Amazing Animals
Text: Selected Scriptures
Any land-dwelling
mammal wishing to evolve into a whale could certainly practice moving its
left-right tail in an up-down fashion, and there is no doubt that it could
certainly improve up to a point. Maybe even learn to swim faster and catch more
fish. But after that its tail movement would begin to crush its reproductive
apparatus against its pelvis. This would have a tendency to lower the animal's
sexual urges somewhat and it would soon lose interest in reproduction -- not a
very positive evolutionary step. Taken to extremes, this new tail movement
would simply crush the whole pelvis. Such a transition would have no survival
value whatsoever. The selective pressures of the environment, or natural
selection, would work against any such change of tail on a land-dwelling mammal.
To make the
claim as evolutionists do that land-dwelling mammals evolved into sea-dwelling
whales is to claim that there had to be simultaneous accidental genetic changes
which allowed the tail to grow larger while the pelvis grew smaller. And all this
ignores the problems caused as the ever shrinking pelvis or hip bones reached
the point where they were far too small to support the creature's weight on its
hind legs, and yet still too large to let the animal move its tail up and down
with any efficiency.
Of course, tails
are not the only thing on whales that make them different from land-dwelling
mammals. To totally convert a land-dwelling mammal into a whale you would also
have to replace its sweat glands with thick layers of blubbery fat, change its
eyes so that the light rays under sea water are still brought to focus on the
retina, change its skin to produce a curious surface efficiently designed to
streamline the flow of water, and also find some way to enable it to give birth
to young which suckle under water without drowning, a rather essential
'adaptation.'
In other words,
if you wanted to make a tail for a whale you could not do it by using
evolutionary random chance small mutational accidents on some land-dwelling
mammals, no matter how long you let the process take. A whale's tail is too
well designed to be made that way. In fact, it shows all the evidence of the
intelligent engineering which we associate with deliberate creation.
HAVE you ever
noticed that snakes move rather differently from other reptiles? Those who
claim snakes are simply the legless descendants of other reptiles; really don't
appreciate just how unique snakes are. No matter how carefully you removed the
legs from a lizard, it would never move like a snake. Snakes move the way they
do, because they have a distinctive backbone. To make a lizard or alligator
into a snake, you would need to add special backbones, (vertebrae) in special
places. Without these additional bones, snake movement just isn't possible.
Then there's that mouth. You would need to add an extra row of teeth to start
with, and then specially reshape them. At the same time you must change and
redesign the jaw with a new suspension unit, to give it the special unlockable
snake-wide swallow ability.
The skull would
then need re-enforcing to give more protection to the brain, and then you would
have to change the shape of the throat so that it could breathe as well as
swallow. All this before we even consider how to add special ducts and hollows
for the snake's venom or saliva, change the lungs, rebuild the eyes, and so it
goes on.
Well, how would
you make a snake? One way you wouldn't, is by slow small changes (or mutations)
to a legged reptile. No observed mutation can do anything like produce the
special equipment in a snake, even if you started with a 'soundly functional
lizard'. Snakes have not evolved either slowly or rapidly from any other
creatures we call reptiles. Not only is there no trace of transitional forms in
the fossil record, but no one has ever seen a mutated lizard or snake which
would give a clue as to how it could have evolved to become so legless, and yet
so perfectly adapted to being a snake. In fact, snakes look so deliberately
designed that scientists who say otherwise, haven't really got a leg to stand
on!
David
Attenborough’s acclaimed television series, The Life of Birds, provided
many examples of remarkable features and behaviors in birds. These provide
excellent reasons to doubt the evolutionary philosophy permeating the whole
series. Let’s look at just two.
Many species of the plover (sub-family
Charadrinnae) exhibit a most remarkable behavior. Their nests, lined with grass
and leaves, are usually made in a depression on the ground or simply in long
grass. When sitting on her eggs, the female is almost invisible until one draws
very close. If an intruder such as a hawk or fox is in the area, the bird will
remain dead still until the last minute.
If it seems
likely the intruder will discover the nest, the bird will suddenly rear up and
run in a seemingly disorganized pattern, thus distracting the attention of the
invader away from the nest, the eggs, or the chicks. As it runs, the plover
begins to apparently stumble and struggle as if it has a broken leg or a broken
wing, giving the impression it is disabled and defenseless.
But this
performance is anything but random. As she stumbles around, the mother bird
steadily and imperceptibly works her way ever further from the nest, drawing
the intruder after her with the lure of an easy meal. Within a minute or two
the plover is many meters away from her nest. If attacked, she will magically
‘recover’ and fly off to a distance, watching the invader closely. When the
intruder has departed, the mother bird returns to the nest.
Storks (family Ciconiidae) make their
nests of sticks, reeds and grass, in tall trees. When the chicks hatch, their
thin, featherless skin is extremely vulnerable to the direct rays of the sun.
