Hydras can develop tumors if overfed, which can be passed to their clone offspring. A new study on this phenomenon enhances our understanding of transmissible cancers. While rare, such cancers exist in Tasmanian devils, dogs, and bivalves. Researchers, led by Sophie Tissot, used Hydra oligactis, which reproduces asexually and forms tumors under lab conditions, to study cancer evolution. They collected 50 hydras, overfed some to induce tumors, and observed tumor transmission to offspring, providing insights into the emergence and consequences of transmissible cancers.