Researchers have discovered that aggressive green wall lizards, dubbed 'Hulk' lizards, are rapidly outcompeting and eliminating yellow and orange color morphs that coexisted for millions of years. The common wall lizard, Podarcis muralis, across the Mediterranean now shows only white-throated individuals in many populations. A study analyzing over 10,000 lizards revealed this shift in evolutionary dynamics.
For millions of years, populations of the common wall lizard (Podarcis muralis) maintained a balance of three throat color morphs: white, yellow, and orange. Each morph represented distinct survival strategies, such as territorial competition and mate attraction, fostering coexistence across the Mediterranean region. Tobias Uller, professor of evolutionary biology at Lund University, noted, 'We are seeing how the coexistence of several different color morphs, something that has been stable for millions of years, is being lost over a very short evolutionary time scale.'