Why are French and Italian so strikingly similar? Common sense dictates that they are descended from an earlier language: Latin, as it happens. The massive similarities alone are enough to demonstrate common descent, although we also happen to have “fossil” evidence in the form of writing. Just as linguists have constructed vast family trees of related languages on the basis of similar words, biologists have done the same on the basis of similar genetic codes. Young earth creationists’ denial of common descent forces them to deny common sense, motivated only by a dogmatic adherence to a literal interpretation of Genesis.