Post by Teresita Post by Andrew
Nothing from the fact that living things are made up of proteins,
and biological proteins are synthesized only within a mechanism
that has been specifically designed for them to do so. That is an
established fact of molecular biology, which is positive evidence
for a Creator.
Ah, yes, the ol' irreducible complexity ploy. That's refuted by the
Imagine there is a small river in the mountains marked by boulders and
debris from falling trees. Now imagine that at one place a rolling stone
finds a stable position on the left bank. That’s one mutation. Later,
another rolling stone finds a stable position on the right bank opposite
the first one. That’s the second mutation. Still later, a third rolling
stone happens to settle in between the two . By a series of three single
steps, completely random, we now have a useful “organ” in the form of a
kind of primitive bridge. It is possible to cross the stream at that
location by hopping along the three stones. Statistically, such an
arrangement of three stones in a line, though rare, is bound to happen.
Now imagine that a log floating in the river reaches these three stones
and becomes wedged against them. So we have two bridges existing
side-by-side, but the log bridge is better than the stone bridge because
people don’t have to risk their neck jumping from one stone to another.
This is a mutation that results in an improvement to the “organ”.
Travelers end up preferring the log to the stones, and their many
crossings depress the ends of the log into the river bank, making it very
Now imagine that the river flowing under the log washes the three stones
away one after the other, leaving only the log. Many generations later,
people come out and admire this Cadillac of a bridge and remark that it
must have had a bridge maker. It couldn’t possibly have formed by
chance, because even if one end of the log happened to wedge in a
riverbank by chance, the other end would be bent by the stream and the
whole log would have swept away. The bridge would be offered by
proponents of the Intelligent Bridgemaker as an example of irreducible
complexity, and yet, as was shown, the real history of the bridge was a
series of single steps, made by nature entirely by chance, but reinforced
by the improvements made to its fitness as a bridge.
It gets worse for Andie.
LIFE MAKES MORE of itself.
And now so can a set of custom-designed chemicals. Chemists have shown
that a group of synthetic enzymes replicated, competed and evolved much
like a natural ecosystem, but without life or cells.
"So long as you provide the building blocks and the starter seed, it goes
forever," said Gerald Joyce, a chemist at the Scripps Research Institute
and co-author of the paper published Thursday in Science. "It is
immortalized molecular information."
19 April 2012
Enzymes grow artificial DNA
Synthetic strands with different backbones replicate and evolve just like
the real thing.
Gerald F. Joyce and David P. Horning report having produced an RNA enzyme
that both synthesizes complicated functional RNA molecules and replicates
simpler RNA molecules. This effort is quantitatively different from
earlier work that produced only simple RNA, Joyce said.
The evolved enzyme, called a ribozyme, was selected for its ability to
make functional RNA, but it cannot reproduce itself. Work toward that end
continues, Joyce said. Such a self-replicating molecule would meet the
essential criteria for life, he said.
Self-replicating RNA is hypothesized to have existing before DNA, which
carries the code of life in all living organisms. This "RNA world" is
thought to have given way to DNA billions of years ago. Its existence is
inferred from the properties of RNA, which acts both as a transmitter of
genetic information and an enzyme that can perform functions of some proteins.
19 April 2012