These anthropogenic toxicants, such as pollution, can cause severe perturbations of the genetic structure and affect genetic variation by four different ways: (i) increasing mutation rates, (ii) directional selection on tolerant genotypes, (iii) causing bottleneck events, and (iv) altering migration [1]. Several investigator have studied the effects of contaminant exposure on genetics of populations from terrestrial [e.g. 2–4] and aquatic [e.g. 5–9] ecosystems. Beside toxicants, genetic variability of natural populations may also be altered by natural events such as mutations, natural selection, stochastic processes and migrations. Gene flow is increased as a result of migration of individuals between populations as well as hybridization and nucleotide substitution [10]. The physiological or ecological significance of altered gene frequencies in populations from polluted and unpolluted sites may be detected by the observation of genotypic differences between populations of the same species
These anthropogenic toxicants, such as pollution, can cause severe perturbations of the genetic structure and affect genetic variation by four different ways: (i) increasing mutation rates, (ii) directional selection on tolerant genotypes, (iii) causing bottleneck events, and (iv) altering migration [1]. Several investigator have studied the effects of contaminant exposure on genetics of populations from terrestrial [e.g. 2–4] and aquatic [e.g. 5–9] ecosystems. Beside toxicants, genetic variability of natural populations may also be altered by natural events such as mutations, natural selection, stochastic processes and migrations. Gene flow is increased as a result of migration of individuals between populations as well as hybridization and nucleotide substitution [10]. The physiological or ecological significance of altered gene frequencies in populations from polluted and unpolluted sites may be detected by the observation of genotypic differences between populations of the same species