"De novo" genes evolve from previously non-genic DNA. This strikes many of us as remarkable, because it seems extraordinarily unlikely that random sequence would produce a functional gene. How is this possible? In this two-part review, I first summarize what is known about the origins and molecular functions of the small number of de novo genes for which such information is available. I then speculate on what these examples may tell us about how de novo genes manage to emerge despite what seem like enormous opposing odds.
Keywords: De novo genes; Evolutionary novelty; Gene birth; Genetic novelty; Lineage-specific genes; Taxonomically-restricted genes.
© 2022. The Author(s).