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Originally posted by dave420
Can anyone propose a decent experiment that can attempt to prove/disprove the whole rods phenomena? One that both sides, the believers and the rational, can agree on?
Originally posted by neuralfraud
In one of Mr. Escamilla’s videos I reviewed, I noticed a sequence in which he captioned the shot as being "60 fields per second" (this is accurate as NTSC is about 60 fields per sec.)
Exactly that's the point. Isn't the absence of the godfather of entomology, the "Einstein" of the world of Entomology in a public wiki a little bit suspicious ?
Science 23 October 1998:
Vol. 282. no. 5389, pp. 599 - 601
DOI: 10.1126/science.282.5389.599
Prev | Table of Contents | Next
News of the Week
PALEOBIOLOGY:
Insect Wings Point to Early Sophistication
Gretchen Vogel
Catching mosquitoes is no easy way to make a living. In pursuit of their darting prey, modern dragonflies hover, fly backward, and zoom around in tight high-speed turns. To execute these aerobatic maneuvers, the insects come equipped with highly engineered wings that automatically change their shape in response to airflow, putting the designers of the latest jet fighters to shame.
But in evolution, such engineering tricks are apparently old news. In a report on page 749 on a 320-million-year-old dragonfly from Argentina, entomologist Robin Wootton of the University of Exeter in the U.K. and his colleagues describe evidence for a complex airfoil, a structure that forces air to move faster over the top of a wing than underneath it, creating a pressure difference that gives a wing its lift. Not only did evolution come up with such sophisticated flying adaptations very early, but it also produced them more than once. Although the ancient fossil structures have the same effect as the airfoils of modern dragonflies, they are different enough that scientists think the two systems evolved independently. "It's a startling example of convergent evolution," says evolutionary aerodynamicist Adrian Thomas of Oxford University in the U.K.
To achieve the airborne agility needed to chase prey such as mosquitoes and houseflies, a dragonfly must be able both to twist its wings and change their shape to alter the airflow around them. Unlike birds and bats, which have muscles that control the shape of their wings, an insect wing is simply a membrane stretched over a series of veins. But in an example of what Wootton calls "smart engineering," modern dragonflies have a complex system of veins that stabilize and shape the wings without any muscle power. One region, called the basal complex, forms a series of pleats arranged so that when the insect flaps downward, the air pressure on the underside of the wing forces the trailing edge to stiffen and curve down in a classic airfoil shape. Roughly similar to the flaps that open on planes during takeoff and landing, the mechanism allows dragonflies to stay aloft at lower speeds.
Wootten and paleoentomologist Jarmila Kukalová-Peck of Carleton University in Ottawa noticed a region similar to the modern basal complex as they examined a well-preserved, 8-centimeter dragonfly from La Rioja, Argentina. When Wootton, an expert on the mechanics of insect wings, made a three-dimensional paper copy of the wing region, it responded to a force on the underside of the wing--similar to the force of air as a dragonfly flaps its wings downward--in the same way as the modern dragonfly's. The authors propose that the structure played a similar role in the ancient insects, allowing them to get more efficient lift from a downstroke. Thomas agrees. "I made the cardboard models" from their diagrams, he says, "and they work in exactly the same way" as the modern basal complex.
Despite the similarity in function, it seems that the two designs arose independently. They use different sets of veins, and the modern basal complex forms a triangle while the fossil one is a parallelogram. In addition, the wings are attached to the body of the fossil insect differently than those of modern dragonflies, and the researchers believe it was a cousin to, not a direct ancestor of, insects alive today.
Dating from only 10 million years after the oldest known flying insect, the specimen shows how quickly insects evolved sophisticated aerodynamic engineering, says insect flight physiologist Robert Dudley of the University of Texas, Austin. Still, there has been some improvement over the eons. The Argentine fossil is missing another aerodynamic feature present in modern dragonflies--a stabilizing structure called the node, which helps the wings withstand stresses from the twisting required for hovering in place. That may have evolved, Wootton says, as dragonfly prey itself became more aerodynamically adept--adaptations that anyone who has chased a mosquito can appreciate.
Originally posted by angst18
Think I saw someone post about a Robin J. Wootton, don't know if they posted a link, but here it is:
www.biosciences.ex.ac.uk...
Guess the J. could stand for Jon.
Originally posted by Jose Escamilla
So I know I'm insane what's your explanation for being ignorant?