Scientists explored the evolutionary success of leaf beetles, the most diverse herbivores on Earth. They showed that symbioses with bacteria have evolved repeatedly and independently in different beetle lineages, and contribute significantly to the efficient digestion of plant food. These symbiotic relationships provide clues as to how genetic material was exchanged between bacteria and beetles. Key findings highlight the role of horizontal gene transfer, the incorporation of foreign bacterial genetic material into the beetle genome, which is thought to be the result of earlier symbioses. Overall, the study emphasizes the importance of microbial partnerships and genetic exchange in shaping the dietary adaptations of leaf beetles, which facilitated the evolutionary success of leaf beetles.
