Anannya Roy, Amity University Kolkata
Who soared the empty skies 360 million years ago?
Not the Pterosaurs. Not the Birds. Definitely not the Bats.
They were the Insects. They flew before anything else did. The origin of wings among these tiny arthropods was however an enigma, it bugged the Scientists for over a Century. There were many theories, in many textbooks but no proper conclusion; until very recently.
It was discovered that insect wings evolved from the outgrowths or “Lobes” on the legs of ancestral crustaceans. Centuries back when this marine organism left the oceans to find a new home on the land, everything changed. The leg segments closest to its body, became incorporated into its body wall during embryonic development to better support its weight on land. These lobes moved up the insects back and formed the wings. Initially it came off as a bit of a surprise- insects and crustaceans? But in this circle of life, we all are connected.
Insects were always grouped with the Myriapods, consisting of millipedes and centipedes. Researchers spent years analyzing these organisms in order find something that would give them insights into the origin of wings, to come up with a satisfactory conclusion. When they found nothing, they suggested that Wings were a “Novel” phenotype-A gift of Evolution. They reached the top of the ladder, but it was leaning against the wrong wall.
According to Genetic analysis, insects were more closely related to the Crustaceans that to the Myriapods.
Heather Bruce and Nipam Patel from Marine Biological Laboratory (MBL), Woods Hole, used CRISPR-cas 9 gene editing technology to disable five sharing leg-patterning genes in Parhyale, a crustacean and the fruit fly, Drosophila. Results showed that these genes corresponded to 6 leg segments farthest from the body. But in the Parhyale, there was a 7th leg segment, very close to its body which was clearly absent in Drosophila. This proved the stated theory.
CRISPR cas-9 gene has enormous potential, if used wisely. It is the future of Biotechnology and genetic engineering. Just the way studying the past helps us predict the future, investing in this technology of the future, will help us decode the mysteries of the past lurking above our heads.
Also read: NANOPARTICLES IN THE SYNTHESIS OF ANTICANCER DRUGS
Citation
Knockout of crustacean leg patterning genes suggests that insect wings and body walls evolved from ancient leg segments https://www.nature.com/articles/s41559-020-01349-0
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