There are religio-political factions who wish to have the teaching of Darwin's
theory of evolution in public schools suppressed in favour of a theory
of
intelligent design
. The basic crux of their argument is that: there
remain controversies in science, which they ask us to interpret as grounds for
doubt about the basic tenets shared by the assorted parties to these
controversies; in the presence of such doubt, they ask us to accept without
critical thought a set of claims they present that they claim are as valid as
the basic tenets shared among those whose controversies they pointed to.
There is absoluptly no basis for that argument. Even if you could prove that evolution was outright wrong, that would not amount to a single jot of data towards establishing any other theory. It would leave a space open for other theories to attempt to claim, but they would have to stand up to at least as rigorous a critique as the ousted theory. If you do not provide any evidence for your own pet theory, no amount of evidence against an incumbent theory is any help in persuading science to accept your theory.
Howevever, let waste no more time with tha intelligent design
camp's
failure to say anything testably true and at odds with the theory for which they
claim to be a substitute. The fundamental failing of intelligent design
is that it is not a theory.
We would, of course, like our theories
to deliver everything: a
complete description and explanation of everything (at least within their domain
of relevance), sufficient to predict everything. In practice we don't have many
of those outside the formal domain of mathematics, where Humpty-Dumpty is King:
if you are at liberty to make up your own rules, sometimes you can decisively
answer some of the questions those rules admit you should be able to answer.
Science develops theories which attain as much as is practical of that precious
goal: a theory need not be perfect to be good, illuminating and, crucially,
useful.
So, realistically, what should we expect of a theory ?
On all three of these things, intelligent design
fails
abysmally. It does not matter what faults in the best available theory
you are able to point to, if what you claim to be offering in its place is not
better, then it is not worthy of being taught as a credible
alternative
. When it is not even a theory, it is not an alternative at all,
let alone a credible one.
The proponents of intelligent design
endeavour to account for the
emergence of the most basic forms of life by postulating a form of sentient
intelligence significantly more complex and sophisticated than the life-forms we
are actually able to document as existing on our home planet. It claims to
account for simple things by asking us to believe in something vastly more
complex than the things we know exist. The reverse might qualify it as a
theory: being the wrong way round is just silly. Since its proposed
explanation
adds another thing – the designer
– whose
existence it fails to explain, it actually leaves more to be explained, after
its attempt at explanation, than before.
The only questions the proponents of intelligent design
are able to
claim they answer are those whose answers we knew before they prposed their
answers. They give us no questions that we can answer and report back to
our peers: the only questions they claim to be able to answer are
intelligent designer
The former says nothing: the latter tells me that they understand primate social dynamics – despite denying its relevance – well enough to apply it to the social insecurities of their audience. One might forgive them the former as delusion and stupidity: but the latter smacks of outright cynical manipulation. Science sets out to change someone's mind by presenting evidence and reasoned argument; when someone tries to bring me round to their way of doing things by bribery and threats, I tend to suspect they are aware that they cannot live up to that simple standard; and even that they came by their beliefs by the same means they attempt to use on my, not by any form of reasoned enquiery.
The proponents of intelligent design
make a lot of noise about the
fact that science is unable to give a blow-by-blow account of every single
molecular change in the early history of life on our home planet; and they make
much of their claims that they know exactly everything that happened in the
course of life's emergence from a universe without life. Science is rightly
contemptuous of their sound and fury, on both sides. We have almost no data at
our disposal as concerns the earliest history of life's emergence: furthermore,
we have ample grounds to expect that we should have little data on this
point. Science's account of the matter postulates simple life-forms being
dominant until the emergence of such complex life-forms as have differentiated
body parts (without which there are no fossils). Science doesn't claim to know
any details before such recordable details existed: but has several
candidate accounts – of how the origin of life might hasve
proceeded – that fit well with its account of the matters about which it
does make definite claims.
