But
the impression of such a force is so strong, so deep, so instinctual that, try
as we might, we cannot simply abandon it without at least wondering why it is
there, where it comes from, and what it tells us. Something
is there, of that there can be no question.
Intentionality. Complexity.
Design. Try to put aside your ordinary
impressions and perceptions of things, and seed your mind, germinate in your
mind, take root and push out of the soil and put forth leaves and vines in your
mind, the theme that to satisfy our curiosity we must look at the world from a
different perspective, the one that imagination unlocks. Very often, we find that when we look
closely, what we thought we were seeing fades away, yet is replaced by
something just as amazing – no, more so.
Let
us start with the simplest of things that could be called living. Consider the virus. Here is something both considerably smaller
and simpler than the smallest, simplest bacterium, all biologists would
agree. But on the most microscopic of scales,
that of individual atoms and molecules, even the simplest virus turns out to be
a machine of remarkable complexity. At
the very least it has to be able to recognize a host cell it can parasitize,
whether it is a cell in your body or a bacterium (in which case it is called a
bactaeriaphage), somehow figure out the molecular locks and other gizmos which
cells use to protect themselves from invasion, penetrate the defenses, then
usurp the molecular machinery the cell uses to replicate itself, perverting the
cell into a factory for producing many more copies of the virus, copies which
then have to figure out how to break out of the cell in order to repeat the
cycle on other cells or bacteria, all the while avoiding or distracting the
many other layers of defenses cells and bodies use to protect themselves from
such invasions.
Biologists
still debate whether viruses can be legitimately counted among the various
kingdoms and domains of life, but there is no doubt that their hosts, whether
bacteria or other single celled organisms or multicellular organisms, can be
classified in the great Tree of Life, from which all other living things, be
they plants, animals, fungi, or you, diverge from. And what dominates this tree, right down to the
most primitive beginnings we have yet been able to detect, is a level of
complexity that we simply do not encounter among the great many more things
than don’t belong on this tree, from rocks to stars to solar systems to
galaxies.
So
after all this, have we cornered our quarry?
We started with the at first sight idea that life possessed some special
quality or substance or essence, then realized that we could not find that
essence however hard we looked. But what
we did find was that living things, even the simplest of them, showed a level
of complex organization well beyond the most complex of non-living things.
Life
is special. I don’t want to lose sight of that. We are fully justified in our grand division
of matter into the non-living – things we explain only by the laws of physics
and chemistry at a simple level – and the living, all the things we must also
apply whatever biology has to teach us.
What I have been trying to show is that, whatever that specialness is,
it isn’t as obvious as it appears upon first sight. It is more subtle, involving a number of
characters and qualities, one of which is complexity and another the appearance
of design or purpose.
* * *
Again,
I say that life truly is special. It is
early May, and I have just come home from a walk through Pennypack Park, one of
the many lovely natural places which skirt the city where I live, Philadelphia,
one of several cities along the eastern
edge of North America. I would love one
day to walk on the moon or on the red soil of the planet Mars, but what I have
just experienced would be utterly lacking in those dead, albeit fascinating
places. In the spring in this part of
the world, as in many other parts of our planet, every sense is roused to life
by the call of the wild. Not only are
you surrounded by the verdant green of new buds and flowers and grasses, but also
by a cacophony of whistles, chirps, tweets, and other rhythmic sounds which reminds
you that you that new life is all about, some of it still rustling itself to
full wakefulness after winter but much of it already in the air and alit on the
many twigs and branches. And even without
vision and sound, you can still smell the musty beginnings of stirrings things,
the scents of enticing blossoms and irritating pollens, and you can still feel
the grass between your toes and the softness of young leaves on your skin as you
brush by the undergrowth.
Here
I have spoken of complexity and the appearance of purpose and meaning, and
perhaps that is exactly what our scientific mission into the heart and soul of
biology requires, but this is one place where, I have to submit, we will never
really capture the essence of what we are studying. Life is something that has to be experienced,
and only living things themselves have the capacity, as far as we know, to
experience anything. So, in a sense, our
quest to satisfy our curiosity begins with the admission that, at least for the
world of the living, we never can completely satisfy it.
Am I going to give up, then? No, because, as I have maintained up to this
point, curiosity combined with imagination and the scientific method can undo
any knot, unlock any riddle, however baffling and impervious it may seem. I have even suggested a starting place even,
this idea of complexity combined with apparent purposefulness, an idea I hope
to build upon and demonstrate just how powerful it is. I think we can agree that it is a good
starting place. Biological things, even
the simplest of them, are highly complex, we now see, and there does seem to be
something to this notion of being imbued with purpose, however that comes
about. If we can make some progress on
this front, then perhaps in the end we will satisfy our intellects after all,
as impossible as that seems looking at things from their beginnings.
