Present day biodiversity need to be explored though the clues of evolution and migration for understanding the ancient relationship/origins. Traditionally zoogeographical distribution was a handy tool for deriving evolutionary relationships. Presently molecular comparison among species by constructing phylogenetic tree using nucleic acid and protein sequences is widely used in exploring the same. Secondary structure of RNA (which accounts for negative free energy of molecule) has also been employed in relating two or more than two species in some studies. Construction of secondary structure from 28S rRNA data of few species of Gyrodactylus is employed in molecular comparison; evolution pattern and level of complexity developed by organisms itself. The analysis performed in this work reflect that a range of patterns of evolution in the secondary structure of rRNA (number and types of loops) can be set by exploiting one species of a cluster as common/representative species. Geo-mapping of the different species when compared with phylogenetic tree bring better understanding in probable evolution/migration patterns in their hosts.