Most biology texts villify Lamarck's concept of “inheritance of acquired characters” and leave the impression that all acquired characters are never transmitted to offspring. However, recent research indicates that this is not true! Some “acquired” traits are inherited. I profile some of these striking cases and their importance for evolution and for understanding a broader epigenetic context for heredity and ontogeny (the emerging field of “evo-devo”). Further, I discuss how such cases, even considered as exceptions, contribute to understanding the nature of science, both the role of general rules in biology and the occurrence of conceptual change, or paradigm shifts.