The Morphogenesis of Multicellularity: 2 Signalling as Semiotic Alignment — Gradients, Feedbacks, and Positional Construal

Once cells begin to coexist within a shared field of potential, they must learn how to mean their place—how to construe and sustain their relation to others. This is the birth of signalling, the first grammar of multicellular life.

In a mechanistic story, signalling is treated as molecular cause and effect: a ligand binds to a receptor, a cascade follows, a gene is expressed. But in a relational ontology, signalling is semiotic alignment—each act of communication is an event of construal, in which a cell interprets and actualises its place within the collective topology.

Chemical gradients are not messages about position; they instantiate position. The morphogen field is the organism’s first language—a field of differential potentials through which cells construe “here” and “there,” “centre” and “periphery.” To exist in such a field is to participate in a shared semiotic structure: every gradient a clause, every response a reading of context.

Feedback loops then stabilise these construals. A cell that secretes a factor modifies the very field it interprets, tightening the reflexive loop. Over time, recursive feedback aligns local acts of construal into systemic coherence—a distributed understanding of organismal form. The field does not pre-exist the cells; it is their ongoing conversation, the organism’s discourse made matter.

This semiotic interpretation reveals why morphogenesis is so resilient: meaning precedes mechanism. If a cell is displaced or damaged, its neighbours re-construe the field, recalibrating gradients until coherence is restored. The pattern persists not through instruction, but through mutual interpretation.

We might say, then, that development is dialogue. The organism does not grow by executing a genetic script; it unfolds by negotiating alignment among its participants. DNA offers the vocabulary of potential, but the grammar—the construal of form—emerges in the relational field itself.

Multicellular life thus marks the moment when semiotic recursion becomes material. Every cell reads and writes the same living text, yet from its own position in the sentence. Morphogenesis is not information transfer but coherent interpretation: the field knowing itself through its own differentiation.