The proponents of intelligent design
claim to have a full account of
how everything went, from the get-go: but they wholly and utterly fail to answer
any questions at all about the molecular changes leading to life as we
know it. Quite apart from their abject failure to account for the
existence of the intelligent designer
, they also utterly fail to account
for – or even provide a framework within which to account for – the
very things they complain against Darwinism for failing to do. They are unable
to explain the things we do observe, yet make very clear and definite claims
concerning matters about which we have least knowledge.
Science makes definite and testable statements about the world we live in,
fits these into a coherent model and observes that extrapolating this model can
credibly give answers that we cannot test; intelligent design
makes an
entirely untestable claim about something we cannot test, and extrapolates from
it various nebulous claims about how we should live our lives but nothing about
the actual nature of life as we find it in the world today, let alone anything
testable. Its proponents have the gall to complain that science reports some of
the things it can extrapolate about matters we cannot test: but only science has
anything useful to tell us about our world.
Have you accually looked at life in detail ? If you claim it arose from
intelligent design
it's about time you did. Proponents of this idiotic
scheme claim that the eye is a prime example of how stuff couldn't arise by an
evolutionary approach so must require an intelligent designer
.
They make this claim despite the clear and well-documented analysis by which
assorted proponents of Darwin's science have explained the evolution of the
chordate eye. But wait a minute: the chordate eye (what you and me have, along
with loads of other fish, reptiles and mammals) has a huge and stupid design
flaw in it. We have a blind spot. Surely an intelligent designer
wouldn't make such a ridiculous mistake ?
Proponents of intelligent design
argue that half an
eye would be no use at all
– revealing that they haven't understood
the theory they're trying to undermine. In the land of the blind men, the
one-eyed man is king: just so, in a world populated by sightless creatures, the
fish with light-sensitive tissue under patches of its skin has some advantage
over those without – it gets clues, however poor, about its surroundings.
The story never goes via half an eye: it goes via a succession of slightly
better ways of making use of a patch of skin with light-sensitive tissue under
it. It works better if the skin is more transparent. It works better if the
light-sensitive layer dimples inwards (which gives better directional
sensitivity). For the outer surface to keep its shape, that requires the skin
to be thicker; and if it's not very transparent that doesn't work well; so
trapping a layer of water between skin and light-sensitive tissue works better.
This makes it easy for the inward dimple to go further and, by forming a cavity,
attain much better sensitivity to direction. Subtle variations in the thickness
of the layer of transparent skin then confer further advantages by focusing the
light; each improvement makes this better until a lens is formed. At each step
along the way, a modest change in something pre-existing yields some advantage,
that advantage translates itself to a larger population exhibiting the new trait
and sets the stage for further changes. But let us leave aside the evolutionary
explanation and turn to what we may infer, if we suppose the eye to have been
designed, about its designer.
Any idiot designing a system for collecting light, focussing it to an image and collecting the image data for processing by an information-processing system would, as a matter of course, given basic knowledge of optics, put together a lens (or a bunch of boundaries between optical media of differing refractive indexes, which amounts to the same thing, but can be flexible), a hole in which to mount it (ideally with some scope for varying its apperture, so as to balance the competing requirements of more light but finer focus) as light's sole entrance to an otherwise dark cavity and an image capture system, wired to whatever image=processing system is intended to be receiving the results. Any designer would rapidly enough realise these aspects of the design are necessary. But only an idiot designer would have the wiring from the image-capture system (i.e. screen sensitive to light) intrude into the darkened cavity through which the light has to pass from lens to image-capture screen. The most blindingly obvious solution, which even a quite severely dumb designer can reasonably be expected to come up with, is to have the image capture aparatus receive light from one side (the cavity) and have its wiring go out to the image-processing system from its other side.
