Simply by looking at all the facts (observed instances of evolution), using those facts to test predictions made by various theories and settling on the most solid of the theories - in this case the theory of evolution.
All these arguments are pointless because of a fundamental misunderstanding by those who think that evolution is 'just a theory' (emphasis on the 'just'). If something is a scientific theory and it's been around for anywhere near as long as the theory of evolution has (and is still seen as the favourable theory), then we can be pretty damn sure of it's validity.
A competing theory, such as Intelligent design, can be proposed (only it's not a theory) but it's no better than the theory of evolution - as far as theories go - because it makes no predictions whatsoever that we can test using physical instruments. We simply cannot observe an "intelligent designer" (one god in particular), or any instances of "intelligence" in our world - as it's an abstraction invented by humans which cannot be measured in our environemnt since it is defined in terms which are outside our physical environment.
Thus, since it is untestable, it is not a theory at all.
Slashdot Mirror
You mean DooVDe?
Simply by looking at all the facts (observed instances of evolution), using those facts to test predictions made by various theories and settling on the most solid of the theories - in this case the theory of evolution. All these arguments are pointless because of a fundamental misunderstanding by those who think that evolution is 'just a theory' (emphasis on the 'just'). If something is a scientific theory and it's been around for anywhere near as long as the theory of evolution has (and is still seen as the favourable theory), then we can be pretty damn sure of it's validity. A competing theory, such as Intelligent design, can be proposed (only it's not a theory) but it's no better than the theory of evolution - as far as theories go - because it makes no predictions whatsoever that we can test using physical instruments. We simply cannot observe an "intelligent designer" (one god in particular), or any instances of "intelligence" in our world - as it's an abstraction invented by humans which cannot be measured in our environemnt since it is defined in terms which are outside our physical environment. Thus, since it is untestable, it is not a theory at all.