I can’t vouch for that one in particular, but it’s very much in line with what some theists say about evolution, yes—and I’m not even talking about the self-selected idiots on Youtube; I’m referring to things I heard while working at a Roman Catholic nursing home.
Meanwhile evolution advocates sometimes ask “How do you explain nerves going totally the wrong way out of the retina?” This leads to the age old philosophical question: “Can God create a keg of beer so large that even he can get wasted?”
Interestingly enough, a friend suggested that the backwards retina thing actually makes sense. The argument goes something like this:
You don’t actually need an exact photo. You need to be able to quickly spot the thing you’re hunting, or the threat that may be coming after you, etc… Attached to the retina is a computational layer that preprocesses images (edge detection, various other bits of compression) before sending it along the optic nerve. If you sent the pure raw data, that would mean more data that needs to be sent per “image”, so more effective latency.
So the computational layer is important. Now, apparently the actual sensor cells are rather more energetically expensive than the computational layer. If you put the actual image collector in front of the computational layer, then you’d have to have a bunch more blood vessels punching through the computational layer to feed the sensor layer. That is going to leave less computational power available for compressing/preprocessing it. So you’re going to have to send more or the raw data to the brain and then wait around for it to process/react to it.
So now this leaves us with putting the computational layer in front of the sensor layer. But, once we have that, since the computational layer has to output to the optic nerve, well, it’s pretty much got to punch through somewhere. If it simply went around, the path would be longer, so there’d be higher latency, and that would be bad. Would leave you less time to react when that tiger is coming for you.
I don’t really have any references for this, it’s just something that came out a conversation with this friend, but it does seem plausible to me.
(He’s not a creationist, incidentally. The conversation was effectively an argument about whether intelligence is smarter than evolution, I was noting the backwards retina as an example of some of evolution’s stupidity/inability to “look-ahead”. He argued that actually, once one starts to look at the actual properties a vision system needs to fulfill from an engineering perspective and look at how that relates to energy flow and data latency and so on, the “backwards retina” actually might be the right way to do things after all.)
So then it is the octopus eye that is wrong, and the vertebrate eye that is right.
In any case, that the facts are (partially) explained by common descent, but not by special creation of each “kind”, makes the nature of eyes within the animal kingdom evidence for evolution rather than creation.
Sure. I was just saying that maybe the backwards retina thing might not be the best example of evolution being stupid since that particular design may not be that bad,
As far as octopuses and such, how do their eyes compare to our eyes? how quickly can they react to stuff, etc etc?
(If I’m totally wrong on what I said earlier, lemme know. I mean, it’s quite possible that the friend in question was basically totally BSing me. I hadn’t researched the subject myself in all that much detail, so… However, his argument did seem sufficiently plausible to me that at least it doesn’t seem completely nuts.)
The thing is, he was claiming that we sort of figured this out in the process of trying to design artificial vision systems. ie, it wasn’t so much a “here’s a contrived after the fact explanation” as much as “later on, when we tried to figure out what sorts of design criteria, etc etc would be involved in vision systems, suddenly this made a bit more sense.”
Again, I have no references on this, but it does seem plausible.
And as it usually is with amateur engineers, one can persuasively argue that almost any existent design is inferior to a better hypothetical design.
Your saying is quotable, but it holds no weight against Psy-kosh’s point: an evolutionary adaptation that looks maladaptive to us is more likely caused by our current technical ignorance than actual maladaption.
Do you include professional biologists into the ignorant group? If so, are people justified to call any feature maladaptive? If not, why speak about adaptations whatsoever, when our ability to judge their true benefit is only an illusion caused by our technological ignorance?
Apriori, true maladaptions are rare. Evolution does not proceed by starting with hypothetical perfect beings and then slowly accumulating maladaptions.
So really, almost every feature is an adaptation by default. A maladaptive feature would have to actually harm fitness. There are certainly some cases of this you could show by engineering in a lab, but the retina is not such a case.
In the retina’s case, what we are really discussing is whether the backwards retina is a suboptimal design. But to prove that, you have to prove the existence of a more optimal design. Biologists haven’t done that.
