Re: [Phys-l] About the "why" and "how questins."

["Robert Cohen" <Robert.Cohen@po-box.esu.edu>]

William Robertson wrote:

> What seldom is 
> presented to the public is the fact that the Earth would be 
> warming at this point (according to ice core data) if humans 
> never existed.

Is that a fact?  Why?

> One could actually make a case that 
> the mechanism of Darwinian evolution, natural selection, is a 
> fact.  We have seen natural selection both in nature and in 
> the laboratory. It happens.

What did we observe?  Natural selection or evolution?  Both?  Neither?

> What is not a fact, but rather a 
> theory, is global evolution, the evolution of species via 
> natural selection throughout the Earth's history. We have a 
> fossil record (fact) and a mechanism (natural selection), but 
> all that does is make global evolution a very good theory, as 
> you say. So, scientists should present evolution as a very 
> good theory, not a fact.

So, global evolution is a theory, but natural selection is a fact?

I don't disagree with your contention that scientists need to be
careful.  However, I'd feel better about following your arguments if you
could provide a definition of a fact vs. a theory.  Also, definitions of
evolution vs. natural selection vs. global evolution would be nice.

----------------------------------------------------------
Robert A. Cohen, Department of Physics, East Stroudsburg University 
570.422.3428   rcohen@po-box.esu.edu    http://www.esu.edu/~bbq