How does evolution explain mammals like whale?

A cow cannot give birth to a whale. But give the cow a few million years, and maybe something like a whale may evolve. Anmd don't you know better than to quote the Bible to people who know it is not 'inspired by god', and think it is just a book? A terrific book, yes, but just a book, written by men. Remember, when arguing with atheists, you will be wasting you time wuoting from the Bible. Argue from your OWN mind, don't quote someone else!