A better route towards that would have started with comparing the mammalian/primate eye with an alternate ‘design’ - such as the cephalopod eye.
The substance of your statement basically amounted to an empty ad hominem against amateur theorists.
The substance of your statement basically amounted to an empty ad hominem against amateur theorists.
It was rather tongue-in-cheek than ad hominem, and intentionally so. But empty? To make up a wrong explanation which could sound convincingly to amateurs is quite easy in any science, evolution theory included. It is already acknowledged here in case of evolutionary psychology, but the arguments are valid generally for evolution.
In the retina’s case, what we are really discussing is whether the backwards retina is a suboptimal design. But to prove that, you have to prove the existence of a more optimal design. Biologists haven’t done that.
First, I have made no statement about optimality of retina, and I don’t disagree that the question may be more complicated than it seems on the first sight. In fact, it was basically my original point.
Second, all designs are almost certainly suboptimal. Optimal means there is no place for improvement, and the prior probability that evolution produce such solutions is quite low. It is also not so hard to see why humans can sometimes notice suboptimality in evolved adaptations: evolution works only by small alterations and can be easily trapped in local optimum, overlooking a better optimum elsewhere in the design space. That’s why I was puzzled when you have written
an evolutionary adaptation that looks maladaptive to us is more likely caused by our current technical ignorance than actual maladaption
I interpret it as “we can never confidently say that any adaptation is suboptimal”, or even “everything in nature is by default optimal, unless proven otherwise”, which is a really strong statement. Do you maintain that the perceived maladaptivity of human appendix is also probably an illusion created by our insufficient knowledge of bowel engineering?
To make up a wrong explanation which could sound convincingly to amateurs is quite easy in any science, evolution theory included
Yes, and I was pointing out that this applies equally to biologists acting as amateur engineers.
In the retina’s case, what we are really discussing is whether the backwards retina is a suboptimal design. But to prove that, you have to prove the existence of a more optimal design. Biologists haven’t done that.
First, I have made no statement about optimality of retina, and I don’t disagree that the question may be more complicated than it seems on the first sight. In fact, it was basically my original point.
Your statement seemed to me to be a blanket substance-less dismissal of the original discussion on why the retina’s design may not be as suboptimal as it appears to amateur engineers.
Second, all designs are almost certainly suboptimal. Optimal means there is no place for improvement, and the prior probability that evolution produce such solutions is quite low.
I doubt your certainty. Optimality is well understood and well defined in math and comptuer science, and evolutionary algorithms can easily produce optimal solutions for well defined problems given sufficient time & space. Optimality in biology is necessarily a fuzzy concept—the fitness function is quite complex.
Nonetheless, parallel evolution gives us an idea of how evolution can reliably produce designs that roughly fill or populate optimums in the fitness landscape. The exact designs are never exactly the same, but this is probably more a result of the fuziness of the optimum region in the different but similar fitness landscapes than a failure of evolution.
It is also not so hard to see why humans can sometimes notice suboptimality in evolved adaptations: evolution works only by small alterations and can be easily trapped in local optimum, overlooking a better optimum elsewhere in the design space.
I think this is a mischaracterization of evolutionary algorithms—they are actually extremely robust against getting stuck in local optimums. This is in fact their main claim to fame, their advantage vs simpler search approaches.
an evolutionary adaptation that looks maladaptive to us is more likely caused by our current technical ignorance than actual maladaption
I interpret it as “we can never confidently say that any adaptation is suboptimal”,
or even “everything in nature is by default optimal, unless proven otherwise”, which is a really strong statement.
You somewhat overinterpret, and also remember that the quote is my summarization of someone else’s point. Nonetheless, I stand by the general form of the statement.
It is extremely difficult to say that a particular adaptation is suboptimal unless you can actually prove it by improving the ‘design’ through genetic engineering.
Given what we currently know, it is wise to have priors such that by default one assumes that perceived suboptimal designs in organisms are more likely a result of our own ignorance.
