For Charles
Darwin, natural selection explained the appearance of design without a
designer. There was no longer any need to invoke an intelligent cause for the
complexity of life. Today, Darwinism is generally assumed as being the gold
standard throughout science and the academic world. Yet, despite its wide
acceptance, a growing number of scientists and scholars have begun challenging
key aspects of Darwinian theory. Most notably in 1993, when a group of
scientists in California decided to reassess the origins of life based on the
findings of modern science. This group
became known as the "Behe 7 " and came to one simple conclusion. The
more we know about life and the more we know about biology, the more problems
Darwinism has.
"For
the longest time, I believed that Darwinian evolution explained what we saw in
biology. Not because I saw how it could actually explain it, but because I was
told that it did explain it. In schools I was taught Darwinian biology." -
video quote.
The idea of
irreducible complexity can be illustrated by a familiar, non-biological
machine, a mouse trap. The trap is composed of five basic parts. A catch, to hold the bait; a strong spring; a thin bent rod
called the hammer; a holding bar to secure the hammer in place; and a platform
upon which the entire system is mounted. If any one of these parts is missing
or defective, the mechanism will not work. All components of this irreducible
complex system must be present for the machine to perform its function.
In
evolutionary terms, you have to be able to explain how you can build this
system gradually when there’s no function until you have all those parts in
place. The
irreducible complexity of molecular machines poses a severe challenge to the idea
that natural selection explains the origins of life.
According
to Darwin’s theory, even very complex biological structures (like an eye, an
ear or a heart) can be built gradually over time, in small incremental steps.
Yet, as Darwin made clear, natural selection can only succeed if these random
genetic changes provide some sort of advantage to the evolving organism in its
struggle for survival. So, how could something new, like a bacteria flagellar
motor, develop out of a population of bacteria that doesn't have one? When each
change, according to Darwin’s theory, has to provide some sort of advantage.
Imagine
such a scenario, early in the Earth’s history. An evolving bacterium somehow
develops a tail and perhaps even the pieces necessary to attach it to the cell
wall. But without a complete motor assembly, this innovation would provide no
advantage to the cell. Instead, the tail would lie immobile and useless.
Invisible to natural selection, which by definition can only favor changes that
aid survival.
The logic
of natural selection is very demanding. Unless the flagellum mechanism is
completely assembled, and actually works, natural selection simply cannot
preserve it. It cannot be passed on to the next generation.
“In most cases, natural selection actually
eliminates things...things that have no function, or have a function that harms
the organism. So if you had a bacterium with a tail that didn’t function as a
flagellum, chances are natural selection would eliminate it.”
The only
way you can select for a flagellum is if you have a flagellum that works and
that means you have to have all the pieces of the motor in place to begin with.
So, natural selection can’t get you the
bacterial flagellum. It can only work after the flagellum is there and operating.
Michael
Behe published a book in the mid 90’s titled, “Darwin’s Black Box.” In it, he
argued that natural selection could not explain the origin of the bacterial
flagellum or any other irreducibly complex biological system. Darwin’s Black
Box created immediate controversy. Over seventy-five publications reviewed the
book. Behe’s critics insisted that he had underestimated the power of natural
selection. They argued that the flagellar motor could have been constructed
from parts used to build simpler molecular machines. If the components of the
flagellar motor already existed, they could have been preserved by natural
selection even before the bacterial motor arose. This theory is called,
“co-option.”
This theory
is essentially saying that evolution or natural selection, at some point, was
able to borrow components of one molecular machine and build a new machine with
some of these components.” Scott Minnich has studied the flagellar motor for
nearly 20 years. His research has led him to challenge the co-option argument.
"With
a bacterial flagellum, you're talking about a machine that's got 40 structural
parts. Yes, we find 10 of them are involved in another molecular machine, but
the other 30 are unique, So where are you going to borrow them from?
Eventually
you're going to have to account for the function of every single part that is originally having some other purpose.
