If this is what you are really arguing for, then you have not being arguing for IC systems all along.
All parts of an IC system are necessary , thus, removing one of those parts destroys its function. In contrast, an olfactory system like ours has parts of varying importance : the olfactory receptor is necessary for olfaction, while parts like the nose are of lesser importance. That’s why you can reduce or minimize the number of parts of our olfactory system and still have the ability to smell, thus, disqualifying it as an IC system.
Is the functional remnant of a minimized olfactory system IC? No. It is what it is, minimized or reduced. That’s because its performance would be affected in some way (negatively or positively) by the removal of other less important parts. For example, removing your nose would badly affect your sense of smell, even though you would still able to smell. Its akin to lopping off one of your legs: you would still be able to move, but with greater difficulty. An IC system with well-matched, interacting parts shouldn’t experience such drop in function.
Well it evolved.
Minimized olfactory systems exist, but they are not IC, as I explained above.
That’s not true. Not all olfactory receptors are GPCRs, and so don’t need all of the three parts you listed.
which again is true for a minimal olfactory system. there is some minimum that cant be reduce anymore. if you agree with that (as you already agreed with the cellphone example i guess) then a minimal olfactory system cant evolve stepwise. this is the whole point.
we at least need 2-4 parts: one part for detecting odor molecule and one parts that can process it into smell (which probably contain few other parts). again, like a minimal cellphone or a PC fan
As ridiculous as @scd’s statements are in this discussion, we should remember that he is accurately representing Behe’s Irreducible complexity argument. He is just using less sophisticated, and therefore more transparent, language. Stripped of all the inessential, obfuscatory complications and digressions Behe introduces into his argument, @scd’s version lays bear just how utterly incoherent that argument is. So thanks for that, @scd!
That minimum will experience a decline in performance as other less important, but functional, parts are removed. An IC system consists of well-matched, interacting parts, which implies that its level of function shouldn’t be altered as other parts are removed, but this is not what we observe for an olfactory system like ours.
All this is true, but that minimized olfactory system is not IC, because it doesn’t function optimally in the absence of other parts.
Even if this minimized olfactory system was IC, it doesn’t follow that it couldn’t evolve. We have examples of IC systems that evolved in realtime, like the citrate-eating machinery under oxic conditions in Lenski’s LTEE.
ok. but why again you are going to human olfactory system? lets stay on topic. the topic is now about the minimal olfactory system.
what do you mean? if we will remove the OR for instance it will not be functional at all. the same is true if we will remove the part which process that signle from the OR. so we are talking about two different parts which require for a minimal olfactory function.
first, i dont think that the cit+ can be considered as a new function at all, since that enzyme was able to digest citrate before that mutation, and after that mutation.
I believe I have being discussing minimized olfactory systems (OSs) since. You can minimize or reduce (through surgery, for example) the components of the human (or any other organism’s) OS, but that affects its performance. For us, its a decline in performance. If our minimized OS was IC, that shouldn’t happen.
You missed the mark. I have stated, quite clearly, in previous comments that some parts of the OS (like an OR) are necessary and these necessary parts are what continue olfaction when other parts are excluded. However, olfaction in the absence of the other less vital parts is affected in some way. That shouldn’t be the case if those minimal, necessary parts were IC all along.
No. You are simply confused.
Whether you regard the citrate utility trait under oxic conditions as new or not (it is new by the way), it is IC and evolved right there in Lenski’s lab.
how exactly? dont you think that a minimal olfactory system need not only a OR but also a part which can process it for the organism? how this supposedly work? what is the first step?
an extra digit (Polydactyly) is also new and its also IC. do you think that extra digit show how an IC system can evolve?
so we do need at least few parts to evolve a minimal olfactory system. right? and if so, how it can evolve stepwise?
in this case some functions might be impossible without that extra digit (say for instance to push 6 bottons simultaneously). thus, its IC since these function will be lost. you can also think about this analogy: we can take a compass from a watch and put it in other place in that watch. now that watch has a new function (for instance we can watch that compass in the other side), but of course that we didnt realy added a new complex trait to that watch. we just move an exsiting part from one place to another.
right.
sure. but that isnt a complex IC. just a simple one. and this is only if we indeed consider it as a new IC system.
Not a minimal olfactory system, but a crude one. Olfaction involves detecting odorants with olfactory receptors expressed on olfactory neurons, and relaying information about that odorant to somewhere it will be processed and interpreted.
That’s quite easy. As I said before, olfaction involves sensing odors and interpreting information about them from those sensors. The sensors are receptors, the interpreter is a nervous system. Guess what? GPCRs are found in all lifeforms today including bacteria, indicating their ancient status, so the sensors evolved first. Nervous systems came along much later (only in metazoa [animals]), and got integrated with these sensors, generating the earliest olfactory systems.
I don’t know of buttons that are simultaneously pushed. I only know of buttons that are pushed sequentially. Stop throwing unreal examples to hold on to a dead idea.
Our palm and fingers (making up the hand), allow us to push (things like buttons), pull or hold objects. Fully developed six or five fingers allow us to do all three with great ease.
This in no way resembles what happened in the LTEE and it’s even crazy to compare the cit+ trait to moving parts around in a watch. You are truly ignorant.
But you don’t know that, nor how many parts that “minimum” system has. All you can say given current knowledge is that it might not constitute a functional olfactory system. But that doesn’t entail it would be functionless.
You are completely ignoring the possibility that each of the individual components in a GPCR can have other functions.
if they evolved first then what was their function? how a type of OR can be functional without any other part which can process its signle?
so this is still a new function that did not exist before: It is now easier to do certain things.
this claim is obscured by the observed reality: if we will remove some crucial parts of the system we will not get a different system but a non-functional one.
see above: an OR will always work with at least one other part. so we need at least 2-3 parts as starting point.
not the finger but that the change require to get that finger.
How do you compare “complexity” of IC? Is there an objective, quantifiable measure of it?
Are you arguing that sufficiently complex IC cannot evolve (let’s call this “irreducible irreducible complexity” or something like that), while simpler than this complexity limit of IC they can evolve? (let’s call this “reducible irreducible complexity”.)
if you asking me where is the limit, i will say that this depend on the number of mutations which require to evolve it. if the number of mutations i too high compare with the time scale, than i will claim that its unlikely that such a system evolved. so this depend on the specific situation.
For the first question, the answer is whatever function they were serving prior to being recruited into the olfactory system.
Your second question doesn’t make any sense. An OR is a protein and it changes conformation upon interacting with some other molecules. During this conformational change, binding sites for other proteins could get exposed, allowing for the evolution of protein assemblies or interactive networks. Thus, the OR could have been functional or nonfunctional prior to being incorporated into the olfactory system.
Its not a new function, because you can still push, pull, or hold objects with one, two, three, four, five or six fingers. With five or six fully formed fingers, its a lot easier to perform those functions.
