In this section: Chance
or Design? • The Scientific Method •
Life in a Test Tube? • The
Eye • Irreducible Complexity •
Anything Can Happen? •
Evolution or Selection? • Real Examples of
Evolution • "Do You Feel Lucky?" •
(Abio)Genesis 1:1 • Life
from Comets? • Life on Mars? •
Richard Dawkins • A Brief
History of Slime...
... or
"Designer Genes"?
Self-organization or Intelligent Design?
In the 1950's, Miller and Urey performed a famous experiment
regarded by many as evidence that life could be the result of natural
processes. Let's take a look at
exactly what they created:
Tar |
Carboxylic acids |
Glycine,
C2H5NO2 |
Alanine,
C3H7NO2 |
Glutamic acid, Aspartic acid, Valine, Leucine, Serine, Proline,
Treonine |
|
|
|
85% |
13.0% |
1.05% |
0.85% |
Trace |
How life could begin mired in tar is a mystery itself, but Glycine and Alanine are
the simplest and most common of a group of molecules called
amino acids, which are indeed the building blocks of proteins found in living organisms.
So is this evidence of life? Well not exactly . . .
All living organisms have DNA, a very precise code of four molecules, each
quite a bit more complicated than the amino acids created by Miller and Urey:
So then this is life, right? Well not exactly . . .
These four molecules become part of a very complex double helix spiral
held together by other molecules yet, none of which have been produced in
such experiments. Adenine (A) pairs with thymine (T), while
cytosine (C) pairs with guanine (G). The two DNA strands are held together by weak
bonds between the AT and CG base pairs:
So then this is life, right? Well not exactly . . .
This represents only a very small section of DNA. DNA in even the
simplest bacteria have from 0.6 million to 4.7 million of these paired AT / CG bases in a
very precise order that encodes all the information necessary for building and maintaining
life. Each gene is comprised of segments of base pairs. Humans have 3 BILLION
paired bases that form their DNA.
If the DNA sequence of the human genome were compiled in books, the
equivalent of 200 volumes the size of a Manhattan telephone book (at 1000 pages each)
would be needed to hold it all.
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If unwound and tied together, the strands of DNA would stretch more than 5 feet but
would be only 50 trillionths of an inch wide. To put this in scale, if the strands
were magnified to one inch wide, their length would be 19 MILLION miles - 20% of the
distance to the sun. |
|
So then this is life, RIGHT? Well not exactly . . .
Each of these strands of DNA forms a chromosome. In higher
organisms, the chromosomes combine in pairs. Humans have 46 chromosomes arranged in
23 pairs.
So then THIS is life, right? Well not exactly . . .
DNA is just the program for life that exists in the
nucleus of each
living cell of an organism. Each cell is a miracle of
biological machinery in
itself:
Of course this is just a single "simple" cell. Humans are
made of roughly 75 TRILLION cells, each with its own unique design and purpose.
So then THIS must be life, right? Well not exactly . . .
An organism can have all this wonderful biological machinery in place and still not be
living. Once an organism is dead we know of no way to bring it to life. Even
with every physical component in place, there is no life unless all the life systems
(respiration, ingestion, digestion, excretion, reproduction, circulation, etc.) of the organism
all work simultaneously to create the miracle called life.
"The very best Miller-Urey chemistry, as we have seen, does not take us very along
the path to a living organism. A mixture of simple chemicals, even one enriched in a few
amino acids, no more resembles a bacterium than a small pile of real and nonsense words,
each written on an individual scrap of paper, resembles the complete works of
Shakespeare."
Dr. Robert Shapiro (Noted Chemist and Evolutionist)
The real working "building blocks" of life include a dozen sugars and
building blocks of lipids, which have never been formed in any significant
amount in Miller-Urey experiments, as well as proteins, polysaccharides,
nucleic acids and lipids, which have never been formed at all.
If our best application of intelligence and technology
falls so short of life, is it rational to assume that life could form
naturally or does this in itself suggest design?
Despite this, Scientific American in July 1999 proclaimed
"Life may owe its start to complex organic molecules
manufactured in the icy heart of an interstellar cloud."
The organic molecules commonly found in meteorites, however,
are still as far from "life" as the amino acids produced
forty years earlier in the Miller-Urey experiment. Most, such
as polycyclic aromatic hydrocarbons (PAH's), are even simpler.
Are we moving forwards, or backwards, in our understanding of life?
EXPLORE:
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EXPLORE:
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Is evolution fully supported by scientific reason?
In this section:
Chance or Design? •
The Scientific Method • Life in a Test Tube? •
The Eye • Irreducible
Complexity • Anything Can Happen? •
Evolution or Selection? •
Real Examples of Evolution • "Do You Feel Lucky?"
• (Abio)Genesis 1:1 • Life
from Comets? • Life on Mars? •
Richard Dawkins • A Brief
History of Slime...
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