Fanciful evolutionary explanations that have little connection to facts are called "just-so" stories after the collection of stories by Rudyard Kipling. I just found a website with all of the the just so stories [Just So Stories]. It's worth reading a few to get some idea of what we're talking about when we say that the "explanations" of evolutionary psychology, for example, are no better than just-so stories.
The illustration is from The Elephant's Child, a story about how the elephant got its trunk.
'Come hither, Little One,' said the Crocodile, 'for I am the Crocodile,' and he wept crocodile-tears to show it was quite true.
Then the Elephant's Child grew all breathless, and panted, and kneeled down on the bank and said, 'You are the very person I have been looking for all these long days. Will you please tell me what you have for dinner?'
'Come hither, Little One,' said the Crocodile, 'and I'll whisper.'
Then the Elephant's Child put his head down close to the Crocodile's musky, tusky mouth, and the Crocodile caught him by his little nose, which up to that very week, day, hour, and minute, had been no bigger than a boot, though much more useful.
'I think,' said the Crocodile--and he said it between his teeth, like this--'I think to-day I will begin with Elephant's Child!'
At this, O Best Beloved, the Elephant's Child was much annoyed, and he said, speaking through his nose, like this, 'Led go! You are hurtig be!'