Radiolaria

Radiolarians are microscopic single-celled organisms that build intricate mineral skeletons from silica. Haeckel studied them for decades, produced thousands of illustrations, and used them as the paradigmatic case of his ecological framework. The skeleton, taken alone and displayed in a museum case, is an exquisite object—a lattice of silica bars arranged in mathematically precise symmetries. But the skeleton alone is unintelligible. Its specific geometry is the fossilized record of an ecological dialogue: the silica concentrations in the water column, the temperatures and pressures and currents of the specific ocean layer the organism inhabited, the selective pressures that tested every variation of the geometry against the requirement of survival. Remove the ocean and the skeleton is beautiful but mute. The ecological framework is the only language in which the skeleton speaks.