Life in a test-tube
by Cheri Williams
For decades, Hollywood has been presenting images of ‘Martians’ and
‘space creatures’ through movies such as Independence Day and
Alien. Behind this is the idea of evolution: if life evolved on earth,
then why couldn’t it have evolved on other planets? One famous experiment
is widely touted as proof that life could have evolved from non-living chemicals.
Miller’s experiment
In 1953, the same year that DNA’s double helix structure was discovered, a
young graduate student named Stanley Miller sparked some gases and formed amino
acids. These are the building blocks of proteins, a major component of living cells.
So thousands of newspapers worldwide erroneously reported that he had, in essence,
created life in a test-tube. This experiment became textbook orthodoxy.
However, textbooks tend to present alleged ‘proofs’ of evolution without
critical discussion. Unless students consult outside sources, they often over-value
the connection between organic molecules and life. Bold claims such as ‘organic
molecules could have arisen on a lifeless Earth’ tend to mislead students
into believing that organic molecules are life. However, ‘organic’
does not mean the molecules are alive, but simply refers to any molecule
that contains the element carbon.
Bold claims such as ‘organic molecules could have arisen on a lifeless Earth’
tend to mislead students into believing that organic molecules are life.
Some of the organic compounds of significance to the origin of life are amino acids
and sugars. For life to exist, these and other non-living components must be arranged
in a special way. The difference between living and non-living things is not so
much the substances they contain, but how these substances are organized.
But can non-living chemicals organize themselves into the sorts of precise sequences
that we observe in living systems today? Did Miller’s experiment really show
that matter has this capability? Thinking in purely naturalistic terms, let’s
try to answer that question. How could the first cell have originated in the hypothetical
‘prebiotic soup’? What would have been the first sub-units formed that
later might have given rise to the first cell?
The Miller experiments created a few of the more simple amino acids and other simple
compounds by discharging electrodes into a mixture of methane, ammonia, water vapour
and hydrogen. Does this mean that perhaps amino acids could have been the first
components of the cell to form? Absolutely not. The first thing to keep in mind
is that laboratory experiments often differ from the real world in a number of ways.
Chemical problems
To begin with, Miller’s experiment used a flask equipped with a trap to collect
the amino acids. In textbook accounts, the trap is only described in passing, as
it was part of the apparatus he used. It is almost never mentioned that the trap
served to protect the amino acids from the same energy that was used to create them.
In fact, this energy would be many thousands of times more effective at destroying
these molecules than forming them. Some have proposed that tide pools, lakes or
clays may have served as traps on the early earth. ‘But solving the trap problem
would make another problem, because the molecules that must be protected from energy
sources also need that energy to advance to the next stage. Thus the idea of a trap
actually would be fatal to evolutionary theory.’1
But what if both amino acids and sugars were somehow able to beat all the incredible
odds and were not only able to exist, but to exist together? Dr Duane Gish, who
has extensive experience in forming proteins, says,2 ‘When amino acids and sugars are together
they combine so readily that they cancel each other out. … When an amino
acid and sugar bind in this way, the product is neither a sugar nor an amino acid.
That is, they chemically combine and destroy one another.’3 Gish says it is generally assumed that more amino
acids than sugars existed on the early earth. If this is the case, this would not
help evolutionists. All the amino acids would react with the available sugars and
there would be no sugars left to create the ‘backbone’ of the vital
coding molecule, DNA.
But let’s give the evolutionists the benefit of the doubt. Let’s concede
that sugars were somehow available and DNA formed. What would have happened to it?
‘Most evolutionists believe life first appeared in the ocean,’ says
Gish. ‘However, in water, nucleotides [individual units of DNA] don’t
come together but break apart through a process called hydrolysis. In this process,
energy is released. This is the opposite of what’s needed. To bring a DNA
molecule together, tremendous energy must be poured in to force those chemical bonds
to form.’
But for nucleotides to bond in the right way, they need energy as well as at least
100 enzymes (a type of protein) working together. This presents a ‘catch-22’
situation. The enzymes are needed to form DNA by combining its nucleotides, yet
these enzymes cannot be formed unless the DNA codes for them.
