The Origin of Wing Design in Species ST 565 April 15, 2016 Outline

Theories of Flight Insects Dinosaurs Birds and Bats Man's Inception of Flight References

Proposed Theories

Cursorial- (Trees-Down Theory) flight apparatus were adapted to improve hunting by lengthening leaps and improving maneuverability. Aborneal- (Ground-Up Theory) locomotion of animals in trees. Habitats pose numerous mechanical challenges to animals moving through them, leading to a variety of anatomical, behavioral and ecological consequences (e.g. rock piles or mountains).

Why Did Flight Evolve? Escape from predators. Catch flying or speedy prey. Move from place to place (leaping or gliding). Hindlegs for use as weapons. Access to new food sources or an unoccupied niche.

Insects

Over ~330 MA. Gill-like apparatus (earliest insects).  Supplanted in the adults by tracheae, to form little flaps.  Proto-wings would have been useful for little more than jumping, perhaps adding a little to the distance over which an insect could leap.  Gradually these wings would have grown larger, until they could be used for controlled diving, gliding, and then even flapping flight (Megasecoptera ~1m wing span).  Most modern insects have functional wings as adults. Insects: Stoneflies

Modern stoneflies walk on the surface of water, and raise their rudimentary wings if they feel a puff of air. Propelled across the water by the breeze. Some species even stand on their hind limbs and flap their wings as they sail. Sailing sufficient potential to drive the evolution of insect wings in the past. Aerodymanics of Insect Flight

A. The wing section is depicted by a segment drawn perpendicular to a line joining the wing base and wing tip (wing chord), connects the leading edge (filled circle) to the trailing edge. B. Sectional view of the insect wing. The free-stream velocity is denoted by U`,(free stream velocity) and U∞ (downwash velocity). The geometric angle of attack (a) is the angle that the wing section makes with U`. C. Wing pronation occurs dorsally as the wing transitions from upstroke to downstroke, and wing supination occurs ventrally at the transition from downstroke to upstroke (kinematics). D. Both wing tip and base translate at the same velocity, whereas in a flapping translating wing E. The tip rotates around an axis fixed to the base.

Sanjay, S. (2003) Dinosaurs: Pterosaurian Flight  First vertebrates to evolve true flight were the pterosaurs (flying reptiles c. 225 MA).  Pterosaurs were definitely proficient flyers, and were no evolutionary failure; as a group they lasted about 140 million years (birds ).  Derived from a bipedal, cursorial (running).  Size ranged from sparrows to small airplanes.  Pterosaurs are not closely related to either birds or bats (classic example) of convergent evolution.  Convergent evolution- organisms evolve structures that have similar (analagous) structures or functions in spite of their evolutionary ancestors being very dis- similar or unrelated.  Examples: Wings of bats and birds, eyes of octopus and squid (cephalopods), flippers of a whale and fish.

Pterosaurian Gross Anatomy Pterosaur wing (upper right) supported by an elongated fourth digit (pinky finger) several feet long). Pterosaurs had other flight adaptations such as a keeled sternum (lower right) for the attachment of flight muscles, a short and stout humerus, and hollow but strong limb and skull bones. Pterosaurs also had modified epidermal structures that were wing- supporting fibers, and others hairlike structures to provide insulation. Pterosaurs also had a bone unique to their species (pteroid bone). It pointed from the wrist towards the shoulder, supporting the wing. Evolution usually co-opts bones from old functions and structures to new functions and structures (not to reinvent the wheel). Avian Flight: Birds  Late Jurassic Period (c. 150 MA)  Most diverse group of flyers to evolve.  Birds show unique flight adaptations (e.g. hummingbird to albatross)  Archawopteryx (early ancestor, origin for bird flight) .  True flyer although not as skillful as modern birds (no wrist bones, flat/keeled sternum).  Confusiusornis or Sinornis evolved flight structures rapidly, analogous to modern birds.

Avian Gross Anatomy Birds adaptations similar to those of pterosaurs: hollow but strong bones, keeled sterna (lower left) for flight muscle attachment, short and stout humeri, and feathers. Bird wing (right) is supported by an elongated radius, ulna, and modified wrist bones, a fused clavicle (furcula, wishbone), which serves as a brace during the flight stroke. Phalanges of the bird wing for modern birds have only the second digit of the hand present (end of wing). The flight stroke more rigid and pronounced. Nonflying birds: penguins and ostriches, use the same basic flight stroke to fly under water and move across land. • Bat (Chiropteran Flight) c. ~50-60 MA (Eopene Epic) Second most diverse group and only mammals ever to evolve true powered flight. Evolved true flight from a gliding arboreal ancestor, using the membrane as a "net" while the flight stroke evolved. Fossil analyses indicate that bats are most closely related to the Cynocephalus, flying lemur). Distinctive feature- membrane of skin that extends between their limbs. Glide long distances between trees.

