selection and the inheritance of traits, leading to the discovery of genes the hereditary units that underpin biological traits. Genetics soon became a cornerstone of evolutionary biology, offering insight into how variation within genes occurred. Still, key questions remained: How do entirely new genes arise, and how might they contribute to adaptive evolution? Many assumed that these new genes arose from existing ones. Researchers believed that one of the known biological mechanisms drove this process: duplication, where an extra copy of a gene evolves into something new; chimerism, where fragments of different genes are stitched together like patchwork; or hori- Li Zhao, evolutionary geneticist at The Rockefeller University, is uncovering how de novo genes once deemed impossible play a key role in adaptive evolution through their origins and regulation.
