It is the part of biodiversity which refers to the variation in genes that exists within a species. Genetic diversity serves as a path for specific populations to adapt itself according to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele. The population will continue for more generations because of the success of these individuals. Genetic diversity could sometimes relocate to post-genomic level by using polypeptide rearrangements. Analog to gene recombination, polypeptide rearrangement recombines partial gene products at post-translational level to produce new polypeptide sequences resulting indirectly in genetic diversity. The top open access journals are peer reviewed scholarly journals of hydrology. The top open access journals are freely available on the public internet domain, allowing any end users to read, download, copy, distribute, prink, search or link to the full texts of the articles. These provide high quality, meticulously reviewed and rapid publication, to cater the insistent need of scientific community.