»Creationism vs Evolution«

Over thirty parameters of the universe have been identified that must be carefully fixed in value for any kind of conceivable life (not just life as we know it) to exist at any time in the history of the universe. Some examples of these are given in Table 1.

oxygen quantity in atmosphere
if greater: plants and hydrocarbons would burn up too easily.
if less: advanced animals would have too little to breathe.

abiogenesis: The supposed development of living organisms from nonliving matter.

evolution: Change in the genetic composition of a population during successive generations, as a result of natural selection acting on the genetic variation among individuals, and resulting in the development of new species.

microevolution: Evolution resulting from a succession of relatively small genetic variations that often cause the formation of new subspecies.

macroevolution: Large-scale evolution occurring over geologic time that results in the formation of new taxonomic groups.

Typically, observable instances of evolution are examples of microevolution, for example, bacterial strains that have become resistant to antibiotics. Because microevolution can be observed directly, both pro-evolution and some anti-evolution groups agree that it is a fact of life.

Some critics, mostly creationists, accept that microevolution occurs in the short term, whereas macroevolution, specifically leading to speciation, is expressly rejected. They claim that known sources of variation can only account for variation within species, and can not account for the variation between larger taxonomic groups, thus making macroevolution impossible.

In the creationist hypothesis of intelligent design this distinction is absolute and central. Intelligent design advocates argue that microevolution may be explained by constant, observable, natural forces, but that macroevolution must be explained by other forces.