Syd Lexia wrote:

we can't observe evolution in real-time.

Of course we can. When insects develop a resistance against pesticides what do you think that is? That's evolution. Observable in real-time. Scientists even have observed the origin of new species, both in the wild, as well as in the lab. Examples include speciation events in fruit flies, houseflies and lab rat worms.

It is evolution. Just do a quick google search for "evolution of pesticide resistence". You'll find plenty of scientific articles and books on the subject.

Good question. Yes, that has happened. Take a look at the talk.origins Speciation FAQ. Most of the papers mentioned there only report possitive assortative mating (i.e. flies only mating with flies of the same strain), but there are also some that report sterile offspring, for example Dobzhansky and Pavlovsky (1971):

Quote:

Dobzhansky and Pavlovsky (1971) reported a speciation event that occurred in a laboratory culture of Drosophila paulistorum sometime between 1958 and 1963. The culture was descended from a single inseminated female that was captured in the Llanos of Colombia. In 1958 this strain produced fertile hybrids when crossed with conspecifics of different strains from Orinocan. From 1963 onward crosses with Orinocan strains produced only sterile males. Initially no assortative mating or behavioral isolation was seen between the Llanos strain and the Orinocan strains. Later on Dobzhansky produced assortative mating (Dobzhansky 1972).

Dr. Jeebus wrote:

If I build up a resistance to certain types of poison, which is quite possible, have I evolved myself?

Populations evolve, not individuals. Yours would simply be a random mutation that gives you a survival advantage. If for some reason most humans were wiped out by a poison and only you and individuals with the same trait survived and produced offspring who are immune, then you could claim to have contributed to the evolution of the human species as a whole.

Cattivo wrote:

the sun's cycles could be a factor instead of man-made elements to any change in temperature

Solar irradiance is indeed a factor and every climate scientist will tell you so. However solar activity is not at work instead of man-made elements to produce the current warming. You can calculate the amount of solar forcing and it's not even close to the net anthropogenic forcings. That's what the current consensus is as summarized in IPCC WG1 SPM, page 4, which I already referred you to.

And that's not even mentioning that the claims of solar irradiance being the major contributor are contradicted by the fact that there are no changes in solar activity over the last thirty years of direct satellite observation (apart from the usual eleven year cycle) and that temperatures have kept rising during this time.

Cattivo wrote:

what scientists should we listen to? Shouldn't we take both types into account then?

If the other side makes up less than 0.3% of the peer-reviewed scientific literature then frankly, no. That's well within the normal margin of error for any scientific theory. Consensus does not require unanimity. If we waited for everyone to accept a theory before we move on, there'd never be any progress in science.

Cattivo wrote:

Nevertheless, I still see a distinction between theories and rules/facts

Yes, there is a difference. Theories explain things, facts just are. If you observe an apple falling down towards the earth's center that's a fact. Gravity is the theory that explains this fact. However gravity isn't "just a theory" as if somebody just made shit up while he was doing shots with his buddies. It's a well-established set of explanatory principles that has withstood empirical testing thousands of times. Same is true for evolution.

Cattivo wrote:

Past theories are proven wrong every generation.

That's a good thing to remember when dealing with anything in science, because it keeps us humble and our claims modest. But it's a bad ground for doubts about any specific theory. Such doubts have to come from specific problems that a theory has, rather than general observations about the nature of science.

Syd Lexia wrote:

Is gravity a theory or a law? Wikipedia seems to use the two terms interchangeably: http://en.wikipedia.org/wiki/Newton%27s_law_of_universal_gravitation#Problems_with_Newton.27s_theory

That's a tough one. I think Newton's take on gravity is better described as a law, because it describes a single phenomenon, but doesn't really explain it. The only explanatory element it has is that there's a gravitational field that is "caused" by mass. I guess you could call that Newton's theory, but I'm not really sure. Einstein's take on gravity however is definitely a theory, because it explains gravity in terms of space-time distortions.