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.
Two types of macroevolution are divergent evolution and convergent evolution. Divergent evolution occurs when two separate species evolve differently from a common ancestor. Speciation is a result of divergent evolution, and occurs when one species diverges into multiple descendant species. Darwin's finches are an example of this. Convergent evolution occurs when species have different ancestral origins, but have developed similar features.