A new study conducted by the scientists at Marine Biological Laboratory (MBL) in Massachusetts has revealed that the wings of the insects have evolved from a random outgrowth on one of the legs of their crustacean ancestors that moved to land 300 million years ago.
As per the researchers, the legs of the crustacean ancestors were pushed back into the body gradually when the creature moved from sea to land, reported Daily Mail.
The new study published in Nature Ecology & Evolution says that these leg lobes gradually expanded in order to enable gliding and controlled descent from falling. It later formed movable insect wings.
For the purpose of this study, these researchers used gene-editing tool CRISPR-Cas9 along with clues from 19th century scientific papers. They did this to work out the differences in leg segments that led to the evolutionary change.
This new research builds on a 2010 discovery that said that insects evolved from crustaceans. First author of the research, Dr Heather Bruce informed that arthropods legs are composed of segments and separated by flexible joints so they can move. Dr Heather said, “These segments are patterned in the embryo by leg-patterning genes, including the ones I studied in the paper.”
However, she also said that because insects evolved from crustaceans millions of years ago, they do not have access to the last common ancestor of parhyale and insects. Therefore, they have used parhyale to represent the features that they are interested in because insects and parhyale are cousins and the latter is also a crustacean.
The segmented legs of common fruit fly drosophila and the beetle tribolium were compared with that of parhyale's segmented legs. Heather said that crustacean and insect leg segments are in alignment.
According to her, they correspond to each other in a one-to-one fashion. She noticed though that crustaceans had two more leg segments than the insects. Speaking about the research, director of MBL, Nipam Patel said that what is being realised with genomic comparisons is that nothing is brand new and everything came from somewhere.