As we go from species to kingdom in a taxonomic hierarchy, the...

Lower taxa share more common characteristics as compared to higher taxa. So, as we go from species to kingdom in a taxonomic hierarchy, the number of common characteristics decreases. as we go higher from species to kingdom, the number of common characteristics goes on decreasing. Lower the taxa, more are the characteristics that the members within the taxon share. Higher the category, greater is the difficulty of determining the relationship to other taxa at the same level. Hence, the problem of classification becomes more complex.