The parent bird has two responses to the high temperature problem—if water is
nearby, the stork fills its large beak, returns to the nest, and douses the
tiny chicks with cooling water. If this is not sufficient, the parent then
performs a most remarkable feat—it stands over the young and spreads its large
wings over the entire nest, thus shading the chicks from the sun’s rays! Often
it will do this for hours at a time.
It is, of
course, not plausible that birds, with their tiny brains, reason these sorts of
behaviors out for themselves. Such behaviors are automatic and triggered by the
appropriate circumstances. How and when did plovers and storks acquire these
remarkable abilities?
There are only
two real possibilities—one is that the programming for this behavior was in the
genetic code right from the beginning, from the first of each of the respective
kinds.
The other is
time plus chance: natural selection, ‘choosing’ from the alternatives thrown up
by random inherited copying mistakes, has, in a blind unthinking way,
programmed this behavior over millions of years.
Evolutionary
‘just so’ stories are notoriously difficult to put to any sort of test. One
would have to believe in an incredibly fortuitous series of mutations having to
occur in the right sequence and at the right time.
The obvious
alternative seems much more logical and plausible: just as a computer requires
a designer and builder, so this remarkable programmed behavior required the
existence of intelligence above and beyond itself. The Bible points to this
intelligence—the Creator God.
Dr Denton agrees
that natural (as well as artificial) selection is capable of generating some
change in living things. But he says it is ‘completely incapable of accounting
for the broad picture, the complex adaptations required by the tree of life’.
The two most
serious objections he has are as follows:
First, the
nature of mutation (accidental changes in the genetic material of living
things). He says that the ‘essential bedrock of Darwinism’ is the belief that
‘all the organisms which have existed throughout history were generated by the
accumulation of entirely undirected mutations’. In his professional opinion,
‘that is an entirely unsubstantiated belief for which there is not the slightest
evidence whatsoever’.
The second
problem he sees is that there is ‘a huge number of highly complex systems in
nature which cannot be plausibly accounted for in terms of a gradual build-up
of small random mutations’.
Indeed, he says,
‘in many cases there does not exist in the biological literature even an
attempt to explain how these things have come about’. A classic example, he
says, is the lung of the bird, which is ‘unique in being a circulatory lung
rather than a bellows lung [see box]. I think it doesn’t
require a great deal of profound knowledge of biology to see that for an organ
which is so central to the physiology of any higher organism, its drastic
modification in that way by a series of small events is almost inconceivable.
This is something we can’t throw under the carpet again because, basically, as
Darwin said, if any organ can be shown to be incapable of being achieved
gradually in little steps, his theory would be totally overthrown.
‘The fact is
that, in common-sense terms, if you have no axe to grind, there are a vast
number of such cases in nature.’ Michael Denton, a recognized academic in his
field, says that the claim that Darwinian gradualism ‘can generate the sorts of
complex systems we see throughout the biosphere is not only unsubstantiated,
but in many cases it is actually beyond the realm of common sense that such
things would ever happen’.
As
a bird breathes, air moves into its rear air sacs (1). These then expel the air
into the lung (2) and the air flows through the lung into the
front air sacs (3). The air is expelled by the front air sacs as the bird breathes
out. The lung does not expand and contract as does a reptile’s or mammal’s. The
blood which picks up oxygen from the lung flows in the opposite direction to
the air so that blood with the lowest oxygen (blue in the diagram always means
lower oxygen, red means high oxygen) is exposed to air with the lowest oxygen.
The blood with the highest oxygen is exposed to air with an even higher oxygen
concentration. This ensures that, in every region of the circulation, the
concentration of oxygen in the air is more than that of the blood with which it
is in contact. This maximizes the efficiency of oxygen transfer from the air to
the blood. This is known as counter-current exchange. Such very
efficient lungs help birds to handle the energy demands of flight, especially
at high altitudes.1
The reptile
lung, like ours, has an in-out bellows-like arrangement and does not have the
counter-current circulation system. In a mammalian lung (right), the air goes
into sacs called alveoli (singular alveolus). Reptiles and birds possess
septate lungs. A reptile lung is rather like a giant single alveolus,
with ingrowths called septae that divide the lung into spatial units called faviculae
or faveoli. The septae are rich in blood vessels, so oxygen exchange
occurs there.
For a reptile lung to change into a bird
lung by small steps, while remaining functional throughout and providing a
greater advantage at each step, defies imagination, according to Dr Michael Denton,
an open-minded evolutionist. For example, a transitional series from the
reptile to the bird lung design would need to start from a poor creature with a
diaphragmatic hernia (hole in the diaphragm), and natural selection would work against
this. John Ruben, an evolutionary respiratory physiology expert at Oregon State
University in Corvallis, argues:
‘Recently,
conventional wisdom has held that birds are direct descendants of theropod
dinosaurs. 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 air sac system from a
diaphragmatic-ventilating ancestor would have necessitated selection for a
diaphragmatic hernia [i.e. hole] in taxa transitional between theropods and
birds. Such a debilitating condition would have immediately compromised the
entire pulmonary ventilatory apparatus and seems unlikely to have been of any
selective advantage.’
