Plantinga
has, along with Humble Don and the Shaved Chimp and many other apologists, tried
to argue something along these lines:
Proper
function of the heart is the pumping blood around the body.
If
the heart fails to pump blood around the body, the owner of the said heart
dies.
However,
proper function implies conformance with specifications, which in turn implies
a designer.
Therefore,
god exists, or you die of heart failure … your choice.
Ironically,
Plantinga had a triple bypass operation earlier this year (discovered when
trying to find his quote using the string “Plantinga and the heart”). Thank god for those surgeons, eh?
The
idea behind this argument is that the human heart (or whatever human organ you
want to use) does a particular job, and apparently does it exceptionally
well. Without it we would die – unless
science stepped in. But if you are going
to argue along evolutionary lines, what did the heart do before it pumped
blood? How did it get from there to
where it is today?
This
is sort of where the argument of “irreducible complexity” tries to get
purchase. One can understand how a heart
might scale up along with the owners. A
small shrew-like mammal precursor would not need the half-kilo heart that
humans carry around with them.
However,
there comes a point where there are simply not enough cells in a heart to
support any pumping at all. In the
“irreducible complexity” argument there is a gap between a few cells joining up
together and not doing anything particularly important, and a quite large
number of cells being assembled with the express purpose of pumping (the
smallest known mammal has a heart which weighs about 15mg which comprises in
the order of half a billion cells).
People like Plantinga try to slot god into this gap.
A
problem with this argument (apart from the fact that the mammalian precursor
had a lineage which included smaller creatures with smaller heart like
structures – for example insects, the smallest known of which is 0.139mm long)
is that it assumes a continuity of function.
Nature doesn’t seem to consider itself thus constrained. For example, scales and feathers and fur are
variants of the same basic thing, petals and leaves and thorns are variants of
the same thing. Plants didn’t
specifically develop “pointy things to dissuade grazing animals”, they simply
co-opted and perfected pointier than average leaves. (Don’t take this too literally – there was no
Supreme Council of Plants with a 1,000 Year Plan to develop thorns.)
The
problem comes in when you assume design and you assume that a function that you
are bright enough to recognise must have been designed in (and you’re not
overly bright). This is understandable,
to a certain extent, in a technological society like ours. Everything is designed with function in mind
(and somewhere close to half of the population are of below average
intelligence – not my readers of course, you are all brilliant).
However,
getting back on track … I draw your attention to the Swiss Army knife. This is a perfect example of something specifically
designed for one purpose being co-opted for another.
My
variant of the Swiss Army knife has a number of goodies:
two
sharp blades – occasionally used
(when I can’t be bothered getting
a proper knife)
two
screwdrivers – occasionally used
(when I can’t be bothered getting
my screwdriver set)
a
corkscrew – never used (I have better corkscrews around)
a
fish-scaler – never used
a
helping you to tie fishing line thingie – never used
a
thingie for getting stones out of horses hooves (I assume) – never used
a
can opener – never used
a
toothpick – lost and never used
a
tiny pair or tweezers – never used
a
little pair of grips – occasionally used
(when I can’t be bothered getting
my socket set)
solid
construction (ie a hammer) – occasionally used
(when I can’t be bothered getting
anything more hammer-like)
a
lovely pair of scissors – used all the freaking time to cut my nails
In
terms of evolution, the Swiss Army knife is in a transitional state between
being something which does various things not particularly well into a
magnificent device that appears to be designed specifically for cutting
nails. Nothing cuts nails better.
Now,
I am pretty sure that the gnomes in Switzerland are not designing towards a
perfect pair of nail scissors. They are
just churning out variants of their product, trying to maximise sales. All that has happened is that I, representing
natural selection, have favoured a variant of the Swiss Army knife which
performs a key task well. If the vast
majority of Swiss Army knife buyers, like me, purchase them primarily to cut
their nails, and a later design change eliminates that function, the Swiss Army
knife will die out. If a later design
change maintains the heft of the Swiss Army knife and the scissors but removes
unnecessary stuff like the fish-scaler and thus improves its attractiveness on
price, then it will become more popular at the expense of more awkward
variants.
I
suggest that the same thing happened with the heart. A bunch of cells were already huddled
together with some other goal in mind, or even a range of goals, (entirely
metaphorically, cells don’t huddle and they don’t have intentions) before being
co-opted into the pumping blood malarkey.
(Similarly,
at a much smaller scale, the supposed “irreducible complexity” involved in the
inner workings of a cell would also have involved the co-opting of an existing
function.)
So, as a last word,
if something that was specifically designed for a purpose, like the Swiss Army
knife being designed to deprive tourists of their hard-earned Euros, can be
co-opted for another purpose, like cutting my toe-nails, then it is surely not
too much of a stretch to think that non-directed “design” could co-opt existing
structures and modify them to suit a new purpose. Is it?
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