Many real-world problems can be formulated as global optimization problems. In recent years, evolutionary computation has been successfully applied in many such practical optimization problems which are hard to solve using traditional approaches due to their analytical intractability. However, practitioners are always in need of more effective and robust evolutionary algorithms as real-world problems become increasingly complex. In this paper, a niche evolution strategy (NES) motivated by S. Wright's (1931) shifting balance theory is therefore proposed. This NES employs several niches which evolve simultaneously and independently. During the evolutionary process, niche extinction and regeneration accompanied by gene flow occur at intervals of several generations. Two famous benchmark optimization problems are used to test the effectiveness of the proposed NES. The test results are compared with the corresponding results obtained from traditional single-population evolutionary computation and from distributed genetic algorithms (DGAs). It is shown that the NES is more effective than both of these approaches. It is also shown that the proposed NES can be readily applied in parallel computer architectures.

Current moIecuIar bioIogy techniques were deveIoped primarily for characterization of single genes, not entire genomes, and, as such, are not ideally suited to high resolution analysis of complex traits and the moiecular genetics of very large populations.Despite rapid progress in the human genome project effort, there is little doubt that radicaIIy new conceptual approaches are needed before routine whole genome-based analyses can be undertaken by both basic research and clinical laboratories.Physical mapping of genomes, using restriction endonucleases, has played a major role in the identification and characterizing various loci, for example, by aiding clone contig formation and by characterizing genetic lesions.Restriction maps provide precise genomic distances, unlike ordered sequencebased landmarks such as Sequence Tagged Sites (ST%), that are essential for optimizing the efficiency of sequencing efforts, and for determining the spatial relationships of specific loci.When compared to tedious hybridization-based fingerprinting approaches, ordered restriction maps offer relatively unambiguous clone characterization that is useful in contig formation, establishment of minimal tiling paths for sequencing, and preliminary characterization of sequence lesions.In addition, such maps provide a useful scaffold for sequence assembly, often critical in the final sequence finishing stage.Despite the broad applications of restriction maps, the associated techniques for their generation have changed little over the last ten years, primarily because they still utilize electrophoretic analysis.To help overcome these shortcomings, our laboratory developed the first practical non-electrophoretic genomic mapping approach, Optical Mapping, to meet this need.Optical Mapping is a single molecule methodology for the rapid production of ordered restriction