MANTI5
10+ year member
CarAudio.com Elite
"Muscular wings beating for hours or even days in flight generate much heat, yet, without sweat glands for cooling, the bird copes with the problem—it has an air-cooled “engine.” A system of air sacs reach into almost every important part of the body, even into the hollow bones, and body heat is relieved by this internal circulation of air. Also, because of these air sacs, birds extract oxygen from air much more efficiently than any other vertebrate. How is this done?
In reptiles and mammals, the lungs take in and give out air, like bellows that alternately fill and empty. But in birds there is a constant flow of fresh air going through the lungs, during both inhaling and exhaling. Simply put, the system works like this: When the bird inhales, the air goes to certain air sacs; these serve as bellows to push the air into the lungs. From the lungs the air goes into other air sacs, and these eventually expel it. This means that there is a stream of fresh air constantly going through the lungs in one direction, much like water flowing through a sponge. The blood in the capillaries of the lungs is flowing in the opposite direction. It is this countercurrent between air and blood that makes the bird’s respiratory system exceptional. Because of it, birds can breathe the thin air of high altitudes, flying at over 20,000*feet for days on end as they migrate thousands of miles.
Other features widen the gulf between bird and reptile. Eyesight is one. From eagles to warblers, there are eyes like telescopes and eyes like magnifying glasses. Birds have more sensory cells in their eyes than have any other living things. Also, the feet of birds are different. When they come down to roost, tendons automatically lock their toes around the branch. And they have only four toes instead of the reptile’s five. Additionally, they have no vocal cords, but they have a syrinx out of which come melodious songs like those of the nightingales and mockingbirds. Consider too, that reptiles have a three-chambered heart; a bird’s heart has four chambers. Beaks also set birds apart from reptiles: beaks that serve as nutcrackers, beaks that filter food from muddy water, beaks that hammer out holes in trees, crossbill beaks that open up pinecones—the variety seems endless. And yet the beak, with such specialized design, is said to have evolved by chance from the nose of a reptile! Does such an explanation seem credible to you?"
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"At one time evolutionists believed that Archaeopteryx, meaning “ancient wing” or “ancient bird,” was a link between reptile and bird. But now, many do not. Its fossilized remains reveal perfectly formed feathers on aerodynamically designed wings capable of flight. Its wing and leg bones were thin and hollow. Its supposed reptilian features are found in birds today. And it does not predate birds, because fossils of other birds have been found in rocks of the same period as Archaeopteryx."
In reptiles and mammals, the lungs take in and give out air, like bellows that alternately fill and empty. But in birds there is a constant flow of fresh air going through the lungs, during both inhaling and exhaling. Simply put, the system works like this: When the bird inhales, the air goes to certain air sacs; these serve as bellows to push the air into the lungs. From the lungs the air goes into other air sacs, and these eventually expel it. This means that there is a stream of fresh air constantly going through the lungs in one direction, much like water flowing through a sponge. The blood in the capillaries of the lungs is flowing in the opposite direction. It is this countercurrent between air and blood that makes the bird’s respiratory system exceptional. Because of it, birds can breathe the thin air of high altitudes, flying at over 20,000*feet for days on end as they migrate thousands of miles.
Other features widen the gulf between bird and reptile. Eyesight is one. From eagles to warblers, there are eyes like telescopes and eyes like magnifying glasses. Birds have more sensory cells in their eyes than have any other living things. Also, the feet of birds are different. When they come down to roost, tendons automatically lock their toes around the branch. And they have only four toes instead of the reptile’s five. Additionally, they have no vocal cords, but they have a syrinx out of which come melodious songs like those of the nightingales and mockingbirds. Consider too, that reptiles have a three-chambered heart; a bird’s heart has four chambers. Beaks also set birds apart from reptiles: beaks that serve as nutcrackers, beaks that filter food from muddy water, beaks that hammer out holes in trees, crossbill beaks that open up pinecones—the variety seems endless. And yet the beak, with such specialized design, is said to have evolved by chance from the nose of a reptile! Does such an explanation seem credible to you?"
---------- Post added at 01:00 AM ---------- Previous post was at 01:00 AM ----------
"At one time evolutionists believed that Archaeopteryx, meaning “ancient wing” or “ancient bird,” was a link between reptile and bird. But now, many do not. Its fossilized remains reveal perfectly formed feathers on aerodynamically designed wings capable of flight. Its wing and leg bones were thin and hollow. Its supposed reptilian features are found in birds today. And it does not predate birds, because fossils of other birds have been found in rocks of the same period as Archaeopteryx."
