Definition: The nature of evolution is often misunderstood - quite frequently it is mangled terribly by creationists who are trying to argue against something they cannot define. Probably the simplest definition of evolution is this:
...evolution can be precisely defined as any change in the frequency of alleles within a gene pool from one generation to the next. (Helena Curtis and N. Sue Barnes, Biology 5th ed. 1989 Worth Publishers, p.974)
So what does that mean? First, an allele is just a variation of a gene. There is only one gene for eye color, but people with blue eyes have one allele of that gene and people with brown eyes have a different allele of that gene.
Evolution occurs in a gene pool over the course of generations. Thus, individual organisms do not evolve, in the sense of biological evolution. Evolutionary changes are those which affect distinct populations of organisms which constitue a gene pool. If these changes are heritable and passed along, it can be said that this population has evolved.
It should be noted that this has nothing whatsoever to do with the origins of life - evolution is about the changes that happen when life exists and makes no claims about where life may or my not have come from.
Also Known As: Darwinism
Alternate Spellings: none
Common Misspellings: none
Evolution & Creationism...
Is evolution a science? Is creationism a science? What is science? Is there evidence for either? Religious fundamentalists often attack evolution, but rarely from a positions of really understanding what evolution is and how it works. This FAQ will not only teach you more about the nature of evolution and evolutionary theory, but it will also explain some of the more common complaints and where they go wrong.