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evolution

The Tree of Life is very big

http://www.zo.utexas.edu/faculty/antisense/tree.pdf

You’ll have to zoom in for quite a while before this PDF starts to make any sense to you.  Look in the upper left quadrant for “You Are Here.”

This is from the laboratory of Hills and Bull at the University of Texas.  I am led to believe that this is part of an attempt to construct the most massive and up to date representation of the tree of life around.  In scrolling around this circle (and unfortunately, getting this song stuck in my head) I was reminded of a few things that have given me pause.

  • In the paraphrased words of Richard Dawkins, there are a lot more ways to be dead than alive.  For every organism on the outside of this circle, there are thousands with names of their own that are extinct.  If the diversity of life on earth is staggering, the diversity of no-longer-life is Brobdingnagian.
  • This circle is a great way to illustrate the concept of “transitional organisms.”  If we were to draw a concentric circle at any point inside this one, it would represent a moment in time.  If we could transport ourselves to that moment, every animal and plant we saw would look exactly like a “fully formed species.”  Each one would be adapted to its surroundings.  Yet, if we move inward or outward for any geologic difference, we would no longer recognize what had earlier seemed to us to be clearly delineated species.  Instead, there would be a whole new set of “clearly defined” species.  Finally, if we were to draw another circle on the outside, it would represent the future.  The same process we can see on the inside would continue, and we would see new animals and plants that look just like fully formed species.  In short, life is transitional, and there is no such thing as a non-transitional organism.
  • It’s impossible to know how far the line for “Homo sapiens” will extend into the future.  What we do know for certain, however, is that one of two things will happen to it.  Either it will dead end, or it will change.  That’s a really hard thing for most of us humans to grasp.  We think of ourselves as being… well… HUMAN… as if there’s something magical about it.  However, if life on earth survives another five hundred million years (or a billion, or two billion), Homo sapiens will be a geological curiosity.  Perhaps our descendants will be smart enough to figure out that we are their ancestors.  Or, perhaps a drastic change in the environment will make it impossible for us to survive, and our line will end.   If we survive, maybe we will look very similar in half a billion years.  It’s worked for cockroaches and crocodiles.  But in the end, the simple math of natural selection will prevail.  We will not stay the same forever.
  • While this diagram obviously doesn’t include every single species in existence, it’s helpful for us to be able to see just how close we are to other animals we consider quite different.  Above Homo sapiens is Mus musculus.  That’s a house mouse, if you didn’t know.  Typhlonectes natans is a rubber eel.

For me, this kind of visual illustration of the staggering diversity and complexity of life is enough to make my head spin.  Yet, the basic process that drives the whole thing is simple enough that a grade school child can understand it.  From utter simplicity comes unimaginable complexity!  We know this concept even if we don’t acknowledge it.  The computer I’m typing today’s entry on is a complex machine, capable of retrieving information from virtually anywhere on the planet nearly instantaneously.  It is a marvel of function.  And yet…

At its core is a system of two numbers.  Everything reduces eventually to 1 or 0.  On or off.

Who says we need the supernatural to experience a sense of awe?!  The natural world is amazing enough, and has enough mysteries for my lifetime, and yours, and for all our collective children until humans are no more.

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Discussion

One thought on “The Tree of Life is very big

  1. The de-deification of culture (including the sciences) is our task for the next 100 years.

    If I recall correctly, Stephen Jay Gould estimated that on average a species lasts about 2 million years.

    Of course you could also be a member of a young species zapped by the next massive meteorite impact!

    As long as scientists and science writers insist upon using ‘machine’ and ‘mechanism’ in explanations of biology — they will continue to imply design.

    Of course living entities express our hard won abstract mechanical and geometrical principles (as molded by physical constraints) but there is no divine blueprint or artificer for any of them (including us).

    There are no machines in nature. Machines are designed. They serve our purposes.

    Living entities inherently serve no purposes.

    Only persons (a cultural construct) take on roles.

    the anti_supernaturalist

    Posted by anti_supernaturalist | October 24, 2009, 1:05 pm

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