The role of DNA segment that do not code for proteins

The non-coding regions of DNA are called introns. They are significant in evolution since they offer a great 'recipe' for recombination with genes/exons. Therefore, this offers variations among individuals on which natural selection could act upon to help a population adapt to changes in the environment. Introns also offer an additional step in gene regulation through the splicing of introns in making of mRNA.

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.