The appendix, spare part?

[RationalBiker]

But...one could easily conclude that everything in this life does have/serve an undeniable/unavoidable purpose...if you, too, have recently found this as inherently obvious as I do, despite whatever doctrine you may prescribe to, perhaps it's time that you revisited those precepts"?"

I don't find that to be inherently obvious, nor do I prescribe to any particular Doctrine, unless it's the RationalBiker Doctrine of striving to observe reality from an objective point of view and coming to objective conclusions. I thnk those precepts are pretty solid.

[Maarten]

But...one could easily conclude that everything in this life does have/serve an undeniable/unavoidable purpose...if you, too, have recently found this as inherently obvious as I do, despite whatever doctrine you may prescribe to, perhaps it's time that you revisited those precepts"?"

By way of further explanation (to use your example), of the various components of our bodies that make up/contribute to the human hearts' functionality, do you see anyone of which we could do without yet still enjoy the same level of performance/continue living in it's absence? Then, if not, would that observation alone not intuit a specific purpose for each component in and of itself...or would it?

How does the fact that some attribute of an object that results in the object functioning imply that it was therefore designed like that? Just because something serves a particular end, does not mean that there is an intelligent driving force behind it. The thing is, that broken and useless objects do not help an organism survive (although they may not necessarily cause it to die off, either, if the drawback is very small). That means that there is no driving force present to propagate this particular attribute.

The reason you only see hearts with fully functioning parts is that all the hearts without fully functioning parts are rotting in the ground somewhere. That's the conceptual difficulty with evolution, because all the failed cases that support this theory are completely invisible to most people. You do not see all the random permutations that have ever existed in nature, because all but the most effective of these have gone extinct over the years.

And there is definitely a difference between some object's function furthering a specific end and that being its purpose. Purpose implies that something wanted it to do that, which isn't necessarily the case. Life has very specific demands, life has a very specific nature, and it's life itself that basically draws the "purpose" of the subcomponents it consists of towards furthering itself. Because that is the only way these attributes can remain in existence.

The fact that conscious intent is missing from these processes doesn't make them completely determined by chance, though. I think that is a false alternative that is nevertheless oftentimes held up by proponents of evolution. Because living organisms (or life itself, as an even more all-consuming concept) has a specific identity, only certain attributes are acceptable if this living being is to function and live. There is a reason for the way things are, but it is not to be sought in an Intelligent Designer, but in the nature of Life and what sort of relationship this particular attribute has to it.

[RationalBiker]

Please take any further debate about ID to the Debate sub-forum.

[Steve D'Ippolito]

Alright then, apologies all around as the intent of my post was not to convey an overall misunderstanding of the poster's (who is strangely absent from this rebuttal on his position) position inclusive of all of the members here, only my own.

Er.... You only posted your "rebuttal" (those so-called "scare quotes" are in the sense of so called) about fifteen hours ago (assuming the timezone matches my setting on the computer).

I have a full time job and I am building a house--I just spent several hours over there tonight. As a result I was unable to simply place myself at your disposal to answer "rebuttals" quickly enough to suit you.

Nonetheless you seem to be shilling for the Intelligent Designers. For that reason I do not care to continue this discussion with you, and that's just in addition to the fact that Rational Biker asked that that discussion be moved.

I *would* like to respond to Marc K. (where I think our sole real disagreement once we get past semantic issues is on the word optimal) but am not sure that I can do so without further aggravating Rational Biker.

[RationalBiker]

I *would* like to respond to Marc K. (where I think our sole real disagreement once we get past semantic issues is on the word optimal) but am not sure that I can do so without further aggravating Rational Biker.

I have no problem with the discussion per se, just not in this thread. If desired I'll gladly move all those related posts to their own thread in the appropriate sub-forum.

[Marc K.]

I have no problem with the discussion per se, just not in this thread. If desired I'll gladly move all those related posts to their own thread in the appropriate sub-forum.

I should think that the side discussion of "optimal" between Steve D'Ippolito and myself would fit nicely in this thread, it is a way of bringing philosophic issues into the discussion.

However, I have no wish to hijack your thread. If you find this side discussion detracts from your intended purpose then by all means split it off. Biosciences still seems like the proper Forum.