Do you maintain that the perceived maladaptivity of human appendix is also probably an illusion created by our insufficient knowledge of bowel engineering?
wnoise answers this for me below, and shows the validity of the prior I advocate
Do you maintain that the perceived maladaptivity of human appendix is also probably an illusion created by our insufficient knowledge of bowel engineering?
I agree with your basic point, but this might not have been the best example. We’re now fairly sure that the appendix is useful for providing a reservoir that keeps friendly gut bacteria around even when diarrhea flushes out the rest of the GI tract.
Overall, probably now maladaptive for the average first world citizen. For the average third world citizen, or in the environment of evolutionary adaptation, that’s less clear.
I don’t know enough about the computational details to comment on those aspects but will note that some sea creatures don’t have the reversed retina. So it does seem like it really is in humans an artifact of how we evolved.
Oh, yes. It is asked pretty regularly in the forums that deal with such things. Places like talk.origins.
Creationists have a world-view which places God-the-creator at the base of all explanations regarding the nature of reality. Remove Him and much that was explained is no longer explained. Asking an “evolutionist” to explain the natural existence of the eye—a mechanism of considerable intricacy and sophistication—is perfectly reasonable in this context, particularly for someone who doesn’t understand natural selection at all. Which most people, theist or atheist, don’t understand.
Even theists who understand natural selection, people like Behe or Dembski, can find evolutionary explanation unconvincing when they change the question from “How did the eye become so nearly perfect?” to something like “How did eyes get started, anyhow?”. To be fair, they find the explanations unconvincing because the standard explanations really are unconvincing and they are unwilling to accept a promissory note that better explanations will be forthcoming in time.
There is some truth to the claim that even atheists currently take some things “on faith”. The naturalistic origin of life, for example.
Hold on, the naturalistic origin of life is pretty plausible based on current understanding (Miller-Urey showed amino acid development would be very plausible, and from there there are a number of AIUI chemically sound models for those building blocks naturally forming self-replicating organisms or pseudo-organisms).
Are you genuinely arguing that its probability is so low that it would be less productive to investigate naturalistic abiogenesis mechanisms than it would be to look for new hypotheses? Or, alternately, do you have a more specific idea of what minimum level of probability it takes for a hypothesis be “plausible” rather than “being taken on faith”?
There is some truth to the claim that even atheists currently take some things “on faith”. The naturalistic origin of life, for example.
Hold on, the naturalistic origin of life is pretty plausible based on current understanding.
And that claim by you is based on … what exactly? Experiments you have performed? Books you have read explaining the theory to your satisfaction with no obvious hand waving? Books like the ones we all have read describing Darwin’s theory of evolution through natural selection? Or maybe you have encountered a section in a library filled with technical material beyond your comprehension, but which you are pretty sure you could comprehend with enough effort? For me, something in this category would be stereo amplifiers—I’ve seen the books so I know there is nothing supernatural involved, though I can’t explain it myself.
From what you write below, I’m guessing your background puts you at roughly this level regarding abiogenesis. Except, the difference is that there is no library section filled with technical material explaining how life originated from non-life. So, I think you are going on faith.
(Miller-Urey showed amino acid development would be very plausible, and from there there are a number of AIUI chemically sound models for those building blocks naturally forming self-replicating organisms or pseudo-organisms).
No there aren’t. There is not a single plausible theory in existence right now claiming that life originates from amino acids arising from a Miller-Urey type of process. There are no chemically sound models for creating life from Miller-Urey building blocks.
There are some models which have life starting with RNA, and some which have life starting with lipids, or iron-sulfide minerals or even (pace Tim) starting with clay. But you didn’t mention those more recent and plausible theories. Instead you went on faith.
Are you genuinely arguing that its probability is so low that it would be less productive to investigate naturalistic abiogenesis mechanisms than it would be to look for new hypotheses?
No. Not at all. I don’t have a clue as to what it would even mean to look for, let alone investigate a non-naturalistic hypothesis.
What I am saying is this: Suppose I have before me a theist who claims that a Deity must have been the cause of the Big Bang. “Something from nothing” and all that. Suppose further that my own version of atheism is so completely non-evangelical and my knowledge of cosmology so weak that I say to him, “Could be! I don’t believe that a Deity was involved, but I don’t have any evidence to rule it out.”
