How do some fruits have self ripening ability?

Question

How do some fruits have self ripening ability?

Answer 1

No, all fruits require either the wind, bees, ants or hummingbirds to pollinate them, and the sun to help them ripen.

Answer 2

That happens because it's what they need to get their seeds out into the world. The seeds can be swallowed by animals and scattered in their droppings. The faster the fruits ripen the more offspring the species can have.

The mechanism is usually either a response to ethylene gas given off by other fruit that ripened earlier (bananas and apples) or to enzymes that cause the fruit to breakdown (overripe tomatoes).