By looking at how the birds interact with fruits in different environment, you can determine where birds are from, what beaks specialize in eating what kind of food, and how those traits came to be (Darwinism)
Many disorders can be heritable through the generation. Knowing the patterns of disorder heredity, either it is dominant or recessive, autosomal or sex-linked is a great advantage in making a diagnose. It should be taken into consideration that some diseases can be influenced by environmental factors. For example, a person knows its parents had high blood pressure. That person has a predisposition for high blood pressure too. But, since heredity and family medical history is known, that person can prevent the appearance of the disease by taking care of its condition, performing physical activities, avoiding smoking, fat diet, etc.
