Science » Planet Earth
Author`s name Dmitry Sudakov

History of aviation repeats history of evolution of birds

The first birds are thought to have descended from the predatory dinosaurs. Many a paleontologists had supported the theory but with some reservations. At the beginning, scientists could not explain what had prompted dinosaurs to explore the third dimension. More importantly, scientists could not explain how dinosaurs had actually got off the ground. Some theories maintained that the original flying dinosaur, the one who developed feathers to keep its body warm in freezing temperatures, had suddenly risen in the air while swinging its front paws frantically as it ran across the ground. The creature enjoyed its flying experience, according to theories. A desire to fly became an instinct in the course of evolution.

Then several skeletons of dinosaurs were unearthed in the Chinese province of Luoyang. The “aerodynamic” feathers were discovered on the skeletons’ hind extremities. The find effortlessly put an end to the “fast take-off run theory” because no animal could have swung its hind extremities while running. Scientists came up with another theory instead. According to the new theory, microraptors i.e. minute dinosaurs who lived about one hundred million years ago were the first to take to the air. The tiny creatures are thought to have lived in the trees. They would hop from branch to branch by gliding through the air. Paleontologists made quite an effort trying to reconstruct the six skeletons found at the excavation site. The animals were very small but extremely predatory. The body of the animal was completely covered with feathers, and all of its four hind extremities had the plumage for aeronautical purposes. The animals would either glide by spreading the extremities or they would fly by flapping them rapidly like butterflies do. Those prehistoric “butterflies” were the size of a chicken or goose.

However, the beautiful theory was broken to smithereens following another discovery made in the same Chinese province of Luoyang. The skeleton of microraptor gui was found in a relatively pristine condition. It is believed that the species lived in the Cretaceous period about 125 million years ago.

Paleontologist Shankar Chatterji of the University of Texas did what should have been done in the beginning of any study involving aeronautics – he joined forces with aviation engineer and aerodynamics specialist Jack Templin. The team conducted a thorough examination of the skeletons found in 2003. As it turned out, there was no way the microraptor in question could have spread its hind extremities, which were built for moving back and forth only. However, the animal could have folded them in a way so that they might transform into the wings positioned parallel to the front “arms” and slightly beneath them. The configuration resembled that of the wings of a biplane often referred to as a “stack of shelves.” Besides, Chatterji and his collaborator gathered enough evidence to prove that in terms of aerodynamics the above lineup was a lot more effective than the arms and legs spreading out wide.

It is just amazing to see the history of aviation repeating the history of evolution step by step. The brothers Wright, U.S. aeronautical inventors, were nor aware of the circumstance while designing their biplane, an airplane with two set of winds, one above the other. The inventors were driven by necessity; they needed those four wings to create enough lift for the airplane. In terms of the lift, a feathered paw was far too weak a wing to fly, and therefore another pair was required.

In both case, a biplane proved to be ineffective from the point of view of evolution. It was eventually superseded by a monoplane. Not unlike a bird equipped with two wings, a monoplane uses its two wings (built slightly wider to meet the requirements) for flying across vast distances.

Evgeni Kurochkin, a head of laboratory of the Institute of Paleontology under the Russian Academy of Sciences, does not share the point of view by Chatterji and his collaborator. “Chatterji and Templin are fundamentally wrong talking about the microraptor gui as an excellent example of original biplane. The point is that the creature’s hind wings can never fold under its front ones. The hind wings are located way back on the rear part of the body. As a result, there’s a gap between the front and back planes. The teropoid dinosaurs i.e. microraptors belonged to the one line of evolution, while the real birds fell under the other line that evolved in a parallel way,” said Kurochkin, in an interview to Nezavisimaya Gazeta.

Kurochkin published an article in the journal Priroda (Nature) back in 2004. The article listed enough evidence to rule out any possibility for the microraptor to spread out its hind paws. “Just like before, no prophet is accepted in his country,” said Kurochkin and smiled wryly.

Nezavisimaya Gazeta

Translated by Guerman Grachev

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