In the late twentieth century, scientists discovered a new form of life on Earth, which they called Archaeans. At the time it was discovered, this life form did not fit into scientists’ current classification scheme for biological life. It was generally believed that the vital cellular components of any living organism essentially break down at temperatures above 60° Centigrade. This thermal limit of cellular life, scientists thought, was fixed across all biological organisms. But in recent decades, Archaeans have repeatedly demonstrated that what had been thought to be the limit was too low. In fact, so-called “extremophilic” Archaeans have been discovered to thrive in temperatures as high as 160° Centigrade.
What conclusion does the discovery of Archaeans support?