So that is the supposition. Next, suppose he says “Furthermore, I think the Deity must have been involved in the origin of life, back 3+ billion years ago. From what I know of chemistry and biochemistry, that could not have been spontaneous.” I would tell him that I too know quite a bit about chemistry and biochemistry, and that there are many, many clues indicating that life based on RNA probably existed before modern life based on DNA and amino acids and proteins. There is strong evidence that life in its current form came from something more primitive.
Now, suppose he says “Yes, I understand all that evidence. But you still have no theory to explain how life based on RNA might have started. All you have is handwaving. My belief, since I already believe in a Creator-Deity for the Big Bang, is that a Creator-Deity was also involved in the origin of the RNA World.” If he said that, then I would answer, “Ok, you can believe that, but since I don’t already believe in a Creator Deity, I would prefer to believe that the first living organism on earth arose by some unknown natural process. In fact, I have some ideas as to how it might have happened.”
Yes, I said “prefer to believe” this time. I don’t have a good explanation for life’s origin, though I have spent a good deal of my spare time over the past 30 years looking for one.
I think what’s happening here is that the theist’s preexisting belief about a creator god is causing them to privilege the hypothesis of divine RNA-creation.
The trouble is, you seem to be privileging it too. The way you’ve set up the scenario makes it seem like there are two hypotheses: (1) goddidit, (2) some unknown natural process.
But (2) is actually a set of zillions of potential processes, many of which have a far better prior than Yahweh and the Thousand Claims of Scripture, even if we can’t actually choose one for sure right now. Taken together, all their probability mass dwarfs that of the goddidit hypothesis.
You don’t have to know all the answers to say “you’re (almost certainly) wrong.”
I don’t see any reasons why (2) - unknown natural process—gets to benefit from being a “set of zillions of potential processes, many of which have a far better prior” and (1) - goddidit—does not.
If you want to sum the probability of a hypothesis by performing some weighted sum over the set of zillions of it’s neighbors in hypothesis space, that’s fine. But if that is your criteria, you need to apply it equally to the other set of hypothesises you are considering—instead of considering only one specific example.
Bostrom’s simulation argument gives us one potential generator of ‘goddidits’, and a likely high prior for superintelligent aliens gives us another potential generator of ‘goddidits’. Either of those generators could spawn zillions of potential processes which have far better priors than Yaweh, but could look similar.
None of this leads to any specific conclusion—I’m just pointing out an unfairness in your methodology.
I don’t see any reasons why (2) - unknown natural process—gets to benefit from being a “set of zillions of potential processes, many of which have a far better prior” and (1) - goddidit—does not.
You’re quite right. When I said this, I was thinking of “goddidit” as a set of very specific claims from a single religious tradition, which I should’ve stated.
Mmm actually you did state it as a fairly specific claim. I’m just saying one can’t fairly compare highly specific complex hypothesizes vs wide general sweeps through hypothesis-space. This is itself a good argument against the specific “yawheh did it”, but not against the more general “goddidit” which you originally were referring to:
I think what’s happening here is that the theist’s preexisting belief about a creator god is causing them to privilege the hypothesis of divine RNA-creation.
You’re right—but there is another side to this coin. An atheist has a top-level belief (or it’s negation) which sends down cascading priors and privileges naturalistic hypothesizes. So far this has worked splendidly well across the landscape.
But there is no guarantee this will work everywhere forever, and it’s at least possible that eventually we may flip or find an exception for the top-level prior—for example we may eventually find that pretty much everything has a naturalistic explanation except the origin of life—which turns out to have been seeded by alien super-intelligence (ala Francis Crick) - for example.
This is itself a good argument against the specific “yawheh did it”, but not against the more general “goddidit”
[...]
An atheist has a top-level belief (or it’s negation) which sends down cascading priors and privileges naturalistic hypothesizes. So far this has worked splendidly well across the landscape.
