Academic dissertation To be presented for public criticism, with permission of the Faculty of Biosciences,

Hotter is better is a hypothesis of thermal adaptation that posits that the rate-depressing effects of low temperature on biochemical reactions cannot be overcome by physiological plasticity or genetic adaptation. If so, then genotypes or populations adapted to warmer temperatures will have higher maximum growth rates than those adapted to low temperatures. Here we test hotter is better by meas...

Cold-loving or psychrophilic organisms are widely distributed in nature as a large part of the earth's surface is at temperatures around 0 degrees C. To maintain metabolic rates and to prosper in cold environments, these extremophilic organisms have developed a vast array of adaptations. One main adaptive strategy developed in order to cope with the reduction of chemical reaction rates induced ...

Cold-adapted, or psychrophilic, organisms are able to thrive at low temperatures in permanently cold environments, which in fact characterize the greatest proportion of our planet. Psychrophiles include both prokaryotic and eukaryotic organisms and thus represent a significant proportion of the living world. These organisms produce cold-evolved enzymes that are partially able to cope with the r...

Hatchlings of the North American painted turtle (Chrysemys picta) typically spend their first winter of life inside the shallow, subterranean nest where they completed incubation the preceding summer. This facet of their natural history commonly causes neonates in northerly populations to be exposed in mid-winter to ice and cold, which many animals survive by remaining unfrozen and supercooled....

We explored the extent to which a phenotypic trait (walking speed) of Drosophila melanogaster is influenced by population, developmental temperature, adult temperature, and age. Our goals were to estimate the importance of these factors and to test the beneficial acclimation hypothesis. We measured speed of flies from two populations (the Congo and France) that developed at different temperatur...

Understanding how populations adapt to changing environmental conditions is a long-standing theme in evolutionary biology. Gene expression changes have been recognized as an important driver of local adaptation, but relatively little is known regarding the direction of change and in particular, about the interplay between plastic and evolutionary gene expression. We have previously shown that t...

Recent work on the effect of changes in the environmental temperature on the local and general response to injury is discussed. Both the acute and delayed responses to injury are affected by changes in environmental temperature. Thermoregulation in the rat is impaired by an injury and there is an optimum temperature for survival after the injury. The acute response to injury in the rat is also ...

Reproductive timing in corals is associated with environmental variables including temperature, lunar periodicity, and seasonality. Although it is clear that these variables are interrelated, it remains unknown if one variable in particular acts as the proximate signaler for gamete and or larval release. Furthermore, in an era of global warming, the degree to which increases in ocean temperatur...

Lysobacter sp. strain A03 is a protease-producing bacterium isolated from decomposing-penguin feathers collected in the Antarctic environment. This strain has the ability to degrade keratin at low temperatures. The A03 genome sequence provides the possibility of finding new genes with biotechnological potential to better understand its cold-adaptation mechanism and survival in cold environments.