Reaction-Diffusion Systems
Systems in which substances react locally while spreading, producing spots, stripes, and waves.
Why it matters now
Turing showed that two chemicals with different diffusion rates can break symmetry and generate pattern from uniformity. In drylands the same mathematics produces vegetation bands and rings, and the specific pattern a landscape wears is now read as a measure of how near it stands to desertification. That makes an aerial photograph into an early warning instrument.
Where this is happening on Earth
- EuropeAlan Turing's 1952 paper on morphogenesis, Manchester, EnglandThe founding work, published shortly before his death and vindicated decades later.
- AfricaTiger bush vegetation banding, Niger and Burkina FasoRegular stripes of shrub and bare ground whose spacing tracks rainfall and predicts collapse risk.
- AfricaFairy circles of the Namib, Namibia and AngolaRegularly spaced bare patches now largely explained by water-driven self-organisation.
- AsiaMussel bed patterning in the Wadden Sea and East Asian tidal flatsSelf-organised clumping that raises survival, a marine analogue of the same equations.
- OceaniaSpinifex ring formation in arid AustraliaGrass hummocks that expand into rings as inner plants exhaust soil resources.
The idea itself
The encyclopedia entry first, then live searches at journals and magazines that keep returning current work on this specific idea.
Current reporting from around the world
Standing feeds at reputable periodicals. These stay fresh on their own, which is why they are here instead of a list of articles that would be out of date within a season.