From Molecules to Metabolism — VII. When Chemistry Began to Preserve Its Organisation

A chemical system can maintain itself.

Its reactions sustain one another.

Its boundary regulates exchange.

Its products feed back into its processes.

But there is another possibility.

Some organisations may persist more effectively than others.

A network that maintains the conditions for its own continuation can remain active.

One that cannot may dissipate.

This does not require reproduction yet.

It requires only a difference in persistence.

One arrangement continues because its organisation helps maintain the conditions of its continuation.

Another disappears because it does not.

Chemistry has therefore acquired something resembling a primitive selection among organisations.

Not selection by an external chooser.

Selection by differential persistence.

The important difference is between a chemical structure that happens to last and an organisation whose activity contributes to its own lasting.

A crystal can persist because its structure is stable.

A metabolic network persists because processes within it continually recreate the conditions that keep the network going.

The latter is historical in a new sense.

What happens within the system affects whether the system continues to exist.

We can now extend the sequence:

reaction → network → cycle → boundary → regulation → feedback → self-maintenance.

At each step, chemistry becomes more involved in producing the conditions of its own continuation.

And once some organisations persist while others disappear, the history of chemistry begins to matter.

A persistent organisation provides the starting conditions for what comes next.

Chemistry is no longer merely producing structures.

It is beginning to produce histories of persistence.

Perhaps the threshold toward life is not the appearance of a particular molecule.

Perhaps it is reached when an organisation becomes capable of making its own continuation a consequence of what it does.