But there is no guarantee this will work everywhere forever, and it’s at least possible that eventually we may flip...
I entirely agree. While I don’t know of any good reasons to think the origin of life was not a happy accident, it is not inconceivable a priori (simulations, seeding etc.).
When I describe myself as an atheist (which I try not to do), I really mean that
(1) all the anthropomorphic creation myths are really laughable,
(2) there’s not much positive evidence for less laughable creators, and
(3) even if you showed me evidence for a creator, I would be inclined toward what I will call meta-naturalism—i.e., still wanting to know how the hell the creator came to be.
Basically, I doubt the existence of gods that are totally ontologically distinct from creatures.
Bostrom’s simulation argument does NOT give us a generator of “goddidits” regarding the origin of life and the universe, because implicit in the question “How did life originate?” is a desire to know the ultimate root (if there is one), and us being in a simulation just gives us some more living beings (the simulators “above”) to ask our questions about. Where did life in the universe “one level above us” come from? Where did our simulator/parent universe originate?
There is nothing unfair in dismissing “A MIRACLE!” in comparison to the set of plausible naturalistic processes that could explain a given phenomenon. And to second SarahC, it’s somewhat incoherent to talk about non-naturalistic processes in the first place. You need to be very clear as to what you’re suggesting when you suggest “god did it”. But, no one here is suggesting that, so I’ll stop tangenting into arguing against theists that don’t seem to be present.
You don’t have to know all the answers to say “you’re (almost certainly) wrong.”
Well, I certainly don’t have to know all the answers in order to think that. But my brand of atheism tells me that I ought to have at least some of the answers before saying that.
There are no chemically sound models for creating life from Miller-Urey building blocks. [...] There are some models which have life starting with RNA, and some which have life starting with lipids, or iron-sulfide minerals or even (pace Tim) starting with clay. But you didn’t mention those more recent and plausible theories.
Thanks for catching me in this error. I was very vaguely familiar with those theories, but not enough to realize that they require source materials not available from Miller-Urey building blocks.
The problem I see is not so much with the source materials or “building blocks”. It is putting them together into something that reproduces itself. When Miller performed his experiment, we had no idea how life worked at the mechanical level. Even amino acids seemed somehow magic. So when Miller showed they are not magic, it seemed like a big deal.
Now we know how life works mechanically. It is pretty complicated. It is difficult to imagine something much simpler that would still work. Putting the “building blocks” together in a way that works currently seems “uphill” thermodynamically and very much uphill in terms of information. IMHO, we are today farther from a solution than we thought we were back in 1953.
But, isn’t the issue not only the amount of information required but also the amount of time and space that was available to work with?
To pick one scientific paper which I think summarizes what you’re talking about, this paper discusses “[...][t]he implausibility of the suggestion that complicated cycles could self-organize, and the importance of learning more about the potential of surfaces to help organize simpler cycles[...]”.
The chemistry discussed in that paper is well above my head, but I can still read it well enough to conclude that it seems to fallaciously arrive at probabilistic-sounding conclusions (i.e. “To postulate one fortuitously catalyzed reaction, perhaps catalyzed by a metal ion, might be reasonable, but to postulate a suite of them is to appeal to magic.”) without actually doing any probability calculations. It’s not enough to point out that the processes required to bootstrap a citric acid cycle are unlikely; how unlikely are they compared to the number of opportunities?
Am I missing something important? The above is my current understanding of the situation which I recognize to be low-level, and I present it primarily as an invitation for correction and edification, only secondarily as a counterargument to your claims.
It is important to realize that Orgel is a leader of one faction (I will resist the temptation to write “sect”) and he is critiquing the ideas of a different faction. Since I happen to subscribe to the ideas of the second faction, I may not be perfectly fair to Orgel here.
Orgel does not calculate probabilities in part because the ideas he is critiquing are not specific enough to permit such a calculation. Furthermore, and this is something you would need some background to appreciate, the issue here isn’t a question of a fluke coming together somewhere here on earth of the right ingredients. It is more a matter of a fluke coming together of laws of chemistry. Orgel is saying that he doubts that the cycle idea would work anywhere in this universe—it would take a suspiciously fine-tuned universe to let all those reactions work together like that. It is a reasonable argument—particularly coming from someone whose chemical intuition is as good as Orgel’s.
