If evelution is true, then.....

Dear Jim,
  Your confusion stems from the idea that evolution applies to things like
the formation of the solar system or the "lifespan" of the Sun.
The theory of evolution applies only to organisms that are living in the sense
of having genetic material that is passed on to descendants.  Even though
we refer to the "life" of the Sun, the Sun is not in fact a living organism.
  It has no genetic material nor does it produce offspring.  For evolutionary
processes to take place, the transmission of genes from parent to offspring is necessary.
  If anyone tries to tell you that evolution in the Darwinian sense of the word
can explain the formation of the solar system, the planets' orbits, or anything else
astronomical, they clearly do not understand what the theory of evolution is all about.
  To summarize: the theory of evolution, first formulated by Charles Darwin in the 19th
century, attempts to describe the characteristics of organisms living on the Earth.  In
Darwin's time that meant birds, fish, insects, and mammals.  The theory has
since been applied with great success to microscopic organisms such as bacteria.
All of these organisms have in common their use of DNA as a genetic code.  No living
organism is known that does not use DNA (or the closely related RNA) as the mechanism
by which genes are passed down to descendants.  Thus, the current scope of 
evolutionary theory is organisms that use DNA as their genetic material.  Strictly speaking, the
concept of evolution does not apply to anything in the observable universe which does not use
DNA in this manner.  So evolution is not the reason for the Earth's existence, in fact it
has absolutely nothing to do with the Earth's (or the Sun's) existence.

Hope this helps,

Joe Simpson
MD/PhD Student
 School of Medicine