Matthew144

No, I just think that those advances have shown even the most "simple" of life is irreducibly complex, and so glossing over it begs too much of the question. In other words, I would very much like to discuss it.

faded_Glory

I have to disagree. DD's analogy is meant to explain the effects of a selection pressure. The fact that in this case the selection pressure is introduced by an intelligent agent does not detract from the validity of the argument. It matters not by what means the selection pressure is introduced - its mere presence is sufficient to change a random process into a directed one. No specification is necessary to introduce complexity; the fact that specification is present in the example serves only to make the point in an entertaining manner.

fG

[ December 05, 2002: Message edited by: faded_Glory ]</p>

Hawkingfan

Why does the word "random" scare everyone (even atheists)? Would you not say that life began from a chance combination of atoms? I believe the early organisms (called macromolecules) were formed from chance combinations of atoms. This was random. But it does not scare me because I know it happened as a product of quantum mechanics. In quantam mechanics, randomness is not a big deal because anything that is not forbidden by quantum theory can and will eventually happen. It's simply following a golden rule of quantum mechanics called the Sum Over Histories. That theory is best shown with the movements of electrons around the nucleus of an atom. By the Uncertainty Principal, a scientist cannot measure a particle's (in this case an electron) exact position and velocity at the same time. He can only measure one, but be very unsure of the other. But the scientist can predict the probability of where the electron is most likely to go if he takes into account where the electron has been (the sum over it's histories). In fact, quantum mechanics does not predict anything at all as far as accuracy is concerned. It is simply a tool to determine how likely any possible outcomes are. But remember, EVERY POSSIBLE history WILL occur eventually (the electron will have travelled every possible path around the nucleus), that's right--BY CHANCE--but then is "chance" that big of deal? No.
So keeping that in mind--For millions of years, there were combinations of atoms that had no consequences whatsoever to life. But they recombined and recombined by chance (the sum over histories) until one had formed the macromolecule. The macromolecule reproduced but there were ERRORS in the reproduction (because of the Uncertainty Principle and from the thermal motion of atoms). Some of the errors proved to be beneficial to the molecule's environment (in this case it would have been a macromolecule that was able to combine with the atmosphere, taking the sulfur oxide, carbon dioxide, nitrogen, etc. out of that first atmosphere--a very poisonous atmosphere, at that, where man could not have survived and which the earth had received from the gases from the rocks and inside the earth--and then that macromolecule expelled a waste (in this case oxygen--which would later transform this way for millions of years to form our current atmosphere)).
This was the first evolutionary process, because the beneficial errors were passed on in the reproductions.

pz

Please do. Do you have something in mind? Please be specific. I'm doing my Karnak the Magnificent routing right now, and I can probably guess what molecular system you want to bring up.

I should mention, though, that the term "irreducibly complex" is not a good one to use. It immediately labels you as someone who doesn't know much about molecular biology, but who adopts facile jargon readily.

theyeti

Sure you don't mean Kimura? Ohno's contribution was, IIRC, that he was first to propose gene duplication as a major source of evolutionary innovation.

theyeti

pz

Yes, my mistake.

Doubting Didymus

No, I do not need to tiptoe around my analogies just to avoid accidentally feeding an IDist. They are responsible for their own misconceptions and I should not have to keep them in the forefront of my mind at all times. The analogy was not meant to illustrate undesigned biological history, but randomness filtered by selection.

Doubting Didymus

I have conceded nothing. There is practically nothing in my entire post that was not known and accepted by biologists a century ago. Not since the days of spontaneous generation has anyone thought life arose randomly. That was nearly 200 years ago now.

I certainly don't think so. The junkyard agrument is simply that complex things are not formed by chance. Do you then concede that natural selection can bring about a man from a bacterial beginning? I didn't think so, so if you will allow abiogenesis to sit in the background for just a moment, let us first establish the ordinary claims of common descent.

You really want to talk about abiogenesis, don't you? Well although I would much prefer to first establish that bacteria are capable of evolving into mammals, I suppose we can deal with this issue first. Don't expect to be able to continue changing the topic, however.

Abiogenesis, then. First: it is important to realise that the first abiogenesis 'thing' was not a bacterial cell. It was a simple, probably non 'living' replicating thing. The cairns-smith theories suggests that something as common as clay crystals may have the properties needed to kick start evolution. Other theories reqire the possibility of chance formation of small RNA strings capable of replicating themselves. The main reason I wanted to avoid this topic was that there is very little concensus on what the first replicator even was, so making guesses about its probability is absolutely impossible. You can not apply the junkyard argument if we don't yet know what the whirlwind has to achieve. Maybe RNA is too complicated? So what if we really are looking at clay crystals? Is a lump of dirt too complicated to form in a junkyard?

So many questions, so little direction. Would you like to clarify your argument against abiogenesis a little for me?

Shadowy Man

DD:

I didn't say the analogy was inaccurate, just weak. Yes, you don't need to tiptoe, but I've seen this analogy pulled out to defend evolution against IDists, recently even in an article in Scientific American. When used for that purpose, it won't hold a lot of water.

I do understand your point about randomness filtered by selection, but is there no other analogy that is just as good and perhaps more accurate as to the process?

tronvillain

*shrugs*

A computer randomly generates a thousand texts and shows them to a person who only likes to read the complete works of Shakespeare and keeps the hundred texts top rated texts. It then generates another thousand texts by randomly introducing errors into ten copies into each of the hundred top rated texts, shows those to the peson who only likes to read the complete works of Shakespeare, and keeps the hundred most liked texts. It repeats this process until the ratings remain constant for a certain amount of time. Did you end up with the complete works of Shakespeare? Maybe. On the other hand you may simply have gotten somewhere along the way, where the path that lead to Shakespeare required a significant decrease in rating.

Better?