Many of our
textbooks suggest that it is man's superior intelligence which has enabled our
species to modify the environment by technological innovations and so give us
some control of our evolution. Increasing technological advance is seen as our
salvation in the struggle to survive.
However, these
texts do not suggest that our technology was achieved by accident. It is
accepted as the result of applied intelligence building on the achievement of
earlier generations. Animal behavior is the result of inbuilt responses to
external stimuli, allied with a limited ability to learn from experience. While
some animals make limited use of tools, none approaches man's ability to design
and innovate. Yet when we look at the way in which animals are suited to their
environment, we find that many animals have inbuilt devices which far surpass
the technological achievements of which man is so proud.
Take flight, for
instance. Thoresen (1971) claims that if a small aeroplane were as efficient as
the plover, it would fly 56 km on one liter of gasoline. Birds show excellent
aerodynamic design.
Their flight apparatus
includes:
No one of these features
enables flight. It is only when they are put together that birds fly. Each
feature could not evolve separately to its current perfection and then unite
harmoniously with the other.
Flying patterns in the
animal kingdom include power flying, gliding, soaring and flight like the
helicopter of humming birds and dragonflies. Each has special variations for
its specific mode of flight.
It is of interest to
note that our planes, helicopters and gliders, designed with purpose, cannot
match the design standards observed in animals following innate behavior
patterns.
It’s quite a
sight to see geckos, small tropical lizards, running up and down walls and
across ceilings, without any trouble. But what makes their feet stick? Several
plausible ideas have been disproved:
·
Suction? Suction caps work because air pressure
on one side is no longer counterbalanced if there is a vacuum on the other.
Because normal air pressure is 100 kPa (kilopascals), or 14 pounds per square inch,
suction can be very effective. But geckos’ feet can stick in a vacuum where
there is no air pressure, so suction cannot be the reason.
·
Electrostatic
attraction? This is the
attraction between electrically charged objects, for example a plastic comb rubbed
with cloth can pick up small pieces of paper. But when researchers zapped the
surrounding air with X-rays to form charged molecules (ions), which would cause
any charge to leak away, the feet still stuck.
·
Ordinary
glue? There are no skin
glands to produce any.
·
Friction? Keratin, the protein in skin, is too
slippery.
·
Interlocking
between rough surfaces?
Geckos can even stick to polished glass.
The best
explanation seems to be that the geckos’ feet can exploit the weak short-range
bonds between molecules.1 That is, they stick via van der
Waals forces.2 But for such weak forces to work,
there must be an enormous intimate contact area between foot and surface, so
that enough individual weak forces can add up to a very strong force.
Under an
electron microscope, researchers have found that the feet have very fine hairs
(setae), about 1/10th of
a millimeter long and packed 5,000 per square mm (three million per square
inch). In turn, the end of each seta has about 400–1,000 branches ending in a
spatula-like structure about 0.2–0.5 µm (microns—less than 1/50,000th inch) long. These spatulae can
provide the necessary contact area.
With special
instruments,3 a team of biologists and engineers
from several American universities analyzed a seta from the foot of a Tokay
gecko (gecko). The foot pad has an area of about 100 mm2 (0.16 sq. inch) and can produce 10
newtons of adhesive force (enough to support two pounds). But they showed that
an individual seta had an attractive force 10 times stronger than expected. In
fact, one seta is strong enough to support an ant’s weight, while a million
could support a small child. So the gecko has plenty of attractive force to
spare. This means it can handle the rough, irregular surfaces of its natural
habitat.
Actually, the
attractive force is far greater when the seta is gently pressed into the
surface and then pulled along. The force also changes with the angle at which
the hair is attached to the surface, so that the seta can detach at about 30°.
These elaborate properties are exploited by the gecko’s ‘unusually complex
behaviour’1 of uncurling its toes when
attaching, and unpeeling while detaching. This all means that the gecko can not
only stick properly with each step, but also avoid getting stuck, all without
using much energy.
Another amazing
feature is that the gecko’s feet are self-cleaning—unlike sticky tape, to which
dirt easily sticks, rendering it useless. The researchers are still trying to
find out how geckos manage that.
One evolutionist
said: ‘It’s great to look at how evolution has solved mechanical problems’.4 But he never said how
evolution, via chance mutations and natural selection, could have produced the
complex foot structure as well as the movement pattern needed to use the
structure properly. For example, there was no explanation of how half-formed
setae and spatulae and an imperfect movement would benefit the animal and thus
be selected for. This seems more like blind faith for people who have ruled out
a Designer by decree.
But is this
legitimate? The researchers commented that designing such a structure is
‘beyond the limits of human technology’,1 especially finding a material that
can be split so finely 1,000 times. If the structure is ‘beyond the limits of
human technology’, then it’s reasonable to believe that it was designed by One
whose intelligence is beyond our own.
