miss_liz said:
Ok, this is sorta off topic, but....what is the difference between a scientific law and a scientific theory?
Okay, its nice to see some one ask this question if they do not understand. A Scientific Law is an observed fact, something that we always see happen given certain circumstances. The Law of Gravity for example tells us that objects fall to the ground unless lift and thrust are applied.
A scientific theory is the explanation of WHY we see what we see. In this way the theory of gravity tries to explain what causes objects to fall to the ground if lift and thrust are not applied.
Similarly the Law of evolution shows that allele frequencies change in a population over generations, the theory of evolution explains why and what effects this has.
miss_liz said:
That's one reason I have a problem with evolution...evidence keeps on popping up that requires the theory of evolution be 'mended'.
No, evidence does not keep popping up that require the theory be Mended. It occasionally pops up that requires the details be amended. To understand this rather confusing distinction you have to understand how scientific theories work, so bear with me and I will try to explain it without being overly verbose.
Scientific theories are actually bundles of several hypothesis, something is not a theory unless their is evidence to support it. However, a theory is effectively composed of two important parts, The Core assumptions and the Peripheral Hypothesis. The core assumption is that the law which we have observed and are attempting to explain is correct. The peripheral hypothesis are the explanations of how it all works. There will only be one core assumption but their can be thousands of peripheral hypothesis in any given theory.
If a peripheral hypothesis is falsified this does not mean the theory is wrong, it means some of the details are inaccurate and we need to go back and look at them again. To use the court case analogy again, if a murderer was on trial the prosecutions theory has the core assumption (that he did it) and several peripheral hypothesis explaining the how, when and where. Of the defence can prove he did not kill the victim at 9.35 because she died at 10.01 this does not prove the killers innocence (ie falsify the core assumption) it falsifies a peripheral hypothesis and the prosecution need to go back and find out what small detail they got wrong.
Same thing in science. if a core assumption is falsified the theory is wrong and we abandon it for a new theory (this is called a Paradigm shift). If a peripheral hypothesis is falsified we know we have a detail wrong and we need to go and find out what it is and how wrong it is, and why.
All scientific theories have peripheral assumptions corrected from time to time, evolution is no different to any other (including gravity).
So far we have never seen anything that comes close to falsifying the theory of evolution, quite the reverse all the new evidence we find supports the core assumption. From time to time we find something that tells us that a peripheral hypothesis needs correcting.
In effect it was Colonel mustard in the library, its just that we now know he used a lead pipe and not the candle stick.
Ghost