I think Orgel is pretty much right. The reductive citric acid cycle is a cute idea as the core of a metabolism-first theory, but it is probably too big and complicated a cycle to be realistic as the first cycle. Personally, I think that something simpler, using CO or HCN as the carbon source has a better chance of success. But until we come up with something specific and testable, the “metabolism first” faction maybe deserves Orgel’s scorn. The annoying thing is that our best ideas are untestable because they require enormous pressures and unsafe ingredients to test them. Damned frustrating when you want to criticize the other side for producing untestable theories.
Orgel was fair to the extent that he also provided a pretty good critiqueto his own faction’s ideas at about the same time. But it is possible that Sutherland’s new ideas on RNA synthesis may revive the RNA-first viewpoint.
If you really dig watching abiogenesis research, as I do, it is an exciting time to be alive. Lots of ideas, something wrong with every one of them, but sooner or later we are bound to figure it all out.
“Ok, you can believe that, but since I don’t already believe in a Creator Deity, I would prefer to believe that the first living organism on earth arose by some unknown natural process. In fact, I have some ideas as to how it might have happened.”
That’s about what I would say in the same situation, though I might go on to say that I “prefer to believe” in that hypothesis because its probability of truth seems high enough, although it is not as probable as more established theories such as common descent.
Let’s taboo “faith” from here out because otherwise I think we’re likely to fall into a definitional argument. My next question is: what actions do you feel are justified by the probability of the naturalistic abiogensis hypothesis, and why isn’t the flat statement “Life on Earth came about naturally” part of that set?
Let’s taboo “faith” from here out because otherwise I think we’re likely to fall into a definitional argument.
Ok by me.
My next question is: what actions do you feel are justified by the probability of the naturalistic abiogensis hypothesis,
Actions? I don’t need no steenkin’ hypothesis to justify actions… [Sorry, just watched the movie]
To be honest, I don’t see that it makes much difference to me whether life on earth arose spontaneously, or by directed panspermia, or as a once-in-a-multiverse fluke, or by the direction of some Omega running a sim. My actions are the same in any case. It is a fascinating question, though, even if it matters so little.
and why isn’t the flat statement “Life on Earth came about naturally” part of that set?
You are asking why I am not justified in coming out and saying it? But I am justified. I am justified in saying flatly that life on earth came about naturally. The statement is justified by my
By “taboo” I meant this LW meme which requires that you not just replace taboo’ed words by alternate symbols, but with working definitions. So, I’m still curious about your last paragraph: how is that statement justified? Why do you, why should you, feel comfortable saying and believing it? Should that comfort level be greater than you’d have saying “Earth-life was created by directed panspermia”?
Well, recall that the tabooed word is one which I sought to apply both to the theist “goddidit” and to the atheist “unknown-natural-processes-didit”. So what definition fits that word?
So how about this: “I make that statement because no other possibility fits into my current worldview, and this one fits reasonably well”. Or, if the taboo be removed, “I can’t prove it to your satisfaction. Hell, I can’t even prove it to my satisfaction. Yet I believe it, and I consider it a reasonable thing to believe. I guess I am simply taking it on faith.”
Why not just have an amount of belief proportional to the amount of evidence? That is, wouldn’t it be more rational to say “I think naturalistic self-organized abiogenesis is the most plausible solution known, and here’s why, but I’m not so confident in it that I think other possible solutions (including some we haven’t yet thought up) are implausible” and skip all this business about worldviews and proof? Proof isn’t really all that applicable to inductive reasoning, and I’m very skeptical of the idea that “X fits with my worldview” is a good reason for any significant amount of confidence that X is true.
Why not just have an amount of belief proportional to the amount of evidence?
Because, as a Bayesian, I realize that priors matter. Belief is produced by a combination of priors and evidence.
