A Flying Chance
Perryman2nd Place - Griswold Award
Evolution, in general, is still observed today. For example, the mystery behind the English peppered moth involves an evolution many did not notice. When Britain went through the Industrial Revolution, smoke from the factories created layers of soot across the land, making objects with lighter color easily discernible. The peppered moth originally was light fray and keenly camouflaged, with the exception of a small proportion of dark moths. After soot began blanketing the ground, birds could visually locate the moths and eat the,. When this occurred, the dark moths became fit for survival and dominated the soot-covered cities. A single gene coded for the dark color, spread by means of natural selection. Subsequent reduction of smoke pollution resulted in the decrease of the dark moth varieties ("Evolution"). In some cases, camouflage and other adaptations are essential for survival in an ever-changing world involving humans or other predators. Stages of evolution involve a smaller, primitive creature growing in size and shape as the creature thrives over thousands to millions of years. During this time of change, the species also grew to different sizes, from large, stalky brutes to average size dominating creatures to small, clever scavengers. Most species encounter this form of evolution, including humans and dinosaurs ("Evolution").
Over a 350 million-year span, dinosaurs grew from reptiles the size of small cats and dogs to huge reigning creatures. During this time, the Mesozoic Era, dinosaurs grew to different sizes, structures and capabilities to suit their environments. These creatures ranged from two-legged to four-legged land animals, to winged warriors of great size and smaller feathered scavengers, to marine reptiles and fish. In theory, many different types of ancient species, even through the hard times of mass destruction, survived to create today’s crocodiles, turtles and maybe even birds. One theory behind bird evolution suggests that birds at one time soared across the ancient lands of Pangaea, scavenging their food and maybe even walking on land, wingless ("How").
Pterosaurs were the first flying reptiles. Mistaken for flying dinosaurs, Pterosaurs were only distant cousins (Gore 27). This species considered of Pterodactyls, Pteronadons, Dimorphodons, Rhamphorhynchus and other similar winged reptiles. These creatures had sharp teeth and claws for grabbing and devouring prey. They ranged from the size of small dogs to the size of large vehicles ("Pterosaurs"). Pteronadons, one of the largest flying dinosaurs, more or less glided through flight because of their size and, in theory, used momentum or wind movement in this procedure. Though their wings were big and strong to help in flight, some forms of momentum could have helped them in lift off, as with a plane or hang-glider. Other Pterosaurs might have used this form of airlift, but because of less weight, may have been able to start flight like modern birds ("How"). Pterosaurs lived from the beginning of the Triassic Period to the end of the Cretaceous Period. The Pterosaurs that might have survived the meteor impact in time were unfit to live through the thick atmosphere, radiation, acid rain and disease that ruled the land for hundreds of years ("Pterosaurs").
The first feathered creature was a type of Theropod, about the size of a crow that lived in the Jurassic Period. This creature was known as Archaeopteryx ("Dinosaur"). These flying reptiles scavenged like crows and also fed on smaller rodents and lizards at that time. They were not rulers of the sky and succumbed to larger predators. In speculation, these Theropods were not the swiftest of flyers, in comparison to many forms of Pterosaurs. Paleontologists think they struggled into flight, often unable to control their movements in the sky, like young birds just learning how to fly. Their clumsiness made them vulnerable ("How"). The length of their existence is unknown (Gore 18, 19). Their connection to birds dates in the late Jurassic period (Gore 29). Some scientists speculate their demise was much like the other dinosaurs; others theorize the possibility of evolution shaping these creatures’ existence. Germans unearthed the first fossilized Archaeopteryx for the Smithsonian National History Museum in Washington D.C. There, the fossil is kept under a separate lock and key for protection as one of the most important fossils ever found (Gore 28). "A visiting Japanese professor I brought down here actually fell on his knees in awe," says paleontologists Milner. "The individual feathers are preserved in minute detail," says Milner. "Without them most people would have interpreted this as a small dinosaur. Actually it’s quite possible some dinosaurs had feathers, too" (Gore 28).
