Wildlife of Britain

The Weird Genetics of British Whitebeams (Sorbus) Britain’s whitebeams are one of the strangest evolutionary stories in European botany.  On the surface, they look like modest trees clinging to cliffs, limestone gorges, and coastal slopes. But genetically, they represent something far more unusual: a rapid burst of speciation driven not by slow evolutionary divergence, but by hybridisation followed by cloning—often producing species that exist nowhere else on Earth. To understand why Britain is globally important for the genus Sorbus, you have to begin with how most trees normally evolve.  In most genera, new species arise gradually. Populations become separated, mutations accumulate, and eventually reproductive barriers form. Over thousands to millions of years, a lineage splits into distinct branches of the tree of life. Sorbus in Britain breaks this rule almost entirely. Hybridisation: the starting point of chaos The foundation of British whitebeam diversity lies in two rel...