The origin of insect wings remains an enigma in the realm of evolutionary biology, posing a puzzling question about their development and initial purpose before achieving efficient active flight. Researchers at the Biology Centre of the Czech Academy of Sciences have delved into this mystery by exploring prehistoric fossils belonging to an ancient insect group.
While various hypotheses exist regarding the origin of insect wings, the debate revolves around whether the common ancestor of winged insects lived in an aquatic or terrestrial environment. Recent findings from an international team, including scientists from the Biology Centre, shed light on this puzzle. The study, published in Communications Biology, unveils new Paleozoic fossils from the Carboniferous period, representing larvae of an ancient insect group called Palaeodictyoptera.
These larvae, discovered in a Lower Saxony quarry, exhibit body structures resembling a hypothetical winged insect ancestor. Notably, the fossils provide evidence of adaptations for aquatic life, including flattened projections on the abdomen sides functioning as gills. The larvae also reveal three pairs of future wings on the thorax, structurally similar to the gill plates on the abdomen, hinting at a dual role in oxygen intake from the aquatic environment.
Pavel Sroka from the Institute of Entomology at the Biology Centre emphasizes the significance of these findings, noting that while the fossils may not represent the direct ancestor of winged insects, they belong to a relatively ancient insect group. The aquatic environment’s potential influence on the early stages of winged insect evolution gains support from the observation that larvae in other ancient insect taxa, like mayflies and dragonflies, are also adapted to aquatic life.
The study suggests a fascinating connection between the first flattened projections on the thorax, evolving into wings, and their potential origin as respiratory organs, akin to the observed wing pads in the fossils. These discoveries contribute valuable insights into the evolutionary journey of winged insects, raising intriguing possibilities about their aquatic beginnings.