They also
pointed out that the ‘natural technology of gecko foot hairs can provide
biological inspiration for future design of a remarkably effective adhesive’.1 In fact, giving robots sticky feet
and getting them to walk the way geckos do (with the uncurling/unpeeling
action) has made ‘champion climbers’ out of two robots.5 Dr Autumn also commented: ‘Geckos
can do things that we just can’t do with current robotics and adhesive
technology.’6
So not only can
we not design anything as complex as the gecko’s foot, human designers are
learning new things from it. This speaks of a Master Designer of the foot, who
programmed the complex ‘recipe’ for the foot, as well as the movement patterns,
into the gecko’s DNA.
It has often
been said that, according to the laws of aerodynamics, insects shouldn’t be
able to fly. But of course they do — brilliantly. Actually, that only
highlighted our ignorance of aerodynamics. Research over the past few years is
revealing how insects do manage to fly in ways which put the achievements and
maneuverability of our most advanced aircraft to shame.
Conventional
analysis showed that insects were generating only about one-half to one-third
of the lift needed to carry their weight. However, ingenious experiments have
now shown unexpected patterns of vortex flow along the edges of insect wings.
These generate
the extra lift needed because the vortex (a spiraling tube-like pattern of
airflow like a mini-tornado) stays ‘stuck’ to the leading edge of the wing for
long enough.1 At this point, no one knows how or
why this particular vortex phenomenon occurs, but researchers have been able to
see it in a robot model of a moth’s wing inside a wind tunnel.
One reason why
previous models failed to detect how insects could fly is that they used fixed
wings. However, insect wings have a very complex motion, rotating and changing
the camber. It required sophisticated programming to make the ‘robot insect’
flap properly. This demonstrates how sophisticated the (created) design of
actual insect flight must be.
How do ants and bees
walk upside down, an essential skill for walking on plants? Not only must their
feet be able to stick, but also become unstuck at the right time so they can
move quickly.
A University of
Massachusetts team has now shown the amazing way they do this, using high-speed
photography on honeybees and weaver ants walking on glass, and studying the
foot structure under a microscope. The foot has a moist pad (arolium), which
can stick to a surface like wet paper to a window. This is between two claws,
shaped like a bull’s horns.
If the surface
is rough, the claws can catch onto a surface, and the arolium is retracted
because it’s not needed, and is protected from abrasion. But on a smooth
surface where the claws can’t catch onto anything, they retract via the claw
flexor tendon, which also causes the arolium to rotate and extend into
position. This tendon also connects to a plate that squeezes a reservoir of
‘blood’ (hemolymph), forcing the liquid into the arolium to inflate it, so it
presses on the surface.
When the foot
needs to become unstuck, the claw flexor tendon is released, and the arolium
and many of the mechanical parts are so elastic that they quickly spring back
into place. The same basic mechanism applies to both bees and ants, but they
have some differently shaped parts because of their different requirements.
This is a very
complex mechanical and hydraulic design, but controlled very simply, without
any brain input. This enables high reliability and very fast reaction times.
Not surprisingly, this has intrigued designers of miniature robots for medical
purposes.
From the thick
stomach lining of the panda and the partially webbed paws of the polar bear, to
the insect-sucking muzzle of the sloth bear, bears provide a fascinating
example of the variety of specialized characteristics existing within one
family.
The bear family
(Ursidae) consists of eight species, four of which are contained in the Ursus
group: the brown bear, American black bear, Asiatic black bear and polar bear.
Even within this group (known as a genus) the variation is wide.
The brown and
American black bears are mainly vegetarians with appropriate dental features
for crushing plant material. However, the first has claws suited to digging
while the other has claws more suitable for climbing. The Asiatic black bear,
which also has claws for climbing, is an opportunistic omnivorous feeder
(eating meat and plants as available).1
The polar bear,
however, has some amazing features which allow it to function perfectly in its
cold, wet environment. Much heavier than the above bears, it has two distinct
hair types, one long and one short, which effectively is like having two coats.
By increasing buoyancy, this helps it to swim, as does its long neck and the
partial webbing between its toes. Its fur-covered foot pads provide better
traction on the ice. Almost exclusively a meat eater (with teeth to suit such a
diet), the polar bear also has a large stomach capacity for sporadic
(opportunistic) feeding.
The sun bears
and sloth bears (also included in the Ursus group by many scientists)
also have as many differences as similarities. The sun bear is omnivorous, with
sharp, sickle-like claws suited for tree climbing, while the sloth bear
(possessing claws for both digging and tree climbing) has an unusual head and
dental structure perfect for eating its main food source, termites. The sloth
bear’s long muzzle has protrusible lips and nostrils which it can close — these
two features allow it to create a vacuum tube to suck up the termites.
