Since a major morphological difference exists between feathers and scales, a large number of functional transitional forms must have existed. Brush even concludes that feathers must have evolved from a conical shaped, tubercle-like follicle rather than a plate-like structure. Therefore, the complex follicular mechanism must have evolved first.
Furthermore, feathers have many more similarities, both morphologically and biochemically, to hair than scales. Hair-to-feather evolution is actually the most logical theory for many reasons, including the fact that a hair follicle already exists. The major argument against this theory is that birds are speculated to have evolved from reptiles, not from mammals. Therefore, most all researchers have totally ignored the hair-to-feather theory. This example is a fully developed semiplume that is located at the margin of feather tracts and the apteria the naked spaces between the feathered areas of birds and usually is overlain by the contour feathers.
The rachis and barbs were perfectly formed, and it sometimes is possible to identify the bird from which the amber-entombed feather has come. Unfortunately, many specimens have not yet been carefully studied.
One that was identified was from a Pididae woodpecker. Further studies no doubt will aid in the identification of many others. Although many fossil feathers and amber-preserved feathers some dating back to the Cretaceous have been located, no clues of feather evolution have ever been found in the fossil record—and consequently no physical evidence exists of the many changes that feathers must have undergone if they evolved.
Millions of fossil birds exist in the fossil record, and all of them have perfectly formed feathers. For this reason, feather origin is considered an enigma by Darwinists. A major problem with all Darwinistic theories of both feather and bird evolution is the fact that functional integrity is required for life, just as it is for any complex machine, involving not only the feather but also its many support structures including the follicle, muscle, and nervous systems. In other words. Flight requires not only the evolution of feathers, but also a total redesign of almost the entire animal.
As an evolutionary respiratory physiology expert at Oregon State University in Corvallis, argues:. However, the apparently steadfast maintenance of hepatic-piston diaphragmatic lung ventilation in theropods throughout the Mesozoic poses a fundamental problem for such a relationship. The earliest stages in the derivation of the avian abdominal airsac system from a diaphragmatic-ventilating ancestor would have necessitated selection for a diaphragmatic hernia [i.
Such a debilitating condition would have immediately compromised the entire pulmonary ventilatory apparatus and seems unlikely to have been of any selective advantage. This was in the context of the fashionable theropod origin of birds, but it seems to an equally effective criticism of all reptile-to-bird origin theories.
It is still much too early to evaluate the numerous recent claims of feathers on dinosaurs or other animals, some of which have been shown to be forgeries. Others also may prove to be forgeries, while some may offer very debatable evidence for feather evolution. They have birdlike teeth and lack the long tail seen in theropods. Caudipteryx even used gizzard stones like modern plant-eating birds, but unlike theropods. Far from being ancestors of Archaeopteryx, cladistic evidence points under evolutionary presuppositions to their being birdlike under their own transforming paradigm , and secondarily flightless descendants of Archaeopteryx.
Other new discoveries—such as the hair like filamentous integumental appendages on Sinornithosaurus millenii , a non-avian dinosaur—have only complicated the Darwinian theory such as discussed by Zhang and Zhou Even though fossil impressions of feathers are abundant in the fossil record, and much has been written speculating on how scale-to-feather evolution could have occurred, not a shred of fossil or other evidence has ever been found to support the scale-to-feather evolution theory. The profound evolutionary enigma of feathers noted by Darwin 76 and Heilmann 77 remains, even today.
The lack of evidence for feather evolution is not only a major problem for Darwinism, but the design and function of feathers provides evidence for both intelligent design and irreducible complexity. Periodically, new bird fossils are found, but most of them have been of little or no use as evidence of bird evolution, and the few claimed examples typically generate much debate.
For instance, Feduccia concluded that one recent find, known as Apsaravis , contributes little.
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If Apsaravis is not related to any modern ornithurine, how can it tell us anything important about the evolutionary questions raised by [its discoverers] Norell and Clarke? Much debate exists about this and related finds. Conclusions on these finds will require much more study, and yet already have produced much debate and controversy. Much disagreement still exists about Archaeopteryx , a discovery now around years old. Likewise, the place in evolution, if any, of the recent finds may never be settled.
Many of these finds are from a province of China, and already one find from this area has proven to be a hoax. Consequently, much more study is necessary to determine the value of these finds. So far, none of these finds challenges the conclusions presented in this paper, and early study of these finds has strongly supported the findings reviewed here.
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An electron micrograph of a flight feather. The hook of the barbules can clearly be seen. Courtesy David Menton. The detailed structure of the feather above and scales below both magnified 80 times. Our Planet. Earth Optimism Summit.
Birds of a Feather: Tales of a Wild Bird Haven
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Black Feathers: Dark Avian Tales: An Anthology
Video Contest. How they are used by birds can be unique too. If you think to yourself, you can probably come up with maybe a half dozen to a dozen ways feathers are used by birds. To be sure, you will have missed a few feather functions. Let's go through 23 ways birds can use their feathers. Downy feathers as well as semiplume feathers are able to trap pockets of air close to the bird's body to help keep it warm.
How much body heat they keep can be adjusted by arranging their feathers to trap more or less air. If you see birds fluffing their feathers in the cold, that is their way of adding extra air to trap body heat and stay warmer. The strong and ridged contour feathers shield birds from wind.