[Marxism] Multiple solutions in evolution

Rod Holt rholt at planeteria.net
Wed Aug 24 21:40:01 MDT 2005

For those interested in evolution and/or “intelligent design” I 
recommend an excellent article by Henry Gee, part of which is reproduced 
below. Understanding the rather anarchic nature of nature is important.
Published online: 07 July 2004; | doi:10.1038/news040705-1
muse at nature.com:

The tyranny of design
by Henry Gee
We are accustomed to thinking of ourselves as peaks of perfection, and 
the arrangements of more "primitive" creatures as similar to our own, 
only cruder. It's a nice idea. Until along comes the sea lamprey to 
challenge our preconceptions.

Researchers have found that the lamprey (Petromyzon marinus) has a has a 
sophisticated system of adaptive immunity, that is entirely different to 
our own. Many organisms have a kind of natural immunity, but the 
adaptive immunity of mammals was supposed to be something special. By 
dint of a kind of controlled chaos, specialized parts of our genomes 
rearrange themselves to produce antibodies, custom-built proteins that 
are then selected to target any kind of foreign molecule the world can 
throw at us.

One of the great mysteries of immunology is how and when this remarkable 
system originated. For many years, immunologists looked for its 
beginnings in lampreys, sucker-mouthed creatures that represent the 
earliest flourish of vertebrate evolution more than 500 million years 
ago. Lacking jaws and paired fins, lampreys are almost as primitive as a 
vertebrate can get. They seem to have adaptive immunity, but scientists 
haven't found even a glimmer of any antibodies.

The discovery, reported by Max Cooper and colleagues in Nature this 
week, that lampreys have developed a perfectly respectable adaptive 
immune system all by themselves shows that the problem lies not with 
evolution itself but more with the way we think about it. Alas, we 
humans do not represent the pinnacle of design to which all other 
species aspire. Collins' work shows us, once again, that evolution 
experiments with various solutions to life's problems, only some of 
which stay the course. There never was only one system of adaptive 
immunity: thanks to the lamprey we now know that there were at least 
two, and possibly many more, now extinct, or remaining to be discovered.

There never was only one solution to adaptive immunity: thanks to the 
lamprey we now know there were at least two.

Intelligent design?

The fact that the work seems so surprising exposes another, more 
dangerous conceit that scientists are prone to. Dangerous, because it 
leaves science wide open to the temptations of so-called 'Intelligent 
Design'. Advocates of this view object to evolution by invoking what 
Richard Dawkins has called the 'Argument from Incredulity' – that is, if 
I don't believe that something is possible, it cannot happen. 
Philosopher William Paley in his Natural Theology famously used this 
argument when he compared the delicate designs of nature with a pocket 
watch. Pocket watches are not made spontaneously, so if the existence of 
a functioning, integrated watch implies a watchmaker, then the same must 
surely apply to a living creature.

More than a century later, proponents of Intelligent Design use the same 
reasoning when they marvel at the intricate design of, say, a bacterial 
flagellar motor. How can one ever give credence to the view that the 
sophisticated mechanism of the flagellar motor could have evolved to 
such precision without a guiding hand, when the tiniest of changes to 
its apparently irreducible complexity might render it useless?

I was discussing the problem with two polymathic friends of mine, 
reproductive biologist Jack Cohen and mathematician Ian Stewart, 
co-authors of Figments of Reality, Evolving the Alien and The Science of 
Discworld. They are working on their next book, Appearance of Design (to 
be published by Penguin next year) and Cohen sent me a draft chapter 
containing a devastating response to the challenge of Intelligent 
Design. It arrived on my desk at about the time that the work on the 
lamprey immune system was making waves in the Nature office, so it 
struck a particular chord with me.

Cohen argues that the fallacy in the Intelligent-Design argument about 
the flagellar motor (or any other system), is that proponents present 
the motor we see as The Motor, the exemplar, the only one possible, and, 
what's more the best possible, surely optimized by a Designing Hand. But 
when Cohen searched the literature, he found that a wide variety of 
flagellar motors have been described, each arranged in its own way, each 
its own solution to effective rotary motion in the microworld. There is 
no such thing as The Motor, no Platonic perfection enforced on bacteria 
by Divine fiat. Instead we see ad hoc solutions that are not perfect, 
but idiosyncratic and eclectic – just what you would expect if evolution 
were working on its own, without a Designer.

[complete at http://www.nature.com/news/2004/040705/full/040705-1.html
And it’s free, I hope. If not, let me know

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