Sökning: "evolutionary changes"
Visar resultat 26 - 30 av 239 avhandlingar innehållade orden evolutionary changes.
26. A Unified Multitude : Experimental Studies of Bacterial Chromosome Organization
Sammanfattning : Bacteria are many, old and varied; different bacterial species have been evolving for millions of years and show many disparate life-styles and types of metabolism. Nevertheless, some of the characteristics regarding how bacteria organize their chromosomes are relatively conserved, suggesting that they might be both ancient and important, and that selective pressures inhibit their modification. LÄS MER
27. Genetic response to pollution in sticklebacks; natural selection in the wild
Sammanfattning : The last century, humans have been altering almost all natural environments at an accelerating rate, including the Baltic Sea that has highly eutrophicated areas and many coastal industries such as Pulp-mills. For animals living in a habitat that changes there are basically two alternatives, either to cope with the change or become locally extinct. LÄS MER
28. Thriving in extremes : Local adaptation of grasses (Poaceae) to geothermally heated soils on a subarctic island
Sammanfattning : Temperature is one of the most decisive parameters when it comes to determining characteristics and distributions of life worldwide. For plants, as sessile organisms, it is particularly important to be able to deal with the temperatures they are exposed to at a given location. LÄS MER
29. Life history evolution during a climate-driven butterfly range expansion
Sammanfattning : Climate change pushes species polewards and upwards – as temperatures rise, species move to areas that were previously too cold for them. During range expansions, species encounter unfamiliar environmental conditions, which may require evolutionary adaptation, but expanding populations may often be hampered by their genetic and demographic properties. LÄS MER
30. Haploid selection in animals : Exploring the fitness consequences and underlying mechanisms
Sammanfattning : A consequence of sexual reproduction in eukaryotes is the evolution of a biphasic life cycle with alternating diploid and haploid gametic phases. While our focus in evolutionary biology is on selection during the diploid phase, we know relatively little about selection occurring during the haploid gametic stage. LÄS MER