The idea that evolution is genetic chance and environmental necessity is a
good one, but not entirely accurate without qualifications. One
qualification is that the environment must include the environment of the
genes themselves, including other genes. Another is that the term "chance"
must be taken to mean "free of direction by a mind."
It must *not* mean metaphysically random, and it must not mean without any
constraints or limiting factors.
This, I think, is so deeply taken for granted by supporters of naturalistic
evolutionary theory (or NET) that they may not even think to articulate it.
They may not even be conscious of it.
What I will outline here are *seven* important respects in which the
evolutionary process is or at least may be non-random. These seven respects
all give, superficially, the "look" of intelligence to the process, because
the results differ so much from what would be expected if the process
*were* truly random. Nevertheless, they are all mere mechanisms, as dumb as
oatmeal.
We might not need to consider these respects were it not for the fact that
there is an absolutely amazing tendency among creationists and other ID
theorists to equate "chance" with some very bizarre ideas, such as the idea
that a tornado could swirl through a junkyard full of Boeing 747 parts and,
"by chance," assemble a perfectly working Boeing 747. Of course, no NET
support has ever seriously said or meant to say such a thing, and none have
ever said or meant to say anything that would imply such a ludicrous notion
of chance in relation to evolution. Nevertheless, this example has become a
mainstay of creationist/ID rhetoric, despite the blindingly *obvious*
invalidity of the metaphor with respect to any actual mainstream variant of
NET. I'm not sure why. I suppose that all of the people who have used this
example would claim to have made an honest mistake. Such a mistake is,
however, like shooting a person twelve times with a six-shot revolver and
then claiming that it all twelve shots were accidental (and that the
revolver "accidentally" got reloaded after the first six shots).
Nevertheless, I thought I'd remove any potential excuse for such "mistakes"
by listing and describing six ways in which the evolutionary process is
*not* random, and by carefully specifying the respect and sense in which it
*is* supposed to be random or a chance process. I hope all of those on this
list who have used the 747 example or ones like it will read this and take
note.
I also hope those who pretend that the only alternatives are randomness
*or* intelligence will take note as well, since their claims are often
nearly as off-base as are those who *do* use the 747 example.
Okay, here we go.
1. Selection is not random. This is *blatantly* obvious, but, in case
someone does not see it, consider what it would mean if selection *were*
random. It would mean, among other things that, if we replaced 500 polar
bears with *camels*, the camels should to *just* as well in the arctic
climate and water as did the polar bears, which should fare just as well as
camels in the Sahara desert.
Selection cannot be random because it depends on non-quantum level aspects
of biology and physics, such as factors like temperature, the presence of
prey and/or predators, disease, water supplies, and so on. Even in our
daily lives, it is obvious that selection is not random. The dog who gets
hit by a car is the one that has not learned to avoid getting hit by cars,
and this depends on factors such as intelligence, temperament, speed and
agility, hearing, sight, and so on, all of which are at least *largely*
determined by genetics, not by metaphysical dice. Even fur-color, a genetic
trait, can make all the difference between getting run over on a dark road
and *not* getting run over on a dark road. Similar considerations apply to
plants and to almost any kind of living thing that we have any daily
observational knowledge of, such as birds and insects.
This non-randomness of selection is why selection is such a powerful,
albeit non-creative, factor in determining what organisms there are out of
all *possible* organisms. Selection trims away the ones that do not have
the functionality required for survival. This includes all the ones that
don't have sufficient organization in their components (from the atomic
level on up) to be functional as well as many that could be functional in a
different environment but not in the one they happen to find themselves in.
Therefore, whether they are designed or not, the *surviving* organisms
*must* have an appearance that is similar (at least superficially) to
something that is designed. (More accurately, things that we design for a
functional purpose must appear to a degree to be similar to things that are
functional for whatever reasons, designed or not.)
