Chinese Scientists Resolve Insect Wing Evolution Puzzle

An international research team, spearheaded by scientists from the Chinese Academy of Sciences Nanjing Institute of Geology and Palaeontology, has successfully deciphered the evolutionary relationships of ancient winged insects using phylogenomic methods. The findings, published in the journal PNAS, resolve a puzzle that has perplexed entomologists for over 100 years.

The study confirms that mayflies and dragonflies are sister groups, forming the "ancient wings" (Palaeoptera). This group, in turn, is identified as the sister lineage to the "neopterans" (Neoptera), insects capable of folding their wings. This relationship had been a subject of debate due to the difficulty in resolving it with previous analytical approaches.

The research team utilized China's abundant mayfly diversity, newly sequencing the genomes of 16 native species. By integrating this data with genomic and transcriptomic information from over a hundred other insect species, they addressed limitations in previous studies, particularly concerning the sampling of key lineages.

The findings indicate that the two lineages independently evolved distinct wing structures. Palaeopterans developed rigid wing bases for gliding or fast flight, while neopterans evolved a foldable wing-root joint for navigating confined spaces. The study also updates the estimated origin of winged insects to the Early Devonian period, approximately 419 to 393 million years ago.

These conclusions revise previous hypotheses based on morphological characteristics. The research underscores the significance of insect flight as a major evolutionary innovation. The parallel development of these two lineages has contributed to the diverse flight mechanisms and species richness observed in insects today.