An intervening variable facilitates a better understanding of the relationship between the independent and dependent variables when the variables appear to not have a definite connection. They are studied by means of operational definitions and have no existence apart.
Difference between Microevolution and Macroevolution. â¢ Micro evolution refers to visible changes in a population of the same species over a period of time. â¢ Macroevolution is what evolution is as described by the theory of evolution by Darwin.
But in any case, equating kind with family is a red herring in asking for examples of macroevolution. The definition of macroevolution as accepted by all biologists is evolution at or above the level of species. In other words, speciation itself (the birth of a new species) is an example of macroevolution.