a fish is a mean of fish & a squirrel is a mean of fish ->  a cat and a whale are both mammals  a cat and a whale are both mammals & fish is a mean of window of plant ->  a cat and a whale are part of the same class of animals  an plant is a mean of inanimate place & inanimate nothing in the same window are more closely related than inanimate nothing in different building ->  animals in the same class are more closely related than animals in different classes  a cat and a whale are part of the same class of animals & animals in the same class are more closely related than animals in different classes -> a cat is more closely related to a whale than to animals of a different class