Macroevolution 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. Microevolution refers to varieties within a given type. Change happens within a group, but the descendant is clearly of the same type as the ancestor. This might better be called variation, or adaptation, but the changes are "horizontal" in effect, not "vertical." Such changes might be accomplished by "natural selection," in which a trait within the present variety is selected as the best for a given set of conditions, or accomplished by"artificial selection," such as when dog breeders produce a new breed of dog. Evolutionists assume that the small, horizontal microevolutionary changes (which are observed) lead to large, vertical macroevolutionary changes (which are never observed). This philosophical leap of faith lies at the eve of evolution thinking. Microevolution is used to refer to changes in the gene pool of a population over time which result in relatively small changes to the organisms in the population changes which would not result in the newer organisms being considered as different species. Examples of such microevolutionary changes would include a change in a species coloring or size. Macroevolution, in contrast, is used to refer to changes in organisms which are significant enough that, over time, the newer organisms would be considered an entirely new species. In other words, the new organisms would be unable to mate with their ancestors, assuming we were able to bring them together.
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