15.7.05

Why Are Scientists Confident that Complex Biological Systems Evolved Gradually?

By Jason Rosenhouse
Recall that natural selection operates by preserving small, favorable variations that occur naturally in any population of organisms. Over time these variations accumulate to the point that large-scale change is the result. This implies that natural selection works by modifying structures already present in the organism. It does not craft new, complex systems from scratch.
http://www.csicop.org/creationwatch/actualism.html