Why Biologists use Comparative Method?

Biologists are frequently interested in determining whether traits are functionally correlated. For example, do plants that are pollinated by birds tend to have red flowers much more often than those plants which are pollinated by other agents? Showing that a statistically major correlation between traits exists is sufficient to depict that the traits are usually related. A correlation among traits may have arisen not as they are functionally related but because they are historically (phylogenetically) related. Throughout the last two decades, comparative biologists have developed increasingly sophisticated methodologies termed collectively as the comparative method to take history into account. In a current survey, Freckleton et al. note that "Eighty-eight percent of data sets contained at least one character that displayed significant phylogenetic dependence and 60% of characters complete (pooled across studies) showed important proof of phylogenetic association". Phylogenetic history, and therefore, the comparative method, matters.