[RationalBiker]

In reviewing your exchanges (Mark and Steve), they are not discussing "Intelligent Design" so if you want to carry on here go ahead. It's the ID stuff that needs to be taken elsewhere. I can see that one can discuss a optimal/suboptimal physiology without bringing in the ID nonsense.

Edited October 16, 2007 by RationalBiker

[Steve D'Ippolito]

In reviewing your exchanges (Mark and Steve), they are not discussing "Intelligent Design" so if you want to carry on here go ahead. It's the ID stuff that needs to be taken elsewhere. I can see that one can discuss a optimal/suboptimal physiology without bringing in the ID nonsense.

I figured as much but wanted to be sure you agreed first.

OK Steve (may I call you Steve?) it is extremely important that we be very precise in our usage here because philosophic principles are involved.

I have noticed that whenever evolution is mentioned a common misconception occurs because of fallacious thinking. It is to think of evolution as having or setting a goal; which is an example of the fallacy of reification.

A very common hazard. None other than Richard Dawkins takes great pains to argue against it. Unfortunately it's very hard to avoid either making that mistake or SOUND like you are making that mistake through unfortunate choices of words. (He's also at pains to avoid equating it with random chance.)

Natural selection is a process that tends to take A) existing species, in their existing contexts (including the physical environment, the local predators, the local prey), and favor whatever mutations or even chance pairings of alleles, give that particular organism an advantage. It's not invariably going to work out this way--if some chance mutation results in the birth of SuperLeopard, well SuperLeopard could still be killed by a falling tree before he can breed. But over time, given enough mutations and recombinations due to sexual reproduction, you will see the population of some species become better and better at living--be it a plant species that becomes more insect resistant, leopards better able to bring down grazing animals, or grazing animals better able to escape those leopards. This is not a "goal," it's just the way things work out.

Most mutations are actually "bad", i.e., they result in an individual less able to deal with their environment than they would have been, had that mutation not occured. I put "bad" in quotes here because I am not implying a designer going "oh, shit, screwed that one up, I hate it when I do that," or even some sort of goal-seeking evolution doing so but rather, from the standpoint of the organism's survival, it is a negative factor. Just to be clear on that.

Similarly a "good" mutation would be one that helps the organism that has it, to survive. From here on out, I will dispense with the quotes.

What we have seen is that the individual changes tend to be very small ones. The good ones will tend to be favored, and the bad ones will tend not to be.

A critical point to understand is that any large change is almost certain to be bad. I'm going to have to illustrate by example here. Let's represent the genetic code of some organism by the following random character string "sa;lkuyh-391av;snk". This organism is doing a good job of surviving in its environment. It so happens that, had the creature had a slightly different code--changing the first semicolon to a colon--it would actually be even better at surviving. But a large change like changing it to "sa;gfdryt391av;snk" would lead to a totally random mess--if the organism even survived long enough to be born. And most random changes, like changing the dash to a plus sign, are small, and bad.

That is not to say that there isn't a possible large change that would be an improvement--but there are such a huge number of possible large changes and such a very small fraction of them would be beneficial, that the fraction is essentially 0, and basically any large random mutation will be bad.

So if some descendant of the organism happened to have that colon in the right place, it would be more likely to survive and have descendants that prosper. Other changes would conversely not be "favored" by circumstance. (The quotes are there because I recognize that word, read uncritically, tends to anthropomorphize the process.)

Alas, when I quote your post, the things you yourself are quoting disappear so what I am reading of the rest of your post is choppy. Let me try to repair this....

Now on to you. And please, I am not trying to pick on you or to nitpick the wording. Instead, I am trying to be precise so as not to leave the wrong impression with ourselves or anyone else who may read this.

As alluded to above: evolution doesn't make or cause changes. Individual organisms are stuck with their nature, given that nature they either survive or don't. They either succeed at achieving their values and live and reproduce or they don't and die.

I understand your intent. The trouble it is is so much FASTER to use a word that tends to anthropomorphize either a process or a machine, that people slip into that usage. In software we talk about code "talking" to other code and "wanting" certain things when everyone knows its inanimate and non-volitional.

