We have now seen two very different possibilities.
Organisms can interact while remaining distinct.
Or one organism can become integrated into another.
But there is another possibility:
many living processes can become coordinated without a single centre controlling them.
This is where slime moulds become particularly interesting.
One organism, many local processes
Physarum polycephalum is an acellular slime mould: essentially one enormous multinucleate cell rather than a collection of independent cells. It forms a branching network of tubes through which cytoplasm flows, and the network continually changes as the organism responds to its environment.
There is no brain.
No nervous system.
No central controller.
Yet the organism can explore its environment, locate nutrients and remodel its network in ways that support efficient transport.
The interesting question is not whether the slime mould is secretly thinking.
It is:
How can organised behaviour emerge without a central organiser?
Local responses can make a global pattern
A nutrient stimulus can alter signalling and cytoplasmic flow within the organism.
Those flows alter the network.
The altered network changes how resources are transported.
The new distribution of resources changes subsequent activity.
The organism therefore contains a recursive loop:
local condition → local response → changed network → changed conditions → further response
No part needs to possess a representation of the whole organism.
Yet the whole organism behaves as an integrated system.
This is a particularly clear example of collective organisation emerging from local interactions.
Where is the individual?
This makes slime moulds especially interesting for our question about individuation.
At one level, Physarum is one organism.
At another, its behaviour emerges from innumerable local processes coupled across a dynamically changing network.
The "individual" therefore does not sit at a single point.
Its organisation is distributed.
This complicates a simple picture in which value belongs to an organism and everything below that level is merely mechanical machinery.
The organism's value-sensitive activity is itself distributed across internal relations.
No centre does not mean no organisation
We should be careful with the word collective.
A decentralised system is not necessarily a collection of independent organisms.
Physarum is a single organism whose organisation is distributed.
That is different from a flock of birds or a bacterial population.
In the latter, distinct organisms coordinate.
Here, coordination occurs within one organism.
That distinction will matter later.
For now, the important point is that organisation need not have a central location.
From network to decision
The slime mould's behaviour can look surprisingly cognitive.
It can find routes through mazes, optimise transport networks and alter its behaviour in response to experience, although interpreting such behaviour as "learning" or "decision-making" remains a subject of active scientific discussion.
We do not need to settle the cognitive terminology.
The biological point is already remarkable.
A system without a nervous centre can integrate distributed processes into adaptive behaviour.
And then there are the social slime moulds
There is another slime mould lineage that complicates the picture further.
Dictyostelium spends part of its life as individual amoeboid cells. Under starvation, cells can aggregate and form a multicellular structure in which cells differentiate and cooperate. Collective behaviour is therefore built from organisms that were previously independent.
Now we have something much closer to the question that concerns us.
Individual value-organised cells become coordinated into a collective.
The cells have not simply been fused into one organism in the endosymbiotic sense.
They have joined together.
Two kinds of collective
We therefore have an illuminating contrast.
Physarum:
one organism → distributed organisation
Dictyostelium:
many organisms → collective organisation
Both can produce coordinated behaviour without a central brain.
But they do so through different organisational histories.
This is precisely the kind of distinction we need if we are to understand how mattering becomes relationally organised.
Collective coordination is not yet social mattering
In both cases, coordinated behaviour can emerge from local processes.
But we should still resist calling every such process social.
Our terminology gives us a useful progression:
biological value
↓
distributed organisation
↓
relational significance
↓
collective coordination
↓
social mattering
We should not assume that every arrow is inevitable.
The point is to discover what organisational change occurs at each transition.
The topology is already changing
There is nevertheless a striking connection with our earlier topology.
In Physarum, the network itself changes as the organism responds to conditions. Veins can be reinforced or reduced, altering the topology through which material flows.
The organism therefore does not simply move through a fixed network.
It constructs and reconstructs the network through which it acts.
This gives us a powerful biological precedent for our idea of a topology that evolves with the system.
What the slime mould teaches us
The lesson is not that slime moulds are little computers.
Nor that they possess human-like intelligence.
It is simpler and more interesting:
complex adaptive organisation can emerge from distributed, local processes without a central controller.
And that means that when we later encounter social organisation, we should not assume that a collective must first possess a central representation of itself.
The whole can emerge through the relations among its parts.
The next question
We have now encountered:
individual value;
organisms becoming significant to one another;
formerly independent organisms becoming integrated into new individuals;
distributed collective organisation.
But another transition remains.
What happens when living units become differentiated components of a larger body, while still retaining their own cellular organisation?
That takes us toward multicellularity — and to a particularly beautiful organism for thinking about the boundary between component and participant:
When Cells Become Participants
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