It seems as though we have jumped into a discussion and definition of the technical terms surrounding evolution without defining the central topic we are discussing, EVOLUTION.
Evolution is the biological change that organisms undergo over time. Scientists study evolution at two levels - microevolution and macroevolution.
Microevolution - genetic changes that occur over the course of a few generations. Falls into models of punctuated equilibrium and/or gradualism.
Macroevolution - patterns of change over many generations giving rise to new species. Guided by natural selection, mutation, gene flow and genetic drift.