I mean, you can only follow that argument so far until you run into the problem
that you're borrowing from nothing. But, even if you concede that you have all
the parts necessary to build one of these machines, that’s only part of the
problem. Maybe even more complex, is the assembly instructions. This is never
addressed by opponents of the irreducible complexity argument." - video
quote
Studies of
the bacterial motor have revealed an ever deeper level of complexity. For its
construction not only requires specific parts, but also a precise sequence of
assembly.
You've got
to make things at the right time. You've got to make the right number of
components. You've got to assemble them in a sequential manner. You've got to
be able to tell if you've assembled it properly so that you don't waste energy
building a structure that are not going to be functional.
Building a
molecular machine has been compared to the construction of a house. Where
workers follow a detailed blueprint or plan for assembly. The foundation of a
house is poured before the walls are erected. Plumbing and electrical fixtures
are installed prior to enclosing the walls of the structure. Windows must be
hung before siding is applied. And shingles are attached only after plywood
sheets are nailed to the rafters. So it is with the construction of a flagellar
motor.
You build
this structure from the inside out. You are counting the number of components
in a ring structure of the stator, and once that's assembled, there's feedback
that says, “okay, no more of that component. “ Now, a rod is added. A ring is
added. Another rod is added. The U-joints added. Once the U-joints are at a
certain size, and certain degree of bend (about a quarter turn), that's shut
off...and then you start adding components for a propeller. These are all made
in a precise sequence, just like you would build a building.
Building
the motor correctly requires a complex system of machines that coordinate the
timing of the assembly instructions. But how could natural selection construct
such a system?
The
co-option argument doesn’t explain this. You see, in order to construct that
flagellar mechanism—or the tens of thousands of other such mechanisms in the
cell—you require other machines to regulate the assembly in those structures.
And those mechanisms, themselves, require machines for their assembly.
If even one
of these pieces is missing or put in the wrong place, your motor isn’t going to
work. So this apparatus to assemble the flagellar motor is, itself, irreducibly
complex. In fact, what we have here, is irreducible complexity all the way
down.
We know a
lot about the bacterial flagellum. We still have a lot to learn, but we know a
lot about it and there's no explanation for how this complex molecular machine
was ever produced by a Darwinian mechanism.
One-hundred
and fifty years ago, scientists did not know about irreducibly complex
molecular machines. Yet, Charles Darwin anticipated the difficulty that systems
such as these could pose to his theory.
“If it
could be demonstrated that any complex organ existed, which could not possibly
have been formed by numerous, successive, slight modifications, my theory would
absolutely break down.”
- Charles
Darwin
There are
really two big questions in biology. How do you get new living forms - with new
structures like wings and eyes - from life that already exists? And, secondly,
how did life on earth originate in the first place?
During the
final years of his life, Darwin did little to develop his idea that a primitive
cell might have emerged from simple chemicals in the primordial waters of the
early Earth. But, later, in the 1920’s and 30’s a Russian scientist named Alexander
Oparin, formulated a detailed theory about how this could have happened. It was
called “chemical evolution.”
Oparin
thought that he could explain the origin of the first life using Darwinian
principles. He envisioned simple chemicals combining and recombining to form
larger molecules. And then these larger molecules organizing themselves (with
the help of chance variations and natural selection) into the first primitive
living cell.
Over the
next three decades many scientists worked to develop and refine these ideas, as
they pondered the questions both Oparin and Darwin had raised. How could life
have evolved from simple chemicals?
One man
thought he knew.
The problem
of biological origins for a very long time I would say, has been a real deep
interest to me just because of the scale of the problem. The importance of it.
Where did we come from? Why are we here? Questions like these, probed from the
perspective of natural science.
During the
1960’s and 70’s Dean Kenyon was one of the leading chemical evolutionary
theorists in the world. Like others in his field, he was trying to explain how
life on earth began through a purely natural process.
In 1969,
Kenyon co-authored an important book on the origin of life.
