I agree that Harry Potter is fictional and that some of the Bible relates to historical figures. But any narrative is embellished and changed over time. The four accounts of Jesus' life in the New Testament don't agree on events. Archaeological finds don't vindicate things in the Bible, it's too easy to find an old artefact and conveniently match it to something written thousands of years ago. And thanks, I have an education, in physics, which is why I can point to lots of scientific findings.
There are over 8 million species of animal on Earth. If there weren't that many at the time of the supposed flood, then there's only two explanations. The flood was not a global catastrophe (just a localised one) or new species have evolved since the time of the supposed flood. But I guess the Young Earth believers and creationists don't want to consider the evolution option.