Environmental niches

The processes of evolution have been remarkably successful in creating animals that are well adapted to their environment. By continually adjusting the population through genetic mutation, evolutionary change works toward the perfect individual to fill a particular environmental niche. Not every new individual is well suited to its environment, of course, and the fitness of new individuals is repeatedly tested as the animals try to survive, prosper, and reproduce. 

Municipal waste water treatment plants receive daily considerable amounts of non-metabolized antibiotics and metabolites thereof, as well as other environmental pollutants. Moreover, domestic waste water is a complex mixture of human commensal and environmental bacteria, which get in contact with considerable amounts of antimicrobial agents and other substances with unknown effects on bacterial metabolism and microbial communities [38,54-57]. The free movement of bacteria between different environmental niches and the easiness with which bacteria become adapted to new conditions contribute to a rapid dissemination of antibiotic... 

Three generic approaches for all aflatoxin-susceptible crops could be used to exclude toxigenic fimgi from their environmental niches and to regulate aflatoxin biosynthesis ... 

The present review instead will discuss how the structure and properties of endotoxin from a chronically infecting bacterium, in contrast to one that causes acute infection, are adapted to fit the environmental niche of the respective microbes using H. pylori and C. jejuni as model organisms. Furthermore, the pathogenic consequences of these endotoxin structures will be discussed. Although the core OS... 

Fig. 7. Stylized temperature dependent growth model for hypothetical warm water and cold water species (Schmidt et al. 2006) based on Bradshaw (1961). The environmental niche is dived into optimum growth, a reproductive range, the minimum temperature for growth and the physiological limit leading to lethal conditions.

Competitiveness. Unlike chemical pesticides, microbial pesticides are living entitles which may survive, replicate and compete with other species for space and food sources. These factors, alaie, do not constitute a hazard, but do require an evaluation for which there is no coutiterpart for chemical pesticides. Such an analysis must consider whether characteristics have been engineered into a microorganism v ich may permit it to establish itself in new environmental niches. If so, then its potential to exert adverse effects ai nontarget species must be considered. 

The processes of optimum-seeking have been remarkably successful in lots of real-world phenomena, such as human evolution, food-seeking of ant colonies, and improvisation of musicians. By using stochastic heuristic individual searches and generation processes, these phenomena work toward a perfect individual to fill a particular environmental niche. It is naturally expected that evolutionary optimization processes can be created by modeling the behaviors of these phenomena. The evolutionary optimization techniques were thus developed to perform this function, which mimics the optimum-seeking processes of these phenomena in a computer program. 

Biodegradation of a polymer is not a uniform process. Instead, both the rate and the maximum level of biodegradation of a specific material are very much determined by the environmental niche. These environmental niches can differ with regard to ... 

An overview of the different environmental niches in which a material can end up is given in Figure 5.3. Because of the differences in rate and level of biodegradation related to the environmental niche, it was necessary to develop different norms for each niche individually. 

Figure 5.3 Overview of the different environmental niches for end-of-life...

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