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.
__________________________
[1] Zimmer, Carl, Feather Evolution, National Geographic Magazine, Feb. 2011, 2 http://ngm.nationalgeographic.com/2011/02/feathers/zimmer-text/2
[2]The Origin of Birds, Understanding Evolution, Evolution 101, University of California Museum of Paleontology, viewed April 25, 2015,
http://evolution.berkeley.edu/evolibrary/article/evograms_06
[3] Sarfati, Jonathan, ‘Feathered’ dinos: no feathers after all! Creation Ministries International, 2012, http://creation.com/feathered-dinosaurs-not-feathers
[4] Oard, Michael, Did birds evolve from
dinosaurs? Creation Ministries International, viewed April 25, 2015, http://creation.com/bird-evolution
[5] Sarfati, ibid.
[6] Doolen,
Robert, Created to fly! Birds can fly, why can’t I? Creation Ministries International, originally published 1994, http://creation.com/created-to-fly
[7]
Zimmer, 1 http://ngm.nationalgeographic.com/2011/02/feathers/zimmer-text/1
[8] Feather Evolution, BIO
554/754, Eastern Kentucky University, viewed April 25, 2015, http://people.eku.edu/ritchisong/feather_evolution.htm
[9] Figuring Out
Feathers, The American Museum of Natural History, viewed April 25, 2015, http://www.amnh.org/exhibitions/past-exhibitions/dinosaurs-ancient-fossils-new-discoveries/liaoning-diorama/figuring-out-feathers
[10]
Zimmer, ibid.
[11] God of Wonders, DVD, (Eternal Productions, 2010), www. eternal productions.org
[12] Zimmer, ibid.
[13] Scott, Dave,Bird Skeletons & Avian Physiology, Nature Skills, 2011, http://www.natureskills.com/birds/bird-skeletons/