Origin of life:
It was early considered as a mystery how a genetic apparatus, the basic machinery of life, could have originated.
In 1972 a sequence of hypthetical steps leading to such a genetic apparatus was invented *.
These steps are all logically consistent and chemical reasonable.
It was an argument against such a belief of a mystery on origin of life.
This approach was developed since then and it should stimulate future experimental work
to get to a deeper understanding of the origin of biological life as well as to reach artificial life.
Living entities are molecules or aggregates of distinctly interlocked molecules that can reproduce themselfes in a given environment and evolve, as a form, within appropriate achievable environments into forms of continuously increasing complexity and functional intricacy.
* H. Kuhn "Self-organization of molecular systems and evolution of the genetic apparatus"
Angew. Chem. Int. Ed. Engl. 11:798 - 820 (1972)