The giant panda,
like the polar bear, has very specialized features necessary for survival,
including powerful jaws and special molars for crushing plants, and an
oesophagus (gullet) with a tough, horny lining to protect the bear from
splinters when it eats bamboo, its primary source of food. The panda’s stomach
also has a thick, muscular lining to protect it from bamboo fragments.
While both
evolutionists and creationists consider these specialized characteristics to be
adaptations to the environment through natural selection, the two camps are
poles apart as to how most of this variation came about in the first place.
Evolutionists
believe that the genetic (hereditary) information (which supplies the ‘recipe’
to construct such specialized features in the developing embryo) all arose by
an accumulation of copying errors (mutations). Any ‘good’ errors which helped
the creature to survive were passed on. In this way, they believe that these design
features are all the result of these copying mistakes, accumulated by selection
over millions of years.
Creationists,
however, while accepting that all of today’s bears probably descended from a
single bear kind,2 do not believe that the information
in the ‘recipes’ for all these design features arose by chance. No-one has ever
observed any biological process adding information!
A better explanation
is that virtually all the necessary information was already there in the
genetic makeup of the first bears, a population created by God with vast
genetic potential for variation.
This doesn’t
mean that all of the features of today’s bears would have been on obvious
display back then. A simple example would be the way in which mongrel dogs
obviously had the potential to develop all the different breeds we see today.
Thus, there was no actual poodle to be seen among mongrel dogs hundreds of years
ago, but by looking closely at many of them, one would have seen at least some
of the individual features found in today’s poodles popping up here and there.
Imagine you are
a honeybee. You leave your hive one fine spring morning and scout around until
you notice a field full of new flowers in bloom. The food back in your hive,
which the 15,000 bees in your colony have fed on through the winter, has been
getting low. But now, in this field, you have found a new food supply. So you
fill your special honey stomach with nectar and fly the 250 meters back to your
hive.
The other bees
do not yet know where to find the blooms you have discovered. Your brain is
only the size of a pinhead, but it is obvious that if you are to fully utilize
this new food source you will need help. Before summer arrives, your colony
could number more than 80,000 bees. But the little bit of pollen and nectar you
would collect in each trip could see your colony starve before each member was
fed. So how do you tell the other bees in your hive where to find the blossoms
you have discovered?
In the early
1900s, Austrian naturalist Karl von Frisch puzzled over this curious problem.
Fascinated with the ways honeybees worked together, von Frisch began a deep
study of them. He found that one of the most remarkable characteristics of bees
is the way they communicate. In fact, bees have one of the most extraordinary
means of communication in the insect world. Von Frisch discovered that bees
express themselves not only by feeling and tasting, but also by dancing.
To identify the
location of a food source too distant from the hive to be smelled or seen by
the other bees, the scout does a dance on the honeycomb inside the hive. Other
bees gather around and closely follow the dancer. They imitate her movements
(all dancing worker bees are female), and note the fragrance on her of the
flowers from which the dancer gathered the nectar.
If the new food
source is nearby, say within about 50 meters of the hive, the bee does a
circular dance on the surface of the honeycomb. She moves around two or three
centimeters (an inch or so), then circles in the opposite direction. This tells
the other bees the food is close by. The scent they detect on her alerts them
to what the new food smells like. So the other bees leave the hive and fly
around in ever-widening circles until they find the new supply of flowers.
Dance
for distance
If the new
source of nectar or pollen is distant, the scout makes an ingenious alteration
to her dance. She dances the shape of a ‘figure eight’, with intermittent
movements across the middle of the figure. The distance at which the changeover
takes place, from round dance to figure eight, varies among different types of
bees. This does not cause them confusion, for the distance is constant within
each hive.
Every movement
by the scout has meaning for the other bees. They can tell the distance
of the food source by the number of times the dancer circles during a given
interval, and also by her wiggling abdomen. The greater the distance, the more
slowly she wiggles. The direction of the food is revealed by the
direction and angle the dancing bee cuts across the circle. If she wiggles
across the circle straight up, the watching bees know they will find the food
by flying towards the sun. If she cuts the circle straight down, they
know they have to fly away from the sun.
If the dancing
bee cuts across the circle at an angle, the other bees know they must fly to
the right or left of the sun at the same angle the dancer moved to the
right or left of an imagined vertical line.
This dazzling
display of the honeybee dancers is truly a striking feature of the insect
world. When we consider the complicated steps of the dance, and the detailed
information conveyed and understood through it by all the world’s honeybees
(von Frisch took 20 years to decipher it), we are entitled to strongly doubt
that this process could ever evolve.
Could
the dance evolve?
Let’s try to
imagine the system evolving. A bee discovers a field in bloom. She returns to
her hive and no one else knows where she filled her honey stomach. She can’t
tell them herself, so the hive has to wait until individual bees haphazardly
chance upon the same field, or she has to keep going back and forward hoping
someone will follow her. Even worse, she may not remember how to get back to
the field herself!
