The origins of novelty

摘要

Understanding the origin of complex traits is among the most enduring puzzles in evolutionary biology. On the one hand, evolution operates within a framework of descent with modification -everything new must come from something old. On the other hand, structures such as the eye, the wing and the turtle's shell stand out because they lack obvious correspondence to the old. On page 83 of this issue, Prud'homme et al.address this puzzle by connecting a complex and highly diverse trait - the helmet of membracid treehoppers - to its origins in both development and evolution.