“Gary
Steinman and myself thought that if we were to pull together all of the lines
of empirical evidence that had accumulated by the mid to late 60’s into one
continuous argument, we were very enthusiastic about the possibilities for
explaining the origin of the main life-building elements.” - Dean Kenyon
Despite his
optimism, Kenyon faced a significant problem. To explain how life began, he
first had to account for the origin of the essential building blocks of every
cell that has existed on Earth. Large, complex molecules called proteins.
Proteins
have a wide range of functions in the cell. Everything from structural
requirements, in terms of scaffolding of the cell... to enzymes where they're
actually processing molecules to harvest energy or to build components of the
cell.
Proteins do
pretty much all of the day to day jobs inside of the cell, such as cleaning up
the cell, making energy and the like, it's all proteins.
Kenyon knew
that proteins would have been as important to the first life as they are to
living cells today. He also recognized the complexity of their construction.
By the
1960’s, scientists had determined that even simple cells are made of thousands
of different types of proteins...and the function of these molecules derives
from their highly complex three dimensional shapes.
The
irregular shapes of some proteins allow them to catalyze, or trigger chemical
reactions, because of the hand in glove fit they have with other molecules in
the cell while other protein molecules form interlocking structural components.
The
individual parts of a bacterial motor, like this ring structure, are each made
of either a single protein molecule or an assembly of proteins fitted together
into a specific shape. These proteins are, in turn, made of smaller chemical
units called amino acids which are linked together in long chains.
There is a
very great degree of intricacy of architecture down in these cell units...in
these protein forming amino acids.
In nature,
twenty different types of amino acids are used to construct protein chains.
Biologists have compared them to the letters of the English alphabet.
Alphabetic
letters can be arranged in a huge number of possible combinations. Where the
sequential arrangement of the letters determines if you have meaningful words
and sentences. If the
letters are arranged correctly, you will get meaningful text. But if they’re
not arranged correctly, then you’ll get gibberish.
The same principle applies for amino
acids and proteins. There are at least thirty-thousand distinct types of
proteins. Each made of a different combination of the same twenty amino acids.
They are arranged, like letters, to form chains often hundreds of units long.
If the amino acids are sequenced correctly, then the chain will fold into a
functioning protein.
Proteins are arranged with their amino acids in
such a way that the amino acids collapse on each other into an architecture
that is pre-programmed by the order of the amino acids. It folds into a certain
structure and that structure can do a certain function.
So all
proteins in the cell have a certain three-dimensional pattern that's based on
the arrangement of amino acids in the chain.
This
arrangement is critical. For, if the amino acids are incorrectly sequenced, a
useless chain forms. And instead of folding into a protein, it will be
destroyed by the cell.
Proteins,
like written languages, have a high degree of specificity. The function of the
whole depends upon the precise arrangement of the individual parts. But what
produces the precise sequencing of amino acids that gives rise to the specific
shapes and functions of proteins? In his book, “Biochemical predestination,”
Kenyon and his co-author, Gary Steinman, proposed an intriguing theory. Life
might have been ‘biochemically predestined by the properties of attraction that
exist between its chemical parts - particularily between amino acids in
proteins.
At the time
Biochemical Predestination came out, I and my co-author were totally convinced
we had the scientific explanation for origins.
Kenyon
proposed that the chemical properties of the amino acids caused them to be
attracted to each other forming the long chains that became the first
proteins—the most important components in the living cell. And, this meant that
life was, effectively, inevitable. Predestined by nothing more than chemistry.
Many
scientists embraced kenyon’s ideas and over the next twenty years, “Biochemical
Predestination” became a best selling text on the theory of chemical evolution.
Yet, five years after the book’s publication, Kenyon quietly began to doubt the
plausibility of his own theory.
It was
during that whole period of time period that my doubts about certain aspects of
the evolutionary camp became apparent when coming into contact with a powerful
counter-argument, given to me by one of my students. And I could not refute
that counter-argument.