Proof isn’t really all that applicable to inductive reasoning,
Sure it is. Proof is applicable in both deductive and inductive reasoning. What you probably meant to say is that proof is not the only thing applicable to inductive reasoning.
I think that you will find that most of the reasoning that takes place in a field like abiogenesis has more of a deductive flavor than an inductive one. There just is not that much evidence available to work with.
and I’m very skeptical of the idea that “X fits with my worldview” is a good reason for any significant amount of confidence that X is true.
Well, then how do you feel about the idea that “X does not fit with my worldview” is a good reason for a significant amount of skepticism that X is true?
Seems to me that just a little bit ago you were finding a nice fit between X = “Miller-Urey-didit” and your worldview. A fit so nice that you were confident enough to set out to tell a total stranger about it.
Well, then how do you feel about the idea that “X does not fit with my worldview” is a good reason for a significant amount of skepticism that X is true?
I was thinking of “worldview” as a system of axioms against which claims are tested. For example, a religious worldview might axiomatically state that God exists and created the universe, and so any claim which violated that axiom can be discarded out of hand.
I’m realizing now that that’s not a useful definition; I was using it as shorthand for “beliefs that other people hold that aren’t updatable, unlike of course my beliefs which are totally rational because mumble mumble and the third step is profit”.
Beliefs which cannot be updated aren’t useful, but not all beliefs which might reasonably form a “worldview” are un-Bayesian. Maybe a better way to talk about worldviews is to think about beliefs which are highly depended upon; beliefs which, if they were updated, would also cause huge re-updates of lots of beliefs farther down the dependency graph. That would include both religious beliefs and the general belief in rationality, and include both un-updateable axiomatic beliefs as well as beliefs that are rationally resistant to update because a large collection of evidence already supports them.
So, I withdraw what I said earlier. Meshing with a worldview can in fact be rational support for a hypothesis, provided the worldview itself consists of rationally supported beliefs.
Okay, with that in mind:
Seems to me that just a little bit ago you were finding a nice fit between X = “Miller-Urey-didit” and your worldview. A fit so nice that you were confident enough to set out to tell a total stranger about it.
My claim that Miller-Urey is support for the hypothesis of life naturally occurring on Earth was based on the following beliefs:
The scientific research of others is good evidence even if I don’t understand the research itself, particularly when it is highly cited
The Miller-Urey experiment demonstrated that amino acids could plausibly form in early Earth conditions
Given sufficient opportunities, these amino acids could form a self-replicating pseudo-organism, from which evolution could be bootstrapped
Based on what you’ve explained I have significantly reduced my confidence in #3. My initial confidence for #3 was too high; it was based on hearing lots of talk about Miller-Urey amino acids being the building blocks of life, when I had not actually heard of specific paths for such formation that are confidently accepted by experts in the field as plausible.
Okay, so my conclusion has been adjusted (thanks!), but to bring it back to the earlier point: what about worldviews? Of the above, I think only #1 could be said to have to do with worldviews, and I still think it’s reasonable. As with your stereo amplifier example, even though I may not know enough about a subject to understand the literature myself, I can still estimate fairly well whether people who do claim to know enough about it are being scientific or pseudo-scientific, based on testability and lack of obviously fallacious reasoning.
Mis-application of that principle led me to my mistake with #3, but I think the principle itself stands.
Beliefs which cannot be updated aren’t useful, but not all beliefs which might reasonably form a “worldview” are un-Bayesian. Maybe a better way to talk about worldviews is to think about beliefs which are highly depended upon; beliefs which, if they were updated, would also cause huge re-updates of lots of beliefs farther down the dependency graph.
Yes.
Beliefs have hierarchy, and some are more top-level than others. One of the most top-level beliefs being:
a vast superintelligence exists
it has created/effected/influenced our history
If you give high weight to 1, then 2 follows and is strengthened, and this naturally guides your search for explanations for mysteries. A top-level belief sends down a massive cascade of priors that can effect how you interpret everything else.
If you hold the negation of 1 and or 2 as top-level beliefs then you look for natural explanations for everything. Arguably the negation of ‘goddidit’ as a top-level belief was a major boon to science because it tends to align with ockham’s razor.