2. Implicit in the above, but also applying to the DNA-replication process,
are the laws of physics. The components of DNA are restricted, essentially,
to the four nucleotides involved. We don't see bits of DNA with a
nucleotide replaced by a lump of gold, or by molecular components that are
chemically incompatible with the DNA molecular context. In general, the
DNA-replication process cannot occur or becomes abnormal if the temperature
is too high or too low, if there are significant amounts of certain
chemical "intruders," if the components are being bombarded by gamma rays
at such a rate that structural maintenance is impossible, if the molecular
context is vibrating at certain frequencies and energies, if there is too
much light, if important components are missing from the molecular
environment, and so on.
I would guess that one reason some bacteria seem to produce more genetic
variations when they are in an insufficient-nutrient environment is that
the nutrients required to stabilize the DNA-replication process are in
short supply, and so it does not work as well, thus permitting more than
the usual amount of genetic variation to occur. Some would like to
attribute this increased variation to intelligence, but the simple
reduction in stabilization due to the lack of certain nutrients is a much
more elegant hypothesis because it does not require the introduction of
otherwise unseen intelligence, and because it automatically links the
reduction in nutrients to the increase in variation. Further, it lends
itself to empirical testing, whereas the ID alternative does not, except in
special cases.
3. Physics and chemistry restrict the currently possible variations that
can occur in any case of DNA-replication. A bacterium will not produce, in
one generation, a human genome or anything much like a human genome. Why?
Because the resources for such a monstrous undertaking are not present in
the bacterium. What *is* present are resources for much less demanding
modifications, such as an increase in some internally-useful compound, or a
modified gene for producing one thing such that it will now also produce
something else that benefits the bacterium, etc.
In all cases, what a genotype is now will severely restrict what its
offspring can be. Thus, all immediately possible changes form a kind of
probability gradient such that the more radical changes are also the less
likely ones.
And *this* means that the probability of a change occurring that *is*
beneficial is much higher than it would be if just *any* genotype could be
the offspring of a particular genotype. Why? Because the current genotype
is fit for its current environment (otherwise it would not be reproducing
at all), and since any change that occur in its offspring will *also* have
a relatively high probability of being fit for that environment, more or
less. If just *any* genotype could be the immediate offspring of a given
genotype, there would be a *much* greater chance that it would be suited
only for some radically *different* environment (or that it would not be
biologically viable at all).
4. The "computer" that copies the genotype at replication time must be
matched to the genotype that it is to reproduce. It does not always have to
be a perfect match, but there must be a match, nevertheless. Replacing a
bacterium's genotype with a human genotype would not enable the bacterium
to produce a human being as its offspring. This means that changes that are
too radical for the "computer" will not produce viable offspring. And
*this* means that the only offspring of an organism that we *will* see are
those that *do* fall within the range of variations that the "computer" can
adequately process. Again, to the naive, this may look like intelligence,
when all it is is a lack of capacity to produce viable radically different
offspring.
5. At some point in evolutionary history, many lineages (including those of
many if not most bacteria) evolved mechanisms that protected against or
corrected some errors in DNA-replication. Initially, this was merely
another tiny genetic accident, but once it occurred, it tended to reinforce
itself by virtue of the fact that the more successful variants of such
mechanisms would be the ones that would be still reproducing, and the
others would have bred themselves out of existence. Thus, each minor
improvement on the selectivity and usefulness of such a mechanism would
tend to be saved while failures would tend to disappear.
The result is, again, the pseudo-appearance of "intelligence" without the
need for any *actual* intelligence. This is because the mechanisms of this
sort that behaved most appropriately would be the ones left, the ones that
were producing the best range of variations and preventing the worst
variations (as long as the environment doesn't vary in such an extreme way
that the mechanism actually prevents *needed* variations, of course).
6. Another factor is that some lineages may evolve mechanisms that
*increase* variation in other parts of the genome, thus providing
themselves with more opportunities for survival as long as *some* of the
new genotypes survived. Sex appears to be just such a mechanism, because it
allows wholesale recombination of those genes that differ from one organism
to another of the same "species," thus allowing for a wider range of
*general* variation without depending on "errors" in the DNA-replication
process to introduce variations. With DNA recombination, a major variation
mechanism is built right into the reproductive process.