Keynyon was
challenged to explain how the first proteins could have been assembled without
the help of genetic instructions. In living cells today, chains of amino acids
are not formed directly by forces of attraction between their parts. The
scenario Kenyon envisioned on the early Earth. Instead, another large molecule
within the cell stores instructions for sequencing the amino acids in proteins.
These molecules are called DNA.
Initially,
Kenyon believed that proteins could have formed directly from amino acids,
without any DNA assembly instructions...and that’s why so many scientists were
excited about his theory.
But, the
more he and others learned about the properties of amino acids and proteins,
the more he began to doubt that proteins could self-assemble without DNA.
In a
written language, information is communicated by a precise arrangement of
letters. In the same way, the instructions necessary to assemble amino acids
into proteins are conveyed by the sequences of chemicals arranged along the
spine of the DNA. This chemical code has been called the “language of life.”
And it is the most densely packed and elaborately detailed assembly of
information in the known universe.
Like other
scientists working on the origin of life, Kenyon realized he had two choices.
Either he had to explain where these genetic assembly instructions came from or
he had to explain how proteins could have arisen—directly from amino acids—without
DNA, in the primordial oceans. And in the end he realized, he could do neither.
It’s an
enormous problem how you could get together, in one tiny submicroscopic volume
of the primitive ocean, all of the hundreds of different molecular components
you would need in order for a self- replicating cycle to be established and so
my doubts about whether amino acids could order themselves into
meaningful biological sequences on their own, without pre-existing genetic
material being present, just reached, for me the intellectual breaking point
near the end of the decade of the 70’s.
As Kenyon
re-evaluated his theory, new biochemical discoveries further weakened his
conviction that amino acids could have organized themselves into proteins.
Further
experimental work showed that amino acids do not have the ability to order
themselves into any biologically meaningful sequences.
Faced with
mounting difficulties in his own theory and a growing body of scientific data
about the importance of DNA. Kenyon was forced to confront the absolute
necessity of genetic information.
** The more I thought about the alternative that was being
presented in the criticism and the enormous problem that all of us in this
field had neglected to address the problem of the origin of genetic
information, itself. Then I really had to reassess my whole position regarding
origins. **
For Dean
Kenyon, a new question became the focus of his search for life’s origin. What
was the source of the biological information in DNA?
If one
could get at the origin of the messages, the encoded messages within the living
machinery then you would really be onto something far more intellectually
satisfying than this chemical evolution theory.
Yet, Kenyon
realized that he faced a narrowing set of options. By the 1970s, most
researchers had rejected the idea that the information necessary to build the
first cell originated by chance alone.
To
understand why, consider the difficulty of generating just two lines of
Shakespeare’s play, “Hamlet,” by dropping scrabble letters on to a table top.
Then consider that the specific genetic instructions required to build the
proteins in even the simplest one-celled organism would fill hundreds of pages
of printed text.
Of course,
serious origin of life biologists didn’t believe that life had arisen by
chance, alone. Instead, they envisioned natural selection acting upon random
variations among chemicals to produce the first life. But there was a problem
with this proposal.
By definition, natural selection could not have functioned
before the existence of the first living cell. For it can only act upon
organisms capable of replicating themselves. Cells equipped with DNA that pass
on their genetic changes to future generations.
Without
DNA, there is no self replication. But without self-replication, there is no
natural selection. So you can’t use natural selection to explain the origin of
DNA without assuming the existence of the very thing you’re trying to explain.
We have not
the slightest chance of a chemical evolutionary origin for even the simplest of
cells...so, the concept of the intelligent design of life was immensely
attractive to me and made a great deal of sense, as it very closely matched the
multiple discoveries of molecular biology.
After
entering the heart of the cell, we see the tightly wound strands of DNA --
storehouses for the instructions necessary to build every protein in an
organism.
In a
process known as, “Transcription,” a molecular machine first unwinds a section
of the DNA helix to expose the genetic instructions needed to assemble a
specific protein molecule. Another machine then copies these instructions to
form a molecule known as “messenger RNA.” When transcription is complete, the
slender RNA strand carries the genetic information through the “Nuclear Pore
Complex,” the gatekeeper for traffic in and out of the cell nucleus.
