Definition of Life

[Ron Kagan]

>1  What is a good definition of Life? What are the criteria? Complexity?
>Self-organisation? Reproduction? Competitive reproduction/Evolution? When
>people argue over the Gaia hypothesis, (i.e. can the Earth be considered
a
>living organism) what are the criteria that apply?
>
>Any help would be gratefully received. (By email if possible)
>
>Thanks!
>
>----------------------------------
>Douglas Adams    <adamsd.cerf.net>
>----------------------------------
>

The best definition of life that I have ever come across was formulated
by the philosopher Ayn Rand:  "A process of self sustaining and self
generated action."

Apart from the definition, the chief descriptive criteria of living
entities can usually be found in a good biology text (they include
reproduction, movement, metabolism, response to stimuli, etc.).

Comments Welcome.


Ron Kagan
Graduate Student in Biochemistry, UCLA
rkagan at ewald.mbi.ucla.edu