In the back pages of New Scientist magazine, in a section called Almost the Last Word, readers pose questions that are then answered, usually by well-informed other readers. In the July 13, 2024 edition, someone asked, “Once life is established, is the evolution of intelligence inevitable?”

Garry Trethewey of South Australia attempted the first answer. “Probably not. Wings have evolved four times—in birds, bats, pterosaurs and insects. Legs and eyes have evolved multiple times. Swimming ability has also evolved many times. But intelligence has only evolved once, very recently. Is it useful? Is it a survival trait? Is it somehow better than not-intelligence? Given the 8 billion of us versus the vastly greater numbers of microbes and how long they have been around, I would put my money on the microbes.”