Now let’s
suppose that one day an enterprising bee manages to invent the dance. How would
she communicate to the others what it meant? How could she ever explain the
geometry involved—that the angle she walks across the diameter of the circle is
equal to the angle between the sun and the food source? What if the sun goes
down before the other bees understand? How does she explain she has invented
one dance for a food supply nearby, and another for a supply a long distance
away?
How does she
tell them that if she wiggles very slowly it means the field is very distant,
and if she wiggles very fast it means the field is not far? How will they know
that if the dancer walks up the honeycomb they should fly towards the
sun, but if she walks down they must fly in the opposite direction?
Even more
important, if this process slowly evolved over a long time, how would all the
bee ancestors have survived while this system of communication was evolving? If
they survived without this complicated method, why invent a new system
that would be almost impossible to explain?
Among the
wonders of God’s creation, the honeybee provides some startling evidences
against evolution, and for design and purpose by the Creator. The precisely
coordinated language used for the bee’s survival has too many necessary and
independent parts for such a system to have evolved. We are forced by logic and
common sense to conclude that the whole process was implanted in bees at the
time of their creation. Like the bees, it did not and could not evolve.
The dance of the
figure eight is also used when bees are selecting a new homesite. Under certain
conditions, such as overcrowding, the queen may leave with part of the colony
to search for a new home. She leaves behind one or more queen cells from which
a new queen will hatch. The old queen and her swarm first congregate somewhere,
such as on a branch of a tree. Worker bees are then sent to scout around for a
suitable new homesite. Any scout who finds a potential site returns to the
others and tells them where her favored site is by doing the ‘figure eight’
dance on the surface of the cluster of bees.
Other bees inspect
each site and return to the colony to tell the others what they ‘think’ of it.
The vigor of their dancing reflects their reactions to the suitability of the
site. Finally, after perhaps several days of house-hunting, one of the sites
gains overwhelming favor and the swarm moves off to start a new hive there.
One researcher
watched this dance contest for four days, noting directions and distances of
potential sites. He worked out the site which was rapidly gaining favor, then
hurried off to find it. He arrived at the new dwelling-place before even the
bees did!
Such complicated
communication seems impossible to explain if you believe bees and their
language have evolved.
The peacock tail
contains spectacular beauty because of the large feathers, bright, iridescent
colors and intricate patterns. The colors in the tail feathers are produced by
an optical effect called thin-film interference. The eye pattern has a high
degree of brightness and precision because the color-producing mechanisms contain
an extremely high level of optimum design. According to the theory of sexual
selection, the peacock tail has gradually evolved because the peahen selects
beautiful males for mating. However, there is no satisfactory explanation of
how the sexual selection cycle can start or why the peahen should prefer
beautiful features. In addition, there is irreducible complexity in both the
physical structure of the feather and in the beautiful patterns.
Most birds have
two types of tail feather: flight feathers and tail-coverts. The flight
feathers provide stability during flight, while the tail-coverts ‘cover’ and
protect the tail region. In the vast majority of birds, the tail-coverts are
small feathers, just a few centimeters long. However, some birds like the peacock
have very large tail-coverts for decorative purposes. These decorative feathers
are also referred to as ornamental feathers, or display feathers.1 It should be noted that a peacock is
a male peafowl and a peahen is a female peafowl. The peahen does not have any
decorative feathers.
When a peacock
displays his tail feathers during courtship, a magnificent ‘fan formation’ of
feathers forms a beautiful backdrop to the body of the peacock as shown in
Figure 1 (below). An adult peacock has an average of 200 tail feathers and
these are shed and re-grown annually. Of the 200 or so feathers, about 170 are
‘eye’ feathers and 30 are ‘T’ feathers. The ‘eyes’ are sometimes referred to as
ocellations.
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Figure 1. Peacock with tail feathers displayed. |
When the peacock
feathers are displayed there are several beautiful features that can be seen:
·
Fan
formation of feathers
·
Uniform
distribution of ‘eyes’
·
Intricate
‘eye’ feathers
·
Intricate
‘T’ feathers
One reason for the beauty
of the displayed feathers is that they form a semi-circular fan over an angle
of more than 180 degrees. The fan formation is very even because the axis of
every feather can be projected back to an approximately common geometrical
center. The radial alignment of feathers requires the root of each feather to
be pointed with a remarkable degree of accuracy. Another remarkable feature of
the displayed feathers is that they are ‘deployed’ into position by muscles in
the peacock’s tail. Not only can the peacock deploy the feathers, but he can
also make them vibrate and produce a characteristic hum.
Another beautiful
feature of the displayed feathers is the uniform spacing of the eyes. Even
though the display contains around 170 eye feathers, they are all visible and
all spaced apart with a remarkable degree of uniformity. All the eyes are
visible because the feathers are layered with the short feathers at the front
and the longer feathers at the back. The eyes have an even spacing because each
feather has the right length.
