Nature's Tile Shop

Life keeps evolving these geometric patterns

- Anirban Mukhopadhyay

The same tile structures with soft joints between are found across the tree of life, including on mirror spiders' abdomens (1), chitons' shell plates and girdles (2), salak fruit's outer covering (3, 4), butterfly wing scales (5) and armadillo lizards' bony plates (6, 7).

THE MIRROR SPIDER can rapidly shift a patchwork of minuscule reflective plates underneath its abdomen's outer surface, altering the pattern of mirror-like flashes. This uncommon display comes from common building blocks: Similar tilelike arrangements of plates and soft joints appear throughout the tree of life, from turtle shells to tropical fruit peels. Researchers have now compiled 100 examples of this pattern across animals, plants, microbes and viruses, which they describe in PNAS Nexus.

Study coauthor Mason Dean, a biologist at City University of Hong Kong, first noted a regular tiled pattern in micro computed tomography scans of a ray skeleton.