Now, of course, it's conceivable that this Obviously Correct Solution to the
problem is impossible to implement, for one reason or another: in that case, one
could accept that even an intelligent designer might roll out a design
containing the defect of an image-capture apparaturs in which the wiring
which carries information to the image-processing infrastructure must compromise
its effectiveness as a data-transport in order to be transparent
and have
exactly the same refractive index as the medium into which it intrudes;
only in such circumstances could one countenance an even half-way competent
designer lumbering us with an eye in which part of the image-capture screen has
to have a significant hole in it to let the wiring
out. Otherwise,
imposing these burdens on its deeign would be preposterous. It would be obvious
to an idiot that having the wiring go out of the back of the eye would
let the eye collect its image from the whole screen, without any need
for a hole and consequent blind-spot. Any half-way competent designer would
also realise that the wiring is bound to wear out: if it has to intrude into the
image-forming light-path, even if it is transparent and does
have the same refractive index as its context, the fragments into which it falls
apart are going to mess up the image.
Well, guess what ? Squids, octopuses and kindred creatures have exactly the
kind of eye that an even half-way competent designer would come up
with; so we know it's not impossible. Only these cartilaginous sea
creatures have that kind of eye: every kind of creature that has a back-bone
– a spinal column, or notochord
, marking its owner as a member of
the broad classification chordata
– has the exact same stupid bug
in its eye's design
as we have, which lumbers us all with a
blind spot in each eye – because the nerve fibres carrying signals from
our retinas to our brains intrude into the eye's light-path (instead of simply
going out the back of the retina) and so need a hole in the retina through which
to be bundled. We also have minor visual problems (they get quite severe for
some folks) caused by fragments of dead nerve cell floating about in the
light-path of the eye, messing up what we see. The cartillagenous sea creatures
are ample proof that the correct solution is possible: yet everything
with a back-bone has an eye whose retina is wired back-to-front.
Evolution explains the association of the mis-designed eye
with the notochord quite straight-forwardly. Since the nervous system mostly
needs to report on the outside world, it has rare tendrils that go out to the
skin and a rich network of tendrils running just under the skin. It then
suffices to have some early chordate creature with a light-sensitive layer
slightly further under the skin, so that the nerve cells are just outside it;
that would suffice to leave the nerve cells on the outward side of the
light-sensitive tissue for the rest of the story, accounting neatly for the
inconvenience of our blind spot. No sequence of small adjustments starting from
there can get to the right way round
eye without going via forms of eye
which are worse than the one we have, so evolution will never fix it. Given an
early chordate species with half-way decent eyes, marred by a blind spot for
these reasons, evolution predicts that all its descendants will be chordate and
have eyes with this defect.
Now, if life had a designer, who clearly Got It Right for the cuttle-fish
and their cousins, one must reasonably ask why the designer chose not to use
that design for chordate creatures. Furthermore, it is reasonable to ask why
this design decision exactly correlates with the decision to include a
notochord. Why do we see no cartilaginous sea creatures whose retinas are back
to front, and no chordate animals with eyes the right way round ? The designer
suddenly seems very whimsical in light of this: and it only gets worse when we
observe the myriad of other little details – the more of them two species
have in common, the more closely they generally match one another. If we
consider two quite different traits – the detailed molecular structure of
the gene coding for some standard enzyme involved in the Oxygen cycle of all
cells, say, and the shape of the pieces of bone at the upper ends of the jaw
– we find that similarity in one trait is generally closely correlated
with similarity in the other. How can intelligent design
explain these
correlations ? Of course, good design does re-use patterns in many places; but
it has no reason to restrict where it re-uses patterns in such a tighly
correlated way: departing from the correlations would offer many ways to design
better creatures – like owls and humans without blind spots.
Resorting to The Lord moves in Mysterious ways
is nothing but a
cop-out: it amounts to saying our so-called theory has no predictive power,
please stop asking us to use it for the single purpose that would give science
some reason to pay any attention to it.
You are welcome to your religion:
just please don't mess up science by asking us to teach a really dumb
mis-interpretation of a Judaic folk story as if it were science
when it,
quite plainly, isn't.