Each ‘eye’ feather
and ‘T’ feather is an object of outstanding beauty in itself. The eyes contain
beautiful patterns, and the ‘T’-shaped feathers form a beautiful border to the
fan.
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Figure 2. Structure of the eye feather. |
Figure 2 (right) shows
a sketch of the top section of the eye feather. There are several beautiful
features to the feather:
·
Bright
colors
·
Intricate
eye pattern
·
Loose barbs
below the eye pattern
·
Absence of
stem in the top half of eye pattern
·
Narrow stem
in the bottom half of eye pattern
·
Brown
coating of the stem near the eye pattern
The bright
colors and intricate shapes of the eye pattern are the most striking aesthetic
features. The loose barbs on the lower part of the feather are beautiful
because they make a contrast with the neatness and precision of the barbs in
the eye pattern.
The last three
features in the list above are usually only noticed by very careful observers.
However they represent important ‘finishing touches’ which make an important
contribution to the beauty of the feather. The absence of a stem in the top
half of the eye is an important detail because it prevents the pattern from
being divided into two sections. The stem is not needed because the barbs fan
out around the top of the feather. The narrowness of the stem in the bottom
half of the eye pattern is important because this makes the stem fairly
obscure. The stem can be narrow because it has a deep section in the area of
the eye pattern. The brown coating of the stem in the area of the eye pattern is
very important because the stem is a natural white color and this would be too
conspicuous for the eye pattern. It is interesting to note that the stem is
white everywhere except local to the eye pattern. This strongly indicates that
the brown coating near the eye pattern is a deliberate feature.
A large eye
feather has been examined at Bristol University to determine the number and
size of each part of the feather. The number and size of barbules was estimated
by examining sample sections of barbs with a microscope. The data for the
feather are summarized as follows:
The colors in
the peacock tail are particularly beautiful because they are bright and
iridescent. An iridescent color is a color that changes with the angle of view.
The colors are not produced by pigments but by an optical effect called
thin-film interference that takes place in the barbules.4 In technical terms, the peacock has
‘structural colors’.
In the eye
pattern, the barbules appear bronze, blue, dark purple and green. Away from the
eye region, the barbules are uniformly green. The colors in the eye feather can
only be seen on the front surface of the feather because this is where the
barbules are positioned. The back of the feather is uniformly brown because the
barbs contain a brown pigment. To understand how thin-film interference is
produced in the peacock tail, it is first necessary to understand the detailed
structure of the feather.
The basic
structure of the peacock tail feather in the eye region is shown in Figure 3(a)
(right). For comparison, the structure of a typical flight feather is shown in
Figure 3(b) (right). Like the flight feather, the peacock tail feather has a
central stem with an array of barbs on each side. Also, individual barbs have
an array of barbules on each side of the barb. Even though there is a basic
similarity with a flight feather, the peacock tail feather has an unusual
barbule structure. The barbules are like long flat ribbons that overlap to form
a flat surface on top of the barbs. (Under a microscope the barbules are
actually slightly curved and segmented and the surface has a bubbly appearance).
In contrast, a flight feather has narrow barbules which do not cover the barbs.
Other types of birds such as hummingbirds, pigeons and kingfishers have some
patches of flat iridescent barbules, but the peacock has the largest iridescent
barbules of any known bird.5
The colors of
the barbules dominate the front face of the tail feather because they completely
cover the barbs. The barbules are not very visible from the back of the feather
because the barbs are quite close together.
Thin-film
interference can be produced in one or more layers of a very thin and transparent
material. Usually the thin film is placed on a dark surface. The thickness of
the transparent material must be close to the wavelengths of visible light.
Visible colors have wavelengths between 0.4 and 0.8 µ and thin films typically
have a thickness of between 0.3 and 1.5 µ. Another requirement for thin-film
interference is that the thin film must have a refractive index that differs
from air so that the light is retarded when it passes through the thin film.
Thin-film interference commonly occurs in oil slicks on a wet road. The oil
will often form a thin layer on the wet surface of the road or on the surface
of a puddle, the thin-film producing blue and green colors.
In the case of
the peacock, thin film interference takes place in three layers of keratin
which cover the barbules as shown in Figure 4. Each barbule is about 60 µ wide
and 5 µ thick.6 The barbules have a foam core that
is 2 µ thick and this is covered with three layers of keratin on each side, as
shown in Figure 4 (below). The keratin layers are very thin, being about
0.4–0.5 µ thick.7
The principle of
thin-film interference in a single layer of keratin is shown in Figure 4. White
light is reflected off the front and back surfaces of the thin film. The light
which passes through the keratin is retarded and therefore when it emerges from
the keratin, some of the color components of white light are out of phase with
the light-waves that were reflected from the front surface. When two wave
trains of the same color are out of phase, destructive interference removes the
color. In the case of white light, the result of the interference is a
reflected color due to the remaining color components of white light. In
practice, interference occurs simultaneously in all three thin films.
The only pigment
in the peacock tail is melanin, which gives the barbs a uniform brown color.
