The evolution of flight has baffled scientists for ages. Many theories have arisen in attempts to explain this marvelous phenomenon, but a new study suggests the evolutionary process may have begun much earlier than previously depicted. The common notion in circulation is the adaptive feather theory. This theory suggests that feathers became present as a by-product of evolution; rising from a mutation in set of genes that also code for hair and scales in other species. These genes, known as box-set-genes, have been mainly unaltered for millions of years. However, mutations have arisen over time, and as a result, feathers became available to early dinosaur-bird-like species. The bird evolutionary branch has two major extant divisions that biologists agree on. These are the ratites (flightless birds) and the neornithes (modern birds). The idea behind the rise of feathers is that they gave early bird species some benefit in either running faster, escaping prey, or attracting a mate. Which mechanism is unknown, possibly all of them, but fossil evidence suggests the presence of an ancient bird-like creature that had feathers not capable of flight. And so the adaptive flight theory is born.
A new study looking at elements preceding the evolution of flight, such as, arm length and body size, among earlier species of birds, suggest this process began much earlier than previously mentioned. A 2014 articles states, “Being small and light is important for a flyer, and it now seems a whole group of dozens of little dinosaurs were lightweight and had wings of one sort or another. Most were gliders or parachutists, spreading their feathered wings, but not flapping them”. This is an interesting idea and supports the adaptive feather theory. Often, evolution takes many steps, twists, and turns to produce an observable outcome. It's known that mutations in the genes coding for hair and scales gave rise to feathers, and adaptions in the morphology and functionality of arm length/ body size both are a major influence in the rise of flight. Researcher Mark Puttick stated, "We were really surprised to discover that the key size shifts happened at the same time, at the origin of Paraves," said Mr Puttick of Bristol's School of Earth Sciences. "This was at least 20 million years before the first bird, the famous Archaeopteryx, and it shows that flight in birds arose through several evolutionary steps."
Evolution is never as clear cut as it seems on paper. New fossil evidence, new studies, and predictions made based on previous studies/fossils help give insight into how life evolves. It is an ever-changing science that is subject to the latest research and discovery to guide us further. This newest development supports and complements previous theories regarding flight, as well as, provides new insight in an area previously not so well understood. It takes scientist challenging and comparing every aspect of nature, genetics, and development among species to get a clear cut picture of the evolution occurring. This newest studying is guiding us in the right direction of one day fully understanding the mysteries behind flight.
posted by Maxwell Liner (5)