To suggest that one or two sub-units could have existed before the presence of a
living cell is totally fallacious. Rather, the living cell functions by an interdependence,
where one part depends on another.
Problems ignored
Not surprisingly, these incredible complications are censored from almost all biology
textbooks
Any search for a naturalistic explanation to the origin of life must confront and
try to answer the above unanswerable obstacles. Not surprisingly, these incredible
complications are censored from almost all biology textbooks. If this critical information
was included in biology curricula, the vast majority of students would have to conclude
that matter could not have changed itself into living things.
Furthermore, they would come to this conclusion based on what they know and can
see about the properties of matter. God never intended our plain and obvious origin
with Him to be a mystery. God said that we would clearly be able to see
His power and divinity in nature (Romans 1:20). The origin of life is mysterious only to the
one who has been exposed to all the facts, but ignores them in the hope of finding
a ‘God-free’ solution.
Telling your left hand from your right
Another often unmentioned fact of Miller’s experiments is that two types of
amino acids were created—they are mirror images of each other, just like your
two hands. Living systems are composed of only ‘left-handed’ amino acids.
However, in Miller’s experiment, and in any natural process, a 50:50 mixture
of left-and right-handed amino acids is produced. When both types of amino acids
are present, they chemically combine with one another in ways that make the resultant
protein totally inactive. Left to themselves, the amino acids produced in Miller’s
flask were nothing but evolutionary dead-ends.
Miller’s experiment failed to demonstrate how life’s exclusive preference
for left-handedness could have been achieved naturalistically. In an extensive interview,
Dr Gish explained how the natural behaviour of organic molecules poses insurmountable
problems for a naturalistic origin of life. ‘Without the presence of DNA to
direct the order of amino acids,’ says Gish, ‘the natural tendency is
that both types of amino acids would combine equally well with one another. There
is no tendency for left-handed ones to react only with left-handed ones.’1
By this he meant that the normal tendency would be that perhaps two or three left-handed
amino acids might attach together, then a right one, then maybe a left one and so
on. He says the problem with the presence of both types is that normal proteins
contain, on average, 400 amino acids. This means that by chance, 400 or so left-handed
amino acids would have had to come together without any right-handed ones.
‘If we had a protein with 400 amino acids,’ Gish explains, ‘the
probability of only all left-handed amino acids is ½ times itself 400 times
(½400 ) [or one in 4 x 10121 , which is a number so
large that it would be written as 4 followed by 121 zeroes]. If just one right-handed
amino acid were to bond with any of the other 400 left-handed amino acids, it would
render the whole chain inactive. It becomes inactive because right-handed amino
acids alter the shape of the chain. An enzyme [a special type of protein] must fold
in a very precise way in order to allow a substrate to attach to it. If a substrate
cannot attach to the enzyme, it becomes useless.’
Perhaps such useless proteins would have had a better chance if DNA had formed first.
Perhaps the sugars that have been created in other origin-of-life experiments could
have come together with phosphates and bases to produce the DNA. Like amino acids,
sugars occur in left-and right-handed forms. However, only right-handed forms of
sugars are found in living systems. The problem with the presence of both forms
is that it would prevent two complementary strands of DNA from coming together.
On this particular point, Gish makes a useful analogy, ‘Imagine a string of
right-handed gloves tied end-to-end and you want to insert a series of right hands
tied from end-to-end, but one of the hands was a left hand. The two could never
come together.’ If two complementary strands of DNA could not be joined, then
it would never conform into a double helix shape. Without this shape, DNA could
not replicate or perform any of the functions it now has.
Note
- Personal interview with biochemist Dr Duane Gish, 13 May 1996.
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References and notes
- Bliss, R., Parker, G. and Gish, D., Origin of Life, CLP Publishers, California,
USA, 1990. Return to Text.
- Personal interview, 13 May 1996. Dr Gish has a Ph.D. in Biochemistry, University
of California, Berkeley, and was Vice President of the Institute for Creation Research
in San Diego. Return to Text.
- The amino group (–NH2 ) in the amino acid reacts readily with the
carbonyl group (O=C<) in the sugar, releasing a water molecule (H20) to form an imine (HN=C<), which is useless for life. Return to Text.
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