A few quick comments I should toss out:
1) There are alternative explanations to evolutionary theory, but they lack both the parsimony and the empirical evidence that provides support for evolution. In addition, many of these alternative explanations have not been subjected to peer review (proponents of Intelligent Design, for example, do not publish in any peer-reviewed scientific journals).
2) I do not believe the standard neo-Darwinian model of evolution actually claims to explain "how life began" or the "origin of life". It focuses moreso on gradual speciation mechanisms that began
after the emergence of single-celled organisms.
3) Strictly speaking, nothing can be absolutely
proven in science. This is why the scientific method allows for continual self-correction and genuine progress in our understanding of things (it rejects the concept of ultimate or absolute "truths"). However, evolutionary theory is widely
supported by the existing evidence.
4) It should be understood that the term
theory means a very different thing in science than it does to the average person. In this particular context, a
theory refers to a time-tested hypothesis that has amassed a large body of supporting evidence. In much the same way, cell theory (the proposition that all living organisms are composed of cells and that cells are created from other cells) is also "just a theory".
5) What some call "macroevolution"
has been demonstrated in laboratory environments. Specifically, I am referring mostly to certain species of bacterium, but there are other examples. Please go to
www.talkorigins.org for detailed explanations.
6) The question of how long significant evolutionary changes take is currently the subject of research and debate in the sciences today. Gould's "punctuated evolution" hypothesis (which posits that several forms of "macroevolution" took place over relatively short stretches of time) began looking into this stuff in the 1970's, and the current post-Darwinian explanations (which began in the 1980's) are providing us with some interesting research and data. Apparently, in some cases, "macroevolution" can take place within the course of single generation of organisms. See
A Discussion of Evolutionary Theory for more details.
7) As to the scientific validity of religion, that depends entirely on what you mean by both "science" and "religion" (read Wilber's
The Marriage of Sense and Soul: Integrating Science and Religion for an indepth discussion of this topic). I would assume you are referring specifically to the claims of Biblical mythology, which by and large have been refuted by empirical investigation.
Laterz. :asian: