The individuals having characters best adapted to the surroundings are able to survive. Their characters, that is, the genes present in them, pass on to the further generations. Biological evolution is basically, change in living organisms over a long period of time. Evolutionary theory states that different types of living organisms originate from common ancestor due to modifications in successive generations.All living organisms show variation in characters. Biological classification is arrangement of living organisms into groups based on similarities and differences observed among them. The smallest group or taxon is species which consists of individuals which can successfully reproduce with each other. It is observed that, generally, the organisms having close evolutionary relationship are placed together in a smaller taxon. As we go to higher taxon, the relatedness decreases. This is consistent with the evolutionary theory. Therefore classification helps to establish evolutionary relationship.
How does our modern classification system show the evolutionary relationship among organisms?