Merging physics with biological evolution

One of the problems with physics is that it does not predict life or evolution. By rethinking of life and evolution as something arising from a series of events, a wad of boffins have come up with a way to explain life and evolution while staying within the confines of the laws of physics. A couple of examples helps clarify the unifying concept, called assembly theory (Nature paper, lay description).

Part a of the figure starts with little bits of stuff (atoms and small molecules) found naturally in the universe. Over time, the little bits bang into each other and form chemical bonds to make slightly larger molecules if the temperature, salinity, pH and other physical conditions for forming chemical bonds between the two interacting small things are right. Conditions like that have existed on Earth for about 3.7 billion years. Then, larger molecules collide and can form bigger molecules, e.g., diethyl phthalate at the end of the process shown at part a.

Part b shows how different amino acids, what proteins are made of, can form a linked sequence of 9 amino acids starting from four different amino acids. Part c shows how non-living assemblies can coalesce to form bigger structures such as crystals and aggregates. 

Selection or evolution fits in when some complex assemblies of molecules arise that have a trait of being able to enhance the rate of formation of new chemical bonds or breaking of existing bonds. This usually occurs either between two smaller chemical entities that are joined to form a bigger molecule or one entity breaking a bond in a bigger molecule to make two or more smaller molecules. In living things enzymes have this trait of being able to make or break chemical bonds to produce bigger or smaller products. In non-living systems such things are called catalysts. Enzymes are a subset of catalysts.

This theory does not conclusively prove that life arises only from self-assembly of increasingly complex structures. But at least this provides a plausible way to explain the origin of physical components that living creatures are made of without violating any laws of physics. As far as we know, when chemistry compatible with life exists, the possibility of life for physical entities exists. 

The still unanswered question is whether something else for life is needed, e.g., a soul, spirit or something else. 

By Germaine: Possibly an emerging critter