Thank you very much to everyone who submitted an entry to Competition 3: Evolution of flight! Here you can see some of the winning entries, as selected by our team of markers.
1st place (Year 10): Lili S
Lili’s winning entry
1st place (Year 11): Melanie H.
Melanie’s winning entry
The evolution of birds, and their ability to fly, would take millions of years from the appearance of the first feather, and involve the development of several other characteristics.
The first feathers did not even belong to birds as such – they are believed to have belonged to their ancestor, the Sinosauropteryx (a member of the theropods), evidenced by the tiny, hollow filaments on its fossil’s back and tail.
Initially, they would not even have been used for flight – rather, it is thought that the first feathers, which were short and hairlike, developed to provide insulation. As feathers continued to evolve, they would have served a variety of different functions. For instance, the preservation of melanosomes in the fossilised feathers of some theropods has allowed scientists to reconstruct their colour patterns, in turn suggesting that their tail feathers may have been used to attract mates, much like peacocks do today. The Anchiornis, a 150-million-year-old theropod whose abundant feathers formed a black and white spangled pattern, but were symmetrical and unsuited to flight, lends support to this theory. The asymmetrical feathers which allow for flight would also have likely served a different purpose at first, though exactly what is still uncertain. One hypothesis, supported by fossils of oviraptorosaurs found in the Gobi Desert, is that the long, asymmetrical feathers may have been used to shelter their nests and keep their eggs warm before they could be used for flight. Though it may be the case that some theropods such as dromaeosaurids were able to utilise such feathers to glide, there is not yet enough evidence to be certain.
Indeed, the development of wings would also have been necessary following the evolution of these asymmetrical feathers before flight became possible.
The joints needed to create the motions required for flight developed gradually – the first theropods had limbs with five digits, but as time passed, the fifth digit reduced in size and was lost altogether, after which the same happened to the fourth digit. Fossils of Archaeopteryx (which is perceived as the first bird) reveal that the second digit then elongated, and the wrist-bone took a semi-circular shape, allowing the joints to move as to create a thrusting motion and thereby render flight possible.
Other features would also have been needed to allow for flight to occur. One such feature is the furcula (or wishbone), which is found between the neck and breast of the bird, and is essential to provide support under the strain of flight. Theropods including the Archaeopteryx, but also ground-based theropods like the Tyrannosaurus, indeed had a furcula – another link between birds and their reptilian ancestors.
Since the Archaeopteryx, further evolution (e.g. the fusing of second and third digits, the thinning of bone walls, the growth of arms to support flight as the main form of movement, etc.) has continued to occur, making the process of flight more efficient and more resemblant of that of birds today.
2nd place (Year 10)
Safiyah M.