Life as We Know It - and Its Evolution, Lead: Thomas Davis

2/11/2003

Summary by Gita George:

Life as We Know It and Its Evolution

Purpose: to present a quick layout of what we know/ think of our own existence to add a story about ourselves to cosmological evolution.
There are two sides to the story to focus on when we talk about time and evolution and life itself. The first part of the story is the physical universe. The second part of the story is connecting it to our own existence as observers.

* If we accept the Big Bang (BB) theory, then life as we know it now could not have existed before the instant of the BB.

Big Bang 44Origin of life 44evo4lu4tion4ourselves.

* If we do not accept the theory, then life could have always existed (or at least existed previous to BB).

Life = life as we know it NOW, we need a definition-(class discusses this subject later)

If we want to know about ourselves, than we can trace the story without necessarily talking about/ specifying where, exactly in the process, a transition from non-life to life occurred.

Here, Professor Möbius asked Professor Davis how? How can we trace life back without talking about the origin of life? To this Dr. Davis replied that it’s too hard to say “now we have it (life)… now we don’t”. (Möbius still looked puzzled as well as the rest of the class, but Davis said be patient, it’ll make sense as the discussion continues.)

Dr Davis continued by stating that we are OBSERVERS or EXPERIENCERS of Life. As observers, it is we who ask questions about the universe. He then posed the following philosophical/cosmological questions:

   • 1. What is there?
   • 2. How do things work?
   • 3. Why are they the way they are?
   • 4. What’s it all about? (Who cares?)
             Dealing with the final question4 if the universe was not being observed or experienced would it have meaning? (Dr. Davis thinks not)
   • 5. How did observers get here?
   • 6. Who are the observers/experiencers?4Do they have to be alive? Is life our key reason to observe?

SO…There’s a brief overview. Now…to talk about life
First, there’s the problem with terminology – i.e., the meaning of the term “life”. One way to address this question is to look at the ways in which we use the term:

How do we talk about life?

   • 1. Presence/ absence of life in a place
   • 2. Presence/ absence of being alive (the quality of things) – like plants vs. rocks
   • 3. Is the Earth alive?
            Is the Earth a living thing?
   • 4. Alive vs. Dead (to be dead you must have been alive)
           When is something dead?
           We can talk about legally. Legally dead, but its organs are still alive?!
           If we can bring it back from the dead was it dead? Degrees of death?
             ..these terms are ambiguous.
   • 5. When does life begin? [Human/animal] problems with abortion?
           When does status of “human being” begin?
           Biologically life doesn’t begin, it continues- sperm and eggs were alive to begin with.
   • 6. Life after death?
   • 7. Where does a living thing end and environment begin?
            Etc…Ambiguity arises again with the concept of life.

Is life even a useful scientific concept or does it just create problems if we can’t define it? This question has been addressed in an essay entitled “ “, by …

Dr. Davis and Shawn then discussed the example of a hermit crab. Is a hermit crab a living thing? If yes then is the shell alive? Dr. Davis said that the point he was trying to make is to ask: what is the boundary between a “thing” that we consider to be a living thing and its environment? There is life on earth. Where does this life end and the earth begin? The analogy would be between the “physical” earth and the hermit crab’s shell. The hermit crab is alive, and cannot live for long without a shell. Which is the living thing, the “naked” hermit crab or the hermit crab in its shell? To this Shawn asked Davis –what he thinks, does he think it’s alive? He answered: it’s not an entirely useful concept; it is problematic for certain purposes. Here Josh brought up the point that it depends on your definition of life - and we need a definition for this discussion to continue.
(the defining of the word becomes the focus of the class.)

The effort of defining the word takes up the conversation until it is realized that it is probably not definable in a way that everyone will agree on. Bill observed that life is an overused term, and a misused term. Davis agreed and said we can’t have a consistent definition- we must be very careful in using the word life. etc, much of class seems to agree.