The
messenger RNA strand is directed to a two-part molecular factory called a
ribosome. After attaching itself securely, the process of translation begins.
Inside the ribosome, a molecular assembly line builds a specifically sequenced
chain of amino acids. These amino acids are transported from another part of
the cell and are then linked into chains; often hundreds of units long. Their
sequential arrangement determines the type of protein manufactured.
When the
chain is finished, it is moved from the ribosome to a barrel shaped machine
that helps fold it into the precise shape critical to its function. After the
chain is folded into a protein, it is then released and escorted by another
molecular machine to the exact location where it is needed.
This is
absolutely mind boggling to perceive at this scale of size; such a finely tuned
apparatus, a device, that bears the marks of intelligent design and
manufacture.
And, we
have the details of an immensely complex molecular
realm of genetic information processing. And it’s exactly this new realm of
molecular genetics where we see the most compelling evidence of design on the
earth.
Our
understanding of genetics, today, revolves around the principle idea that a
specific gene corresponds to a specific protein. Scientists have discovered
that genes are grouped together into what is referred to as a chromosome. Genes
are separated from one another on the chromosome by DNA that serves as a filler,
or a buffer, to protect the information that is actually used for the making of
proteins. The region of DNA that actually codes for the protein (the real
‘gene’) is scientifically referred to as the “Intron.”
These
Intron regions are so complex, they can control the production of molecules in
real time. The first clues of their complexity came in the early twentieth
century when scientists began understanding the metabolic pathways used by
living organisms.
And, yet, curiously, we make inferences to intelligence all
the time. It’s part of our ordinary reasoning...to recognize the effects of
intelligence.
Consider,
for example, heiroglyphic messages carved upon the ruins of egyptian monuments.
No one would attribute the shapes and arrangements of these symbols to natural
causes like sand storms or erosion.
Instead, we
recognize them as the work of ancient scribes; intelligent human agents. Nor,
do we presume that plants could grow into sculpted shapes without some matter
of guidance.
Now if you
travel through the west, you’ll see lots of different shapes on the
mountainsides, most of which mean nothing at all. They’re just rocks strewn in
various patterns. But, what you don’t see are the faces of Lincoln, Jefferson,
Teddy Roosevelt, and George Washington on the mountainsides. The only place you
see that is in South Dakota. And the reason it’s there is because a
sculptor--an eccentric sculptor--decided he wanted to honor these Presidents by
spending the larger part of his life chiseling their faces in the side of the
mountain.
That
pattern is improbable. A random hillside is also improbable. But a random
hillside doesn’t specify anything. We do know though, that there were four men
who were presidents of the United States, who had particular patterns in their
faces...and those patterns on the mountainside in south Dakota match faces
elsewhere.
If I look
at the faces, I immediately recognize that they match the faces of the four
presidents that are known from money or portraits in the National Gallery...or
from paintings in books. And so, I realize that when I look at Mt. Rushmore, we
not only have a highly improbable configuration of rock...but one which matches
an independently given pattern that reliably indicates intelligence.
The heart
of intelligent design lies in the code that is embedded in every living being
on earth. weather you are a plant or an animal life uses the same triplet code
to express the physical features we see in every living organism. we call this
code DNA. DNA has a structure that is ideal for carrying information
A full
compliment of human DNA has three billion individual characters. Analysis of
the DNA molecule’s coding regions show that its chemical characters have a
specific arrangement that allows them to convey detailed instructions. Much
like the letters in a meaningful sentence or like binary digits in a computer
code.
Bill Gates
has said that DNA is like a computer program only much more complex than any
we’ve been able to devise. And if you reflect on that, for even a minute, it’s
a highly suggestive observation. Because we know that Bill Gates does not
employ wind and erosion and random number generators to generate software.
