Student: Hey, can I copy your homework?
Friend: Sure, just change a few things so it doesn't look like you copied.
And that's how mockbusters are born. Mockbusters are movies that are obviously copied from popular movies, but altered enough to avoid a cease and desist. In the header image, I have included 4 examples. You can tell just from the titles that they're copied from popular movies.
A few similarities between movies isn't entirely unexpected. Harry Potter, for example, probably wasn't plagiarised from Lord of the Rings. But when enough story elements are shared, and especially when the title is practically identical, you get the idea that they share a common source.
But this common source isn't always a pre-existing version of the story. Sometimes, stories will share a number of common elements because they are based, at least to some degree, on the truth. As it happens, there are multiple such examples with regard to the Genesis flood.
All throughout the world, ancient cultures have preserved stories that seem to mirror the Genesis flood. In the header image, I have included a chart of a few of them. The stories are not all the same (not to mention several of these cultures were isolated by rather large bodies of water), ruling out plagiarism, yet they are all similar enough that they must have shared a common source. Either that or we have to accept that, statistically, it is entirely likely for two people to come up with the same ideas independently, and therefore all accused plagiarists should be given the benefit of the doubt, no matter how blatant the plagiarism (which would work out quite well for Darwin, as he was a known plagiarist).
The flood is forever cemented in human history just because Noah's descendants preserved the account. Though deteriorated through the natural limitations of oral transmission, the existence of flood legends that persist throughout the ages strongly supports the historicity of the Noahic flood. But the flood is not the main focus of the Bible. Rather, it is a warning.
The first global judgement was terrifying and devastating. The earth itself was forever changed. But it is a mere warning for the second. A day will come when God's patience with sin will wear thin, and He will enact His plan to end it once and for all. You may not even make it that long. Whether you survive until the end of days, or those days are postponed until long after your death, you will face God in judgement. It is therefore essential to get on the ark, so to speak. Christ alone has the power to save you from the wrath you deserve for your own rebellion against God. Therefore, repent, and place your faith in Christ, and Him crucified.