What I was trying to say here was that the changes that would be favored (because they help the individual organism survive) will be small ones. A large change will almost certainly be bad, although IF someone were to look at the organism and be free to DESIGN a change that would make it absolutely unstoppable in the field, that change would be the best possible change AND would almost certainly not arise in the real world, where there is no designer. That large, hypothetical change is what I was thinking of when I said "the most sweeping." Not going to happen.

Now "best"--it may take a long time for that semicolon to become a colon. The mutation may actually not ever happen. But let's say that changing the first k in the string to a 4, 6, 8 or 9 is also an improvement--but not as much of one. That may happen first. It may also be the case that making both changes -- semicolon to a colon and k to one of those numbers--actually makes things worse than they were before.

(Imagine a protein chain that folds properly unless two amino acids are changed--but either one makes it work better.)

Now, what's the most likely thing to happen? Five possible individual changes--four of them a small improvment, five a larger improvement--but once you choose, you can't go back and pick the other because the combination is bad. Well, what's most likely to happen here is that some organism will have the 4/6/8/9 mutation first--and once that happens, and that propagates through the species, the other improvement, even though it would have been better, is now precluded because for it to happen you first have to change the number back to a k and the semicolon to a colon.

This is what I meant by stating that evolution may not make the best change. Through the process of evolution, improvments occur, but they are not necessarily the best possible improvements. And that is by the standard--strictly impersonal and non-volitional--of the organism's fitness to survive.

And this illustrates what I was trying to get at by referring to "wrong turns". It's not truly a disaster for the organisms that have that 4/6/8/9 mutation in their ancestry, but they could, conceivably have been better. And that is what I meant by saying things like suboptimal or less than optimal.

Our eye could be better. Some quirk of chance, back in our evolutionary history, caused our rods and cones to be oriented away from the pupil rather than toward it. For the octopus this did not happen. Vertebrate eyes work, obviously, since we have them and have been successful with them, but they would work even better if that oddball quirk had not happened. Obviously our eyes, in combination with our other attributes, have allowed vertebrate organisms to thrive.

Given that this happened, it turns out that mammals, given these eyes that were sub-optimal, underwent a minimum change that partially compensated--a reflective layer in the retina to bounce light back at the rods and cones. (This is why animals' eyes appear to glow in the dark--you are seeing reflected light.) Apparently we (apes with a very crucial rational faculty) are not a species that has a particularly good reflective layer but I think camera red-eye might be due to what we do have.

It might also be nice to have our skeleton on the outside ... but then we wouldn't be human. As I said before:

This is spot on and notice all of the qualifiers. "From a survival standpoint", meaning: "from the standpoint of the individual and its ability to survive". "[G]iven the starting conditions", meaning: "given our natures, which as an individual is set". It is observed that each species is ideally suited to exploit the environment into which the individuals are born. If the environment changes very quickly (in geologic terms) there may be enough variation within a species to allow for survival of the individuals with the best set of variables and those individuals will continue to exist. If the environment changes too quickly, every individual may die and the species will face extinction.

Sorry, I cannot agree with this. If the organism is "optimally suited" for its environment, that means it cannot be improved on. There is therefore no way for natural selection to select a slightly better genetic configuration, because there isn't one.

Because of this, I would take exception with the following as I understand it:

Any variation that allows an individual to survive better than the others is the correct change for that individual at that time; it wasn't the wrong turn at that time.

It is a favorable change, out of a large number of possible favorable changes, not necessarily the most favorable change. Not even necessarily the most favorable SMALL change--favorable large changes being vanishingly unlikely. And that change may (or may not) effectively preclude a change that would have been even better. (This is because that precluded change could NOW only happen by simultaneously undoing the change that did happen--much less likely to happen!)

And the phrase "could have been different" only applies to things that are open to human volition.

Nope, it can apply to random processes as well. To say otherwise would in effect assert that it was inevitable that intelligent life would arise on this planet in a species of ape, which is a primate, which is a mammal, which is a chordate--and could not possibly have arisen in, say, the archosaurs given enough time. But there was that awkward asteroid that wiped them out--another random event.

Of course the fact of the matter is that what actually happened, actually happened, and we have the privelege of dealing with it, good or bad.

But it is simply not the case that what actually happened is the best possible "optimal" thing that could have happened.