X-Message-Number: 20269
From: "Brett Bellmore" <>
Subject: Re: CryoNet #20259 Biology vs engineering
Date: Tue, 8 Oct 2002 21:28:52 -0400

"From: Thomas Donaldson >for Mark Plus:

"First of all, the superiority of "electrical machines" over
"organic machines" such as us isn't clear at all. The major
advantage that organic machines have is an ability at self-repair,
which in our case will become more and more over time. Moreover,
life forms do one major thing our machines do not do: they can
repair themselves."

Clearly, there isn't any logical reason we can't make our machines capable
of self-repair. It could be argued that a self repairing, self-reproducting
machine would be a form of life, however. Perhaps more to the point, a
processor capable of being self-repaired while it's running obviously
couldn't be as dense as one which contained only processing elements.

"As for speed, life forms have been around for billions of years, and large
for millions of years. If speed of reaction were important, then they would
have evolved much
more electrical and fewer chemical connections."

Thomas, I think you're discounting one of the fundamental weaknesses of
evolution compared to conscious design: Pathway dependence. Or to put it in
another way, evolution is a hill climbing algorithim, and it is subject to
hanging on local maxima, whereas conscious design can cross valleys to more
global maxima.

A classic example of something which could be improved about human biology,
but which evolution can't improve, is the backwards nature of the retina.
The light sensitive cells are at the back of the retina, data processing
occurs in front of them, and at the very front of the retina are the fibers
collecting that data, which converge on the center of the retina, leaving a
hole, our "blind spot", in which we can't image anything. (Not to mention
that all the light has to pass through the retina before it can be detected,
constraining those cells to be transparent.)

Now, it's blatently obvious that having a hole in your visual field is
contra-survival. But evolution can not in a million years remove the blind
spot, because it dates back to a time when our eyes were just light
sensitive spots that didn't have to image, and at that time it got locked in
topologically in our fundamental morphology. There's simply no way for
evolution to invert the retina, and remove the blind spot, because too many
genes would have to mutate at once to accomplish it.

A conscious designer, however, could fix this, because he or it could work
across that valley in design space, looking at intermediate designs which
were actually inferior to what we have, in the process of finally reaching
something superior.

It's entirely possible that we can't evolve faster brains for the same
reason: That there's no feasible evolutionary pathway that could be
followed, that we're hung up on a local maxima. I can think of several
reasons why our brains might not feasibly be able to clock faster. Look at
that blood supply! And the power consumption! It's flatly amazing just how
much of our resting metabolism is taking place in our brains. Maybe it's
just not feasible to supply more oxygen, and extract more heat. Maybe the
tendency to starve faster during famines balanced the advantages of thinking
faster. Maybe the metabolic machinery for keeping brain cells alive is in
competition with the machinery for doing the thinking, and a biological
neuron simply can't process faster and still handle the chores all cells
have to take care of to remain alive.

But that's no reason to believe that neurons based on some fundamentally
different operating principle couldn't ballance those constraints at a much
higher processing level. We'd never be able to evolve into having such
neurons, though. We might be able to design our way into them.

There's reason to believe that we're in evolutionary flux at the moment, in
just this respect. Famine is no longer a major cause of death in civilized
societies, so people aren't selected against just because they consume more
calories at rest. With C-sections, brain size isn't as constrained by the
need to avoid killing the mother during child birth, while still having a
narrow enough pelvis to walk.

I'm sure you've heard of the "Flynn effect", the fact that IQ scores have
been rising for several generations. This might be real evolution in action,
due to those changed circumstances. I think we might just be in the middle
of a slow-motion "Brainwave", and be destined to be substantially smarter in
the future even if we never do get around to genetically engineering
ourselves, or uploading ourselves into artificial neural nets. An exciting
thought, no? Of course, it could imply that we find ourselves hopelessly
outclassed if we're revived, and can't be upgraded...

Brett Bellmore

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