In the Beginning: A Lively Debate
The theory, also known as "descent with modification,'' posits that new species have evolved following many minor changes from parents to offspring over billions of years. Cumulatively, the changes give some species an advantage over others in the struggle to survive. The theory, which has been modified over time, is based on evidence from the fossil record, biochemistry, and genetics. It does not seek to determine an underlying reason for the process.
Creationists assume a divine origin of life. Some believe in the "micro-evolution'' of nonhuman species while others accept evolution as part of a divine order.
"Scientific creationism'' sets out to reconcile biblical accounts with physical evidence from geology and other fields.
Adherents to scientific creationism believe that life began exactly as described in the Book of Genesis and has existed, at most, for 10,000 years.
'Intelligent Design' Theory
The theory assumes that there is an overall design to the development of life. Supporters of evolution say counter-examples in nature disprove the concept, adding that the theory implies a supernatural architect whose existence cannot be proved scientifically.
As espoused by creationists, "abrupt-appearance theory'' argues that all life appeared suddenly, without intermediate, ancestral forms.
Some creationists have begun to falsely argue that this belief is supported by the scientifically derived concept of "punctuated equilibrium.''
This controversial development in evolutionary theory draws on evidence from the fossil record to argue that new species tend to develop in short spaces of geological time from ancestral forms, rather than at a gradual, uniform rate.