The origin of insect wings has long been debated. Central to this debate is whether wings are a novel structure on the body wall resulting from gene co-option, or evolved from an exite (outgrowth; for example, a gill) on the leg of an ancestral crustacean. Here, we report the phenotypes for the knockout of five leg patterning genes in the crustacean Parhyale hawaiensis and compare these with their previously published phenotypes in Drosophila and other insects. This leads to an alignment of insect and crustacean legs that suggests that two leg segments that were present in the common ancestor of insects and crustaceans were incorporated into the insect body wall, moving the proximal exite of the leg dorsally, up onto the back, to later form insect wings. Our results suggest that insect wings are not novel structures, but instead evolved from existing, ancestral structures.

昆虫翅膀的起源一直存在争议。这场争论的核心是翅膀是体壁上由基因共同选择产生的新结构，还是从祖先甲壳类动物腿上的出口（副产物；例如，鳃）进化而来。在这里，我们报告了甲壳类动物Parhyale hawaiensis中五个腿模式基因敲除的表型，并将这些与它们之前在果蝇中发表的表型进行了比较和其他昆虫。这导致昆虫和甲壳类动物的腿对齐，这表明存在于昆虫和甲壳类动物共同祖先中的两个腿段被并入昆虫体壁，将腿的近端出口向背侧移动，向上移动到背部，以后来形成昆虫的翅膀。我们的结果表明，昆虫的翅膀不是新结构，而是从现有的祖先结构进化而来的。