And they shall turn away their ears from the truth, and shall be turned unto fables. Macro evolution refers to major evolutionary changes over time, the origin of new types of organisms from previously existing, but different, ancestral types. Examples of this would be fish descending from an invertebrate animal, or whales descending from a land mammal. The evolutionary concept demands these bizarre changes.
Micro evolution refers to varieties within a given type.
Change happens within a group, but the descendant is clearly of the same type as the ancestor. The small or micro evolutionary changes occur by recombining existing genetic material within the group. As Gregor Mendel observed with his breeding studies on peas in the mid 1800's, there are natural limits to genetic change. A population of organisms can vary only so much. No truly useful mutations have ever been observed.