Scientists have solved the mystery of the origin of wings in insects

Scientists have solved the mystery of the origin of wings in insects
Scientists have solved the mystery of the origin of wings in insects
Anonim

American biologists have determined how insect wings appeared. It turned out that in the distant crustacean ancestors of insects, as a result of evolution, the segments of the legs closest to the body became part of its outer shell. Later, these segments moved to the back and formed wings. Scientists have come to this conclusion as a result of genomic research.

Scientists at the Marine Biological Laboratory (MBL) at the University of Chicago (USA) have solved the mystery of the origin of wings in insects. This is reported in the journal Nature Ecology & Evolution.

It was possible to determine how the wings of insects appeared as a result of genetic research. According to the main author of the work, MBL researcher Heather Bruce, one of the reasons why this riddle could not be solved earlier was too late (around 2010) the recognition of the genetic relationship of insects and crustaceans.

“Earlier, based on morphology, everyone attributed insects to the superclass of millipedes, which also includes bipeds and labiopods. However, the study of centipedes does not provide an answer to the question of how insects formed wings. Therefore, the wings of insects were considered to be new structures that appeared in insects and have no analogues in their ancestors. And all because the researchers were looking for the ancestors of insects in the wrong place, - said Heather Bruce.

Heather Bruce and her colleagues argue that about 300 million years ago, the distant crustacean ancestors of insects left the sea on land, where, under the influence of new living conditions, they began to evolve. As a result, the segments of the legs closest to the body became part of the outer shell of the body itself, probably to make it easier for the creatures to balance. Further, these segments moved to the back, where they later formed wings.

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Insects have incorporated crustacean leg segments into their body, marked in red (7) and pink (8). The process on the leg segment (8) later formed a wing in insects © Heather Bruce

To prove their theory, the MBL scientists compared the leg segments of the small crustacean Parhyale with the leg segments of the fruit fly and beetle beetle. The study used the CRISPR-Cas9 method - "genetic scissors".

In all studied species, they identified and "turned off" common genes responsible for the formation of leg segments. However, the crustacean Parhyale was left with an additional seventh leg segment closest to the body, and scientists began to look for its tracks in insects.

In literary sources, Heather Bruce found a hypothesis put forward back in 1893 that insects included their proximal (closest to the body) part of the leg into the body composition. And then she discovered the theory of the 1980s, according to which these segments of the legs in insects subsequently moved to the back and formed wings.

“I was amazed that these old theories were confirmed in my genomic and embryonic studies,” summed up Bruce. In her opinion, the long-standing mystery would have been impossible to solve without modern genetic tools.

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