Evolution

• It is easily possible to breed horses for speed, fruit trees for fruit flavour and dogs for waggy tails and laziness.
  
• (Need more info on this) There are two species of gull that collectively encircle the globe with a ring of nesting sites. If you follow the ring around, you find that every gull can mate with its nearby neighbours, but gulls from opposite sides of the globe can't mate. One species has split seamlessly into two.
  

Myth Debunking

Mmmm, why "presumably"? Would you presume there are good reasons for not accepting the hypothesis of, say, general reliativity? There may be good reasons for not accepting it...there may not be...however, until someone puts forward these good reasons, I don't see why anyone should presume they exist. -- Xarak

Ignoring the accept existence of hypothesis / accept the truth of the hypothesis grammar thing..  If you accept evolution to be true then you have to accept that there are good reasons to doubt it.

That statement is so wrong in so many "have you stopped beating your wife?" ways.. ;) I am impressed. - MoonShadow

Since those who doubt it are able to breed, there must be some evolutionary advantage to it :)  Since the converse is not true (those who do not accept evolution do not have such a built in requirement to doubt that they are right) we can say that evolution disproves itself.  Which with a bit of handwaving becomes a proof by contradiction.  Ammo for the anti-apes!  --Vitenka

I used the word 'presumably' because at the time I couldn't think of any objections that actually had the capacity to disprove the evolutionary hypotheses, although I suspect that there may be a few. A weak example would be: civilisation screws evolution over, and yet we are developing the capacity to prevent genetic defects, therefore evolution is not all-encompassing, and we don't know precisely under what conditions it operates. So how can we accept it?

Fair enough, but I still don't see why you suspect these argments exist, even though you can't think of any. -- Xarak

Eh?  I gave such an argument above!  Lots of idi^H^H^Hpeople disbelieve evolution, and they have their reasons.  --Vitenka

The counterargument is of course that a similar situation exists with fluid dynamics, and yet we generally accept the Navier-Stokes equations as accurate. If anyone can think of any better arguments it would be great - hard to have a discussion without dissent or at least the potential thereof.

Incidentally, there are many reasons to doubt the theory of relativity - for a start, it doesn't work with quantum dynamics. Quantum dynamics is known to be a decent model under some circumstances, so it follows that general relativity is not general. If you're a Reductionist then by definition you must believe that there is a better theory lurking out there. - CorkScrew

I believe in classical dynamics for describing things on the metre length scale under certain conditions. I am quite capable of doing this even while using QM for describing radiation and electrons and SR for describing fast-moving macroscale objects (incidentally, the postulate of relativity - the laws of physics are the same no matter what frame they are applied in - is quite compatible with quantum mechanics IIRC). Any theory has limits on where it applies - CompareAndContrast? 'theorem'. --Requiem

However, Reductionists believe that there is a theorem for which the area of applicability is the entire universe, and for which all our theories are approximations thereof. General Relativity is a good approximation at certain scales, but it doesn't work at all scales hence cannot be the ultimate theory. Here's hoping we find the damn thing someday - my betting is that this AssemblyLanguage of the universe is out there somewhere, buried underneath the C++es and Pythons of the physical sciences. - CorkScrew

Vitenka's premises are incorrect. When we accept a scientific theory it doesn't mean we accept it as absolute immutable truth - that would be faith, not science; nor do we generally discard theories completely and start over from scratch when presented with facts that do not fit the theory - that would be stupid; instead, theories are adjusted or superseded as necessary. See [this FAQ], for instance. It is therefore somewhat irresponsible to say things like "If you accept evolution to be true then you have to accept that there are good reasons to doubt it", because they do not actually mean what it sounds like they mean. Let's take it apart, blow by blow.

• "If you accept evolution to be true" - what precisely does that mean you accept? "Natural selection is possible", "Natural selection has actually happened at some point", "All the species we currently see are the results of natural selection", "The theory of evolution - i.e. the reconstructed history of what species had what ancestors, etc. - is the best explanation we currently have for things we observe", "The theory of evolution is absolutely true in its entirety" - they are all very different statements.
  
• "then you have to accept that there are good reasons to doubt it" - well, check out how that applies to the statements above. There's no particularly good reason to doubt natural selection, as far as I am aware. Reasons to doubt parts of evolution theory are found all the time, but the result is not usually its complete dismissal - merely a reshaping to accommodate new facts, until it is once more the best available theory. This is brief and not particularly rigorous; check out the FAQ linked above for more detail on how scientific theories work.
  

• What use is half an eye?
  

• This is dumb. You can't change one species into another.
  

• That's pathetic, they still look exactly the same. It's not really evolution.
  

You might find that's two extra, four in total (although ICBW) :) Fruitflies are members of the Diptera - two-winged flies. Four wings is the basal condition, so it's not too surprising that they can revert. There was an interesting article in, um, Nature about the evolution of pelvic spines in sticklebacks. Hang on, will find a link - SunKitten

Article [here], interesting (and short) review [here]. You might need to be inside the university/have a subscription to Nature to view these - sorry - SunKitten

• But they're still flies dammit. All this "evolution" is on a titchy scale - I don't see how it can be scaled up to, for example, turn otter-type things into whales. [This is the current theory for the origin of the whale]
  

• Fossils aren't real, they're creations of Satan to tempt archaeologists [yes, I have heard this advanced as an explanation]