Journal Entry 1 Wing Evolution
Wing evolution has been a highly debated topic in insects. Wings play a crucial role for insects since they are used to assist with collecting food, migration, fleeing from predators, and many other activities. There are three main theories that have been thoroughly researched to help explain the evolution of wings. These theories include the paranotal origin of wings, the tracheal gill theory, and the exite-endite theory.
The paranotal origin of wings hypothesis states that wings developed from paranotal lobes. When insects fell on the ground, nobes first acted like a parachute so the insect can land swiftly on its feet and scurry away from predators. As nobes grew larger they developed from gliders into wings. The main evidence behind this theory is the presence of broad thoracic nota and wing like prothoracic lobes on fossils of Ephemeroptera, Palaeodictyoptera and Protorhoptera that show venation and articulation (Whitfield 324).
The tracheal gill hypothesis postulates that wings developed from tracheated gills since both were thin, membranous and mobile. Gills first started off for being used for breathing in oxygen, then used as fins to promote locomotion, and finally modified the spiracles which reduced water loss to permit gliding which eventually turned into flying. Wiggleworth supported this theory by stating that wings and legs could be found in the thorax if it was originated by exites (Whitfield 325).
The exite-endite hypothesis proposes Kukalova-Peck’s theory about wings developed from exites that were found on many leg bases of early insects. Later, it was found that those insects also had endites. This theory was supported by the fact that wings are originated from a structural feature that already had the necessary muscles, tendons and appendages of insects. This was later proven by the dismissal of Manton’s theory that insect’s legs are different than other arthropods legs (Whitfield 326).
I believe that the exite-endite theory seems the
The paranotal origin of wings hypothesis states that wings developed from paranotal lobes. When insects fell on the ground, nobes first acted like a parachute so the insect can land swiftly on its feet and scurry away from predators. As nobes grew larger they developed from gliders into wings. The main evidence behind this theory is the presence of broad thoracic nota and wing like prothoracic lobes on fossils of Ephemeroptera, Palaeodictyoptera and Protorhoptera that show venation and articulation (Whitfield 324).
The tracheal gill hypothesis postulates that wings developed from tracheated gills since both were thin, membranous and mobile. Gills first started off for being used for breathing in oxygen, then used as fins to promote locomotion, and finally modified the spiracles which reduced water loss to permit gliding which eventually turned into flying. Wiggleworth supported this theory by stating that wings and legs could be found in the thorax if it was originated by exites (Whitfield 325).
The exite-endite hypothesis proposes Kukalova-Peck’s theory about wings developed from exites that were found on many leg bases of early insects. Later, it was found that those insects also had endites. This theory was supported by the fact that wings are originated from a structural feature that already had the necessary muscles, tendons and appendages of insects. This was later proven by the dismissal of Manton’s theory that insect’s legs are different than other arthropods legs (Whitfield 326).
I believe that the exite-endite theory seems the