Fossil Feather Finds

 How flight feathers evolved has long been a problem for evolutionists.  The current popular theory is that feathers evolved from a theropod dinosaur or “a shared common ancestor deeper in the past.” [1] This is often stated in the media, taught in schools, [2]   and highlighted in museums but this theory has many problems. Today, only birds have feathers; however, this may not have been the case in the past.   Recent discoveries in China’s Liaoning Province have found dinosaur fossils with what appeared to be feathers but may be just “frayed skin structural collagen.”  [3]   Also, in the same province, many fossils of birds have been found along with other feathered fossils that may be either dinosaurs or flightless birds. [4]   Although these discoveries have excited many evolutionists, they bring up more questions than answers.  Some evolutionists have even theorized that dinosaurs evolved from birds.  For those that do not believe in evolution, they have no reason to assume that birds were the only animals to be created with feathers. [5]   Evolutionists have many theories how bird flight came about. Again, they are just theories.  “For a flying bird to have evolved from a non-flying reptile, as the evolution theory proposes, almost every structure in the non-flying animal would require change.  There is no living or fossil evidence for this, and there is much against it.”  [6]

Scales and Filaments

How could a very complicated structure like a feather evolve?   Some “scientists sought to illuminate the origin of feathers by examining the scales of modern reptiles, the closest living relatives of birds.  Both scales and feathers are flat. So perhaps the scales of the birds' ancestors had stretched out, generation after generation. Later their edges could have frayed and split, turning them into the first true feathers.” [7] This theory has been largely discarded by scientists as scales and feathers have almost nothing in common.  Reptile scales, also called scutes, are folds or bumps of dead skin made of a keratin protein and some types incorporate bone.  Unlike scales, bird feathers are very complicated branching structures of a different type of keratin that grow in skin follicles and unfurl from a cylindrical sheath.  [8]    

One evolutionary source describes the evolution of feathers as follows:

“This complicated structure evolved in multiple stages over many millions of years.

STAGE ONE: thin, hollow filaments appeared over 150 million years ago.

STAGE TWO: tufts of filaments that somewhat resemble down feathers.

STAGE THREE: numerous filaments sticking out from a central shaft.

STAGE FOUR: shaft located off-center; these feathers provide the aerodynamic lift needed for flight.”  [9]

However, this evolutionary scheme involves the logical fallacy of circular reasoning.  Unless one believes the premise that feathers evolved, none of the four stages are valid (e.g., finding hollow filaments does not prove they evolved or that they evolved into something else). 

Types of Feathers

The two basic types of feathers are down and contour.   Down feathers are closest to the body and provide insulation and a soft cushion.  Contour feathers are the outside feathers we normally see, and they provide water proofing, protection, insulation, aerodynamic shape and color to birds.   Flight feathers are contour feathers and are generally the largest feathers with those on the wing called remiges and the tail feathers called rectices.   Remiges provide the lift and thrust necessary for flight. Rectices provide stability and turning.  Birds create drag for landing by repositioning their wing and tail flight feathers. 

Feathers Are Very Complex Structures

Although feathers and mammal hairs are formed by dermal papillae in skin follicles, feathers are far more complicated than hairs.   As each type of feather grows, its shaft extends outward through the skin.  Then, the portion of the shaft above the skin begins to dry and split allowing the feather to gradually unfurl.  In contour feathers, two vanes unfurl from the solid rachis, that portion of the central shaft above the skin.  In down feathers the rachis is completely or partially missing and there are no vanes just very flexible soft tangled barbs.   Below the skin the central shaft is called a quill and is hollow.   Each vane is made up of parallel barbs branching diagonally from the rachis.  For flight feathers, the outer (leading) vane is short and stiff, and the inner (trailing) vane is longer and more flexible; otherwise, oncoming air forces would tear apart the feather. [10]   The number of barbs varies depending on the kind of bird and the type and size of feathers.   For example, flight, covert and down feathers have numerous barbs, and bristle and filoplume feathers have only a few barbs.   Except for down, bristle and filoplume feathers, barbules branch out from the barbs. In flight feathers, the barbules cross over barbules from the adjacent barbs and are firmly linked to each other by microscopic hooklets so positioned that they will not unzip with wing down strokes.  A large flight feather will have hundreds of barbs and thousands perhaps millions of barbules and hooklets. This arrangement of a strong central shaft (offset for wings) and vanes made of barbs, barbules and hooklets produces a practically weightless, sturdy, almost airtight feather ideal for flight.   

All birds’ feathers overlap for aerodynamic, insulation, and waterproofing reasons and all feather tips point opposite to the direction of flight to reduce drag forces.   The number, size, shape and positioning of the flight feathers vary depending on the type of bird.   “Each feather along the length of the wing has a slightly different size and shape that is coordinated with all the others.” [11]    Each contour feather, including flight, is connected to a nerve and muscles that the bird precisely adjusts for aerodynamic and other purposes such as protection and insulation.   Wing flight feathers are all connected directly to the bone with ligaments to withstand the forces on them.   Tail feathers are connected to each other by ligaments and only the innermost feathers are connected to the tail bone.   “To generate lift, a bird merely needs to tilt its wings, adjusting the flow of air below and above them.” [12]   Twisting the tail feathers allows the bird to make precise turns.  

Flight not only requires flight feathers but other components such as precision control by the bird’s brain, a very light weight body, a strong skeleton with hollow strutted bones, special bones such as the furcula (wishbone) and keeled sternum, strong breast muscles for up and down strokes, etc...  For most flight birds, their skeletons weigh much less than their plumage.  

Preening

If the feathers become untidy, they can be easily re-zipped by the bird during a feather maintenance process called preening.  The bird simply runs the feather through its beak and thereby reconnects the hooklets between the barbules.   During this preening process, many kinds of birds will take oil with their beaks from a gland near the base of their tail and oil their feathers.  Oiling the feathers helps to keep them from becoming brittle and to waterproof them so the bird’s body can keep relatively dry and its feathers maintain their shape for flight after becoming wet.   “Because the(ir) forelimbs have little use beyond flight or swimming,” the bird’s long flexible “neck is crucial for the task of preening: the head must be able to reach most of its body to properly tend to feathers. While mammals have seven neck vertebrae, birds have eleven to twenty-five.”  [13] 

Feather Replacement

Feathers become worn and are replaced once or twice a year through a process called molting.  This is an orderly process whereby a few feathers are lost and replaced at a time.  In the case of flight feathers, they are lost in exact pairs with one from each wing and mirror positions on the tail.  This is important for balance in flight.   The feathers are pushed out by the new feathers.    If a feather is lost at other times, a new replacement feather will normally grow out in about two months.

Conclusion

Flight feathers are very complicated structures necessary for a bird to fly.   They are irreducibly complex structures and part of a larger irreducibly complex system that requires each part to meet certain specifications and to be present from the beginning to produce flight.   Irreducible complexity does not occur except from intelligent design.