From 2speccers2tools wiki

Some young Leafed Radiomolds got carried by the wind and landed beyond the cliffs and ended up within the Horrible Rectangle Island Tundra. Those that landed there would eventually come to thrive and became a new species known as the Radiobush. Their leaf-like lobes help gather sunlight and take in ambient levels of spite from the air around them while the Radiobush also gets energy from radiation. The cell wall-like structures around their cells came in real handy, since it allows them to retain water during the cold and dry months within the tundra. While the Radiobush still has their cells producing adhesive secretions that stick to solid surfaces, they have also developed small root-like structures to anchor themselves and thus aid the sticky secretions with staying in place. Just like their ancestors, the nucleus membrane of a Radiobush cell incorporates lead into it so as to provide shielding so it doesn't irradiate itself to death. Much like their ancestors, the Radiobush produces small versions of themselves with large leaves so they can be carried by the wind a certain distance before landing and becoming a new Radiobush. Since the species leaves the immediate area around them with a slightly higher than normal amount of background radiation and the Horrible Rectangle Island Tundra has almost no competition aside from young Pissing Sky bushes, the Radiobush quickly exploded in numbers and left the landmass with moderate amounts of background radiation. This proved to be disastrous for the other species present, with the Pissing Sky Bush, baloon animal, Yesdent., and other species that spend part of their time in the sky becoming rare, while the local populations of big m'unguses, Nostalgias, Chi’mpuses, and even spheres of death dying out. The Snufflers lost the majority of their diversity on the landmass, with only species that rapidly adapted to resist some amount of radiation surviving. Microbes such as the Dire tom and Yes-Sapien were able to make a living due to breeding faster than they could succumb to radiation poisoning while the nuclear sunscreen poopycell positively thrived due to the exploding numbers of Radiobuses since they could use the ambient amounts of radiation for their own use.