This provides a dark background color for the thin-film interference in the
keratin layers. The different colors in the eye pattern result from minute
changes in the depth of thickness of the keratin layers.8 In order to produce a particular
color, the keratin thickness must be accurate to within about 0.05 µm (one
twenty thousandth of one millimeter!).
The barbules in
the peacock feather contain a high degree of optimum design. The thickness of
the keratin layers is optimal for producing the brightest thin-film colors. The
dark brown background coloring is optimal because it prevents light shining
through the back of the feather. The three layers add to the brilliance of the
colors in the feather by adding multiple components of light. The barbules are
also slightly curved in the longitudinal direction.9 This curvature causes a mingling of
slightly different colors, which produces a softening of the colors seen in the
keratin layers.9
The particular
beauty of the eye pattern comes from the rounded shapes that have a high degree
of resolution as shown in Figure 5 (below). The ‘pupil’ of the eye is formed by
a dark purple cardioid and the ‘iris’ is formed by a blue ellipsoid. These
shapes are located within a pointed bronze ellipsoid that is surrounded by one
or two green fringes.
A very important
feature of the eye pattern is that it is a digital pattern which is formed
by the combined effect of many thousands of individual barbules. Some patterns
in nature are formed by natural growth mechanisms, as with the spiral shape of
the nautilus shell. However, the eye pattern in the peacock tail requires the
precise coordination of independent barbs and this cannot be achieved by a
simple growth mechanism. Barbules on adjacent barbs coordinate perfectly with
each other to produce the eye pattern.
The spacing of
colors on each barb must be specified by instructions in the genetic code. To
specify the pattern, there must be timing or positional instructions in the DNA
which causes the right thickness of keratin to be grown on the right barbule
and on the right barb. To help appreciate the precise nature of the information
in the genetic code, it is helpful to consider the mathematical complexity
involved in calculating the required spacing of colors on each barb.
Figure 6 (right)
shows the color spacing on a single barb. Along the first part of barb ‘n’,
the thickness of the keratin films on the barbules gives a bronze color. Then
an abrupt and minute change in thickness of the keratin films produces a blue
color. Another abrupt and minute change in thickness of the keratin films so
produces a bronze color. The abrupt nature of the changes in thickness is
important because if the changes were gradual then there would be a gradual
change in colour.10 The abrupt changes in thickness of
keratin along a barb are an amazing feature because it involves sudden and
precise changes in the dimensions of the barbule. Even more amazingly, along
the length of the barb the thickness of the keratin does not continually get
thicker and thicker (or thinner and thinner) but it involves both increases and
decreases in thickness.
A similar
procedure can be used for the intersection points on the cardioid shape and the
outer green fringes. For each barb there are on average about four points at
which color changes and so there are on average four positions to calculate.
Since there are around 50 barbs on each side of the pattern and since every one
of these barbs has a unique spacing of color, it is necessary to calculate 200
intersection points in order to construct the whole eye pattern.
‘T’ border
feathers
The long ‘T’
border feathers provide a beautiful border to the tail feathers because they
form an inverse shape to the peacock eye as shown in Figure 7 (below). An
inverse shape is beautiful because the inside profile of the T feather follows
the outline of the eye pattern. The T feathers often form an ‘ogee’ curve on
each side of the feather as shown in Figure 7. An ogee curve is beautiful
because it is both concave and convex. For this reason, ogee curves are used in
architecture in structures such as arches. The formation of an ogee curve from
individual barbs is yet another remarkable feature of the peacock tail. Each
barb at the end of the T feather has a unique length and curvature and all the
barbs coordinate exactly with each other to form the curved T.
Every detail in
the peacock tail must be defined by genes in the genetic code of the peafowl.
Since the tail feathers have very complicated structures and color-producing
mechanisms, there must be a large amount of design information in the genetic
code.
It is difficult
to determine how many genes would be required to specify the aesthetic features
of a peacock tail feather because it is not known how the tail feather grows.
However, a conservative estimate can be made by assuming that each separate
aesthetic feature is specified by one gene. By assuming that each color and
each shape within the eye pattern represents a separate feature, and taking
into account the other features discussed in this paper, the total number of
aesthetic features in a single feather comes to about 20. Therefore an
estimated 20 genes are required for the peacock tail. This may be a very
conservative estimate. In particular, it may be that many genes are required to
produce each shape in the eye pattern since the eye pattern is formed from the
coordinated arrangement of over 100 barbs. In addition, the fanning-out of
barbs in the top of the feather, where there is no stem, is a complex feature
that may well need several controlling genes.
Even if only 20
genes are required to specify the beautiful features of the peacock tail, this
still amounts to a lot of genetic information. A gene typically consists of
1,000 chemical units of information (base pairs). Therefore, 20 genes would
contain many thousands of chemical units of information. According to
evolutionists, all of this information has appeared gradually by genetic
mistakes and by sexual selection.