Narrative Self Café v13A Interlude: Scaling PlacoSponges (How Tidal Shear Might Have Electrified Animals)

A TED-style lecture by D’Arcy Wentworth Thompson

Abstract

Animals are cellular configurations co-specializing caloric consumption — to collect and convert other life into energy.

Suppose an early, sponge-like sessile animal possessed placozoan-grade epithelial tissue: coherent, contractile, but chemically coordinated.

We hypothesize that as such a “placosponge” scaled in a hydraulically dangerous tidal region, growth pressure and shear stress favored a shift from diffusion-limited chemical coordination toward electrically excitable intercellular conduction.

Act I — The Geometry of a Growing Sponge

Ladies and gentlemen,

Biology is often told as a history of inventions — eyes invented, neurons invented, minds invented.

But life invents very little.

More often, it is geometry that compels.

Let us begin not with brains, nor with predation, nor with imagination — but with a placid shore, and a humble animal.