These stories often assume that Lamarck Was Right, proposing that some modern person, animal, or plant inherited an acquired, non-genetic characteristic from a particular ancestor. See the sister trope, Painting the Frost on Windows.

Named for a collection of children's stories by Rudyard Kipling, Just So Stories, which included tales like 'How the Whale Got Its Throat' and 'How the Camel Got Its Hump' (Kipling had written a kind of tryout called 'How Fear Came', explaining how tigers got their stripes and why they aren't herbivores, in The Jungle Book). This can backfire if the kid gets into trouble by naively believing what you told them. Also, Lies to Children is the easy way out whenever a small child asks you about something you don't know how to explain: the real explanation is often too complicated for them to understand, and you might not even know the answer yourself, so you can use the 'Just So' Story to satisfy the kid's curiosity and get them out of your hair. Still, even modern people are entertained by these stories despite knowing better than to believe them literally. Some of these stories are weird enough that relating these to modern ears may elicit cries of Values Dissonance. Typically, inanimate forces of nature are personified as gods or spirits, complicated variables are simplified in order to identify one clear-cut cause, and explanations of natural phenomeona that contradict modern scientific knowledge are accepted in a culture which lacks modern scientific methods, instruments, and theories. The 'Just So' Story (also known as a 'pourquoi note French for 'why?' story,' 'origin story,' or 'aetiological tale' note from the Ancient Greek αἴτιον, 'cause') is a myth or folktale which, to quote Wikipedia, 'purports to describe the origin of some feature of the natural or social world.' The question, often posed to an adult by a child, could be 'why do the seasons change?', or 'why do zebras have stripes?', or 'why do people speak different languages?' The answer given is usually that some god(dess), hero(ine), or mythical ancestor did something a long time ago that caused that thing to become that way: ' Because Hades abducted Persephone and took her to the underworld', or ' Because the zebra's son burned himself in the baboon's campfire ', or ' Because God punished humanity for trying to build a tower to heaven.'

The just so stories