss. We summarize the main(More)
We examined whether populations of Drosophila melanogaster could evolve a genetically based tolerance to high levels of toxic compounds (urea or ammonia) added to their larval food medium. We also examined whether tolerance to one compound may impart cross-tolerance to other compounds. Five populations selected for ammonia tolerance (AX), five populations(More)
Studies with the fruit fly, Drosophila melanogaster, have repeatedly shown that selection for postponed reproduction leads to increases in mean life span and increased stress resistance; including increased resistance to desiccation, starvation and ethanol vapors. We show that desiccation resistance declines with age in both short- and long-lived flies(More)
In the life history of holometabolous insects, distinct developmental stages are tightly linked to feeding and non-feeding periods. The larval stage is characterized by extensive feeding, which supports the rapid growth of the animal and allows accumulation of energy stores, primarily in the larval fat body. In Drosophila melanogaster access to these stores(More)
Understanding how climate change impacts natural systems requires investigations of the effects of environmental variation on vulnerable species and documentation of how populations respond to change. The willow beetle Chrysomela aeneicollis is ideal for such studies. It lives in California's Sierra Nevada on the southern edge of its worldwide range.(More)
We studied larval development and acquisition of metabolic resources in Drosophila melanogaster selected for adult desiccation resistance. Desiccation-selected (D) flies had longer developmental times in comparison with control populations, resulting in significantly higher body mass. No differences were found in larval growth rates, suggesting that(More)