And yet, even *these* variations are by no means completely random,
because, for one thing, every piece of every genotype exists in a
biologically viable organism (or there would be no reproduction of them
going on at all). This means that each gene in each organism is at least
*partially* "field tested" and found viable. And *this* means that it has a
*much* higher chance of being viable in an offspring organism, even if
other genes are also different, than it would if it were a gene appearing
for the very first time. A gene appearing for the very first time has a
much greater chance of causing harm than one that has been tested at least
for one generation and that has not been found to be fatal. Of course, the
ones that *are* found to be fatal are not around to reproduce.
The result is that nearly every member of the species may be viable and yet
still differ significantly from most other members of the same species.
This is the case with human beings, for example.
And, again, to some, this might look like intelligence, but all it is is
the increase in "safe" variation via a blind mechanism (sexual
recombination) which, once it begins to occur, tends to come to dominate
those genomes that have it at all. And, once it *does* become solidly
established, any other genes that seriously interfere with it ultimately
interfere with their own survival, so we will not find many genes left that
*do* interfere in a major way with this mechanism. By blocking
reproduction, they block their *own* reproduction, too, so it never works
out well. Genes that *help* the sexual recombination mechanism, on the
other hand, will tend to guaranteeing their own continued reproduction.
7. Finally, there is the "genetic library" that exists in many organisms.
This "library" provides a collection of genes that can be and occasionally
are activated. When one of them is activated, it may be fatal, but, if the
circumstances of the species are changing in the right ways, it may be a
*benefit* to the organism to have this gene activated. The advantage of
such a "library" is that it is a repository of pre-tested genes that worked
in the past and that may work again in the future if conditions change.
Because all that is needed to activate such a gene is a relatively minor
"switching" gene, the long evolutionary process that originally produced
such a gene does not have to be repeated, so the gene can become active
throughout a population in a relatively very small number of generations,
if need be. I suspect that the size changes of the famous beaks of the
famous finches is of this sort.
But, the library can also provide material for *new* genes, material that
can be reactivated and then modified through a relatively few steps to
produce a truly new gene that does something not done at all by prior genes.
And, it can provide genes that can be activated in *combinations* that have
never been tried before, or combined with true mutations, and so on.
And, once again, this will look like some kind of intelligence to the
person who simply *must* have intelligence lurking in every nook and cranny
of Nature, even though the activation process may be blindly accidental as
it is theoretically possible for it to be.
In all seven of the above respects in which evolution is neither
intelligent nor random, the result is a dramatic increase in the ratio of
beneficial to non-beneficial modifications that are likely to occur during
replication.
There is one *more* type of event that I should mention also:
8. DNA is often modified in small ways between the time it is created as
offspring and the time it is used in generating its own offspring. It is
known that some organisms have mechanisms for protecting themselves against
many such changes, but not against *all* such changes. For example some
organisms are many times more resistant to radiation damage than others,
because they have powerful gene-repair mechanisms. I suppose these evolved
with the gradual evolution of ordinary organisms in environments of
progressively higher levels of natural radioactivity.
I don't know. But, the point is that things that happen to genes even when
they are *not* being replicated can make a difference in the genetic makeup
of the offspring, and there will be a tendency for genomes to evolve
mechanisms that protect them against any such changes that will prevent
further reproduction. Thus, a gene that appears that results in the death
of the organism *after* its final reproductive cycle is completed may be
allowed to go on indefinitely, while a gene that results in the death of
the organism *prior* to reproduction will tend to be weeded out.
This will have the appearance to the naive of "smart genes" that know to
become active only after the organism's reproductive period is over, even
though all it is is that such genes were not weeded out while the ones that
were fatal earlier in the organism's life were weeded out because they
blindly prevented their own reproduction.
All of these mechanisms and types of mechanisms are blindly mechanical, as
far as we can tell. But, by virtue of greatly increasing the frequency of
the appearance of beneficial modifications over the frequency of beneficial
modifications that would be produced by truly random processes, they give
an appearance similar to a certain (low) level of intelligence.
Perhaps it is this sort of thing that makes it easy for so many people to
think that evolution is guided by some kind of intelligence rather than by
naturalistic variation.
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