The theory of emergence offered the solution.
In terms of the concept, Ernst Mayr writes:
Systems almost always have the peculiarity that properties of the whole cannot be derived (not even in theory) from even the most complete knowledge of the components, regardless of whether they are considered individually or in other partial combinations.
This emergence of new qualities in an entity is called emergence and is often used in an attempt to explain such difficult phenomena as life, mind and consciousness. In fact, emergence is no less typical of inorganic systems.
(Mayr 2002, p. 52)
Biological organisms are complex systems with new properties that require a new set of rules, namely an independent biological theory. Achim Stephan mentions four distinguishing features of emergent theories in his book on emergence (German: Emergenz, Paderborn, 3rd ed. 2007, pp. 14 – 25):
1. Naturalism: only natural factors play a role in evolution
2. Innovation: something genuinely new is created
3. Systemic properties
4. Hierarchy of the levels of existence: especially the areas of the material, the biological, and the spiritual.