Rather, he employs intelligent engineers. Software engineers. So, everything we
know tells us that information-rich systems arise from intelligent design—
There is,
in fact, nothing in the known universe that stores and processes more
information, more efficiently, than the DNA molecule.
But, what
do we make of the fact that there is information in life? In every living cell
of every living organism? That’s the fundamental mystery. Where does that
information come from?”
For the past 15 years, philosopher and scientist, Stephen
Meyer has worked to answer this question. Meyer has developed an argument to
demonstrate how intelligent design provides the best explanation for the origin
of information necessary to build the first living cell.
It’s part of our knowledge base that intelligent agents can
produce information-rich systems... so the argument is not based on what we
don’t know, but its based on what we do know about the cause and effect
structure of the world.”
We know, at present, there is no materialistic explanation,
no natural cause that produces information. Not natural selection, not self-
organizational processes, not pure chance. But we do know of a cause that is
capable of producing information and that is intelligence. And so when people
infer design from the presence of information in DNA, they’re effectively
making what’s called (in the historical sciences) an inference to the best explanation.”
So when we find an information-rich system in the cell, in
the DNA molecule specifically, we can infer that intelligence played a role in
the origin of that system, even if we weren’t there to observe the system
coming into existence.”
Meyer’s work on the origin of genetic information, is now
part of a comprehensive scientific case for design that grew out of a meeting
of scientists and philosophers on the central coast of California in 1993.
Their objective was to reassess an idea that had dominated biology for more
than a century. In the process, they gave birth to a theory that has become
known as “Intelligent Design.”
To me, the
great promise of design is that it gives us a new tool and explanation that
belongs in the tool chest of science. Intelligent causes are real. They leave
evidence of their existence. And a healthy science is a science that seeks the
truth and lets the evidence speak for itself.
The
argument for intelligent design is based upon observation of the facts. Now
that’s my definition of good science. It’s observation of the facts. And when
you observe the facts, as Michael Behe has done, you observe this incredible
pattern of interrelated complexity...
And the way
we conclude intelligent design for the bacterial flagellum is the same way we
conclude intelligent design for an outboard motor. When we see an outboard
motor, we see the parts interact, and so on, we know that somebody made that.
The reasoning is the same for biological machines, so the idea of design is a
completely scientific one. Certainly, it might have religious implications, but
it does not depend on religious premises.
When I look
at the evidence objectively, without ruling out the possibility of
design...design just leaps up as the most likely explanation. And that’s why I
believe that it’s true.
I think
design is back on the table. We can't explain these systems by natural law and
if we're searching for truth and they are in fact designed if we have to be
design engineers to understand them, then I say, "What's the
problem?" You know you go where the data leads you and the implications,
yeah, they have profound metaphysical implications, but so be it.”
So, It’s a
powerful idea that the universe is rational and comprehensible, underwritten by
a supreme intelligence that meant for this world to be understood, is something
that underwrites the program of science because then you can look at the world
and the world will make sense.
If it’s all
just a chaotic assemblage then there’s no reason to expect any rationality out
there. But, if it in fact, it’s the product of a mind ...then you can go out
and science becomes this enormous, wonderful puzzle solving project in which
you can expect to find rationality and beauty and comprehensibility, right at
the foundation of things.”
One-hundred
and fifty years ago, Charles Darwin transformed science with his theory of
natural selection. Today, that theory faces a formidable challenge. Intelligent
design has sparked both discovery and intense debate over the origin of life on
Earth. And for a growing number of scientists, it represents a paradigm. An
idea with the power to, once again, redefine our understanding of the natural
world.
During the
19th century, scientists believed that there were two foundational
entities—matter and energy. But as we begin the 21st century, there’s a third
fundamental entity that science has had to recognize, and that is information.
And, so as
we encounter the biology of the information age, the suspicion is growing that
what we’re seeing in the DNA molecule is actually an artifact of mind. An
artifact of intelligence. Something that can only be explained by intelligent
design.”
