General ---------Biology----------------------------------------------------- ------------------Online--------------------------------------------------------------------------------- Ch. 4 Carbon and the Molecular Diversity of Life

Carbon compounds are carbohydrates, proteins, fats and nucleic acids and fragments of these molecules.  To start our discussion of how organic molecules arise on earth, see if you can fill in the following blanks.

Energy from the ______ is used by plants, in a process called ________________, to produce _________.  Then plants rearrange these initial organic molecules to form _____________, _____________, ______________and _______________ (____&____).

Early scientists assumed that these organic molecules were produced only by living plants and animals.  If true, where did the first organic compounds come from?  This question essentially asks, where did the first life on earth come from?  Stanley Miller did some experiments in 1953 and demonstrated that basic organic molecules, the building blocks of life" could come about naturally.  Although no one has "created life in a test tube," his discovery fueled the debate between scientists who speculate that "life" lies outside the realm of science and ultimately must flow from a Creator and can't spring into being on its own and scientists who speculate that "life" will ultimately be understood by science and perhaps even created in a test tube.

The debate rages; is there something about those chemical reactions we call "life" that lies outside the realm of science, or is life ultimately understandable with the tools of science?

This debate extends ultimately to the origins of the universe; if the universe was created in the Big Bang, then who or what caused the Big Bang?

As science continues to push back the frontiers of human knowledge, will we ultimately understand every thing, or will there always be something science can't explain?

If the universe is ultimately explainable by science, then some day scientist will be able to make a mathematical model of life, the universe and everything.  This model then should be able to predict everything: will it rain tomorrow, which horse will win the Kentucky Derby, will you get married next year, will you make an A or a B in Biology. 

If the universe is explainable by science, then some say it must be "mechanistic," a big machine, completely explained by physical forces.  If that is true then we humans must also be machines. The mechanistic view is also called "deterministic," as it implies everything is predetermined.  If a human is simply a machine, can you hold a person responsible for their actions?  Does it make any sense to punish a machine?  If humans are totally determined, then does it make any sense to try and do well in this course?  Is the route you will drive the next time you leave your house predetermined, or do you have free will to drive any route you wish? 

Another view holds that life is not deterministic, but the result of a "vital spark" arising from a creator and giving life a spiritual component that lies outside the realm of matter and energy.  If the universe can contain "vitalistic" components, then perhaps your spirit (your thoughts, emotions and the conscious awareness you feel) is not simply a machine grinding its way to some destiny already determined by the mechanical laws of the universe.  Maybe humans do possess free will. 

The vitalism/determinism debate is profound, and it is the basis of modern political and social controversy.

This debate is an over simplification; modern science holds that mathematical models of the universe have a component of statistical probability in them.  These models reflect chaos, random events and a significant level of uncertainty.  One of the fundamental principles underlying modern physics and quantum mechanics is the "Heisenburg Uncertainty Principle." Perhaps human free will is a reflection of this uncertainty.

Assignment: Where do your beliefs fall along the vitalism-determinism spectrum?
Write you answer in one paragraph of three sentences, and print your name on the paper.  Do not turn the paper in; keep it with you to read to your classmates.

If you are interested in understanding how modern science views living protoplasm, you might enjoy reading "Life Itself," by Boyce Rensberger. 

Newton and Einstein's contribution to the vitalism determinism debate.

Summary:  Students should write summary statements below as bullet points.