Chiropteran Gross Anatomy Bat wing (right) is a membrane supported by the arm and greatly elongated fingers of the hand, which support the distal part of the wing (thrust). Flight adaptations include echolocation (biosonar), keen senses, modified pectoral girdle (lower right), reduced radius, large humerus and ulna, clawed fingers and membrane stretched between the hindlimbs that helps to stabilize the bat during flight, and to capture prey. A new bone, the calcar, supports the membrane from the heel (analogous to the pteroid bone in pterosaur forelimbs). •Man's Myths of Flight Greek Legend - Pegasus Bellerophon the Valiant, son of the King of Corinth, captured Pegasus, a winged horse. Pegasus took him to battle with the triple headed monster, Chimera.

Icarus and Daedalus Daedalus was an engineer who was imprisoned by King Minos. Icarus, his son and he made wings of wax and feathers. Daedalus flew successfully from Crete to Naples, but Icarus, tired to fly too high and flew too near to the sun. The wings of wax melted and Icarus fell to his death in the ocean.

Alexander the Great Harnessed four Griffins, to a basket and flew around his realm. Man's Early Efforts China (c. 400 A.D.) Think about flying. Kites were used for ceremonies and test weather cond. Forerunner to balloons and gliders.

Hero of Alexandria Worked with air pressure and steam to create sources of power (aeolipile). L-shaped tubes on opposite sides of the sphere allowed the gas to escape, (thrust) to the sphere that caused it to rotate. Man's Early Efforts Leonardo da Vinci (Ornithopter,1480's) Conducted real studies of flight with over 100 drawings. Ornithopter design that showed how man could fly. Modern day helicopter is based on this concept.

Joseph and Jacques Montgolfier- Hot Air Balloon, 1783 Used smoke from a fire to blow hot air into a silk bag attached to a basket. The hot air then rose and allowed the balloon to be lighter-than-air. First passengers were a sheep, rooster and duck. It climbed to a height of about 6,000 feet and traveled more than 1 mile.

19th- 20th Century Otto Lilienthal (1891) Based on his studies of birds and how they fly, he wrote a book on aerodynamics that was published in 1889 Text was used by the Wright Brothers as the basis for their designs. Orville and Wilbur Wright (1903) Spent many years learning about all the early developments of flight. Read all the literature that was published up to that time and then began to test the early theories with balloons and kites.

Flight Today Humankind was now able to fly!

Many new airplanes and engines were developed to help transport people, luggage, cargo, military personnel and weapons.

20th century's advances were all based on this first flight at Kitty Hawk by the American Brothers from Ohio.

Man's ability to fly not possible without the evolution of flight by other species: insects, dinosaurs, birds and bats.

References

Brodsky, Andrew (1994). The Evolution of Insect Flight. New York: Oxford University Press. Burgers, P., and Chiappe, M. (1999). The wings of Archaeopteryx as a primary thrust generator. Nature, 399, 60-62. Chiappe, L.M. (1995) The first 85 million years of avian evolution. Nature, 378, 349-355. Chinsamy, A., and Elzanowski, A. (2001) Evolution of growth pattern in birds. Nature, 412, 402-403. Dudley, Robert. (2000), The Biomechanics of Insect Flight: Form, Function, Evolution. Princeton, NJ: Princeton University Press. Erickson, M., Rogers, C., and Yerby, A. (2001). Dinosaurian growth patterns and rapid avian growth rates. Nature, 412, 429-432. Marden, J. and Kramer, G. (1994). Surface-skimming stoneflies: a possible intermediate stage in insect flight evolution. Science 266, 427-430. Marden, J. (2004). How insects learned to fly. The Sciences 35, 26-30. Padian, K., Ricqles, J. and Horner, R. (2001). Dinosaurian growth rates and bird origins. Nature, 412, 405-408. Speakman, R., and Tomson, C. (1994). Flight capabilities of Archaeopteryx. Nature, 370, 514. Sadjay, S. (2003). The aerodynamics of insect flight. The Journal of Experimental Biology. 206 (3), 4191-4208. Unwin, D.M. (1998). Feathers, filaments, and theropod dinosaurs. Nature, 391, 119-123. Wong, K. (2002). Taking wing. Scientific American, 15(2).

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