Theropods were carnivorous and ranged in size from ten centimeters to ten feet long and more. This species of dinosaurs consists of many forms and characteristics. The most common traits include bipedal movement, having arms smaller or thinner than legs, for grasping and clawing, many sharp teeth, and eyes capable of pinpointing depth and movement, traits uncommon in Tyrannosaurs. Most Theropods were pack-hunters, including Velociraptor and Deinonychus ("Dinosaur"). Theropod body structures are common to today’s birds and probably moved similarly when walking. The only structure not common with birds is the pubic bone. A Theropod’s pubic bone projected forward, and it only later developed deflected pelvic bones, as with the majority of dinosaurs (Gore 17). Paleontologists think the featherless Theropods could have also flown if they had wings ("How").
Other dinosaurs did have bird-like hips with the pubic bones parallel with the other pelvic bones. Ornithopods, Stegasaurs, Anklysaurs, Cerratopsians, Packycephalosaurs and Fabrosaurs have this trait (Gore 17-19). Ornithopods, in particular, were two-legged and four-legged herbivores having, in most cases, duck bills or beak-like mouths (Gore 19, 29-33). In theory, the smaller bipedal ornithischians could have attempted to fly using the ground-up theory, the origin of flight, in which scientists believe momentum encouraged flight ability. For example, Ornithischians and Theropods could have been running across a field or plain when for a split second, maybe while flapping their arms, they were uplifted and might have flown if they had wings ("How"). Another example is of the Pterosaurs, who glided in air and may have used momentum for their movements. Other scientists hypothesize that dinosaurs could have flown easier might there have been denser air. The denser the air, the more abundant the hydrogen and oxygen and the easier flight can occur. Theropods could have used this to their advantage ("How").
Though many species of dinosaurs might have had the ability, body structure or practice for flight, like Pterosaurs, Archaeopteryx is the only type that completely succeeded to continue life past the dinosaur age. Archeologists in China found the only link between Archaeopteryx and modern birds. Sinornis was a seven-inch flying creature having both reptilian and bird traits. Sinornis had tiny teeth and claws for catching and eating insects and other creatures small enough to fit into its mouth. They also had body structures similar to pigeons. Sinornis had the scavenging ability and size to withstand the difficulties that killed so may other species (Gore 19).
On the other hand, some scientists say that since these primitive feathered creatures had sharp teeth, then the trait holds a mystery of why modern birds do not have teeth. This observation gives scientists a reason to believe that dinosaurs did not evolve into birds. For a while these observations held up, until recently, when scientists inserted dentine into the embryo of a bird. As the egg developed, a tooth formed on the beak of the bird, showing that the genetic roots give evidence of tooth creation, meaning that birds have the genetic capability to form teeth but at one time lost the elements that teeth formed from, like dentine ("How").
Although a great number of paleontologists link birds to dinosaurs, others have their own contradictions to the theory. One contradiction is the convergent evolution statement, which postulates that completely different creatures are similar only in appearance. An example would be the comparison between dolphins and Ichthyosaurs. They both look similar, having fins and long "bottle nose" snouts, but dolphins are mammals while Ichthyosaurs are ancient fish ("How").
Throughout all contradictions and misleading theories, evolutionists can still say that Archaeopteryx evolved from a small Theropod into a clumsily flying scavenger and through millions of years of more evolving turned into a creature capable of surviving harsh environments. After many other species went extinct, this creature thrived to form into today’s bird. The other scavengers, mammals, that at one time scurried out of sight of the reigning dinosaurs, were to become the new dominant species. Trial and error was the motto for many forms of species millions of years ago as the larger dominant creatures met their fates while the smaller scavenging creatures survived and created new lines of species to, in-turn, dominant the world.
Works Cited
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Gore, Rick. "Dinosaurs." National Geographic. January 1993: 2-53.
"How Dinosaurs Could Fly." Sci Trek. Prod. Discover Networks. Discovery
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