In the evolutionary or ecological studies, it is very important to consider both homologous and analogous feature. But it is always good to find interrelation by finding homologous relationship among two species. When all the similarities are completely studies then we search for analogous features between two species. The best is to say that generic level is studied with respect to homologous features. But specie and sub-specie level is highly modified and studied under analogous features and interrelation between two species.