But at the end of the day it’s not inherently irrational to hold these top-level beliefs. Francis Crick for instance looked at the origin of life problem and decided an unnatural explanation involving a superintelligence (alien) was actually a better fit.
A worldview comes into play when one jumps to #3 with Miller-Urey because it fits with one’s top-level priors. Our brain is built around hierarchical induction, so we always have top-level biases. This isn’t really an inherent weakness as there probably is no better (more efficient) way to do it. But it is still something to be aware of.
But at the end of the day it’s not inherently irrational to hold these top-level beliefs. Francis Crick for instance...
But, I don’t think Crick was talking about a “vast superintelligence”. In his paper, he talks about extraterrestrials sending out unmanned long-range spacecraft, not anything requiring what I think he or you would call superintelligence. In fact, he predicted that we would have that technology within “a few decades”, though rocket science isn’t among his many fields of expertise so I take that with a grain of salt.
A worldview comes into play when one jumps to #3 with Miller-Urey because it fits with one’s top-level priors.
I don’t think that’s quite what happened to me, though; the issue was that it didn’t fit my top-level priors. The solution wasn’t to adjust my worldview belief but to apply it more rationally; I ran into an akrasia problem and concluded #3 because I hadn’t examined my evidence well enough according to even my own standards.
The scientific research of others is good evidence even if I don’t understand the research itself, particularly when it is highly cited
Yeah, it sure sounds like a reasonable principle, doesn’t it? What could possibly be wrong with trusting something which gets mentioned so often? Well, as a skeptic who, by definition rejects arguments which get cited a lot, what do you think could be wrong with that maxim? Is it possibly something about the motivation of the people doing the citing?
What could possibly be wrong with trusting something which gets mentioned so often?
The quality of the cites is important, not just the quantity.
It’s possible for experts to be utterly wrong, even in their own field of expertise, even when they are very confident in their claims and seem to have good reason to be. However, it seems to me that the probability of that decreases with how testable their results are, the amount and quality of expertise they have, and the degree to which other experts legitimately agree with them (i.e. not just nodding along, but substantiating the claim with their own knowledge).
Since I’m not an expert in the given field, my ability to evaluate these things is limited and not entirely trustworthy. However, since I’m familiar with the most basic ideas of science and rationality, I ought to be able to differentiate pseudo-science from science pretty well, particularly if the pseudo-science is very irrational, or if the science is very sound.
That I had a mistaken impression about the implications of Miller-Urey, wherein I confused pop-science with real science, decreases my confidence that I’ve been generally doing it right. However, I still think the principles I listed above make sense, and that my primary error was in failing to notice the assumption I was making re: smoke → fire.
Excellent summary, I think. I have just a few things to add.
… it seems to me that the probability of that decreases with how testable their results are …
A claim that the (very real) process that Miller discovered was actually involved in the (also very real, but unknown) process by which life originated is pretty much the ultimate in untestable claims in science.
… the amount and quality of expertise they have …
In my own reading in this area, I quickly noticed that when the Miller experiment was cited in an origin-of-life chapter in a book that is really about something else, it was mentioned as if it were important science. But when it is mentioned in a book about the origin of life, then it is mentioned as intellectual history, almost in the way that chemistry books mention alchemy and phlogiston.
In other words, you can trust people like Orgel with expertise in this area to give you a better picture of the real state-of-knowledge, than someone like Paul Davies, say, who may be an expert on the Big Bang, but also includes chapters on origin-of-life and origin-of-man because it helps to sell more books.
The point of tabooing a word isn’t to replace it with a mark. The point is that it forces one to expand on what one means by the word and removes connotations that might not be shared by all people in a discussion.
I thought that it didn’t quite make sense to speak of non-naturalistic events at all. What would a non-naturalistic event look like?
It’s not so much that we take it “on faith.” It’s that, in a certain type of thinking (the kind of thinking where sentences represent claims about the world, claims must be backed by evidence, inferences must follow from premises) the very notion of a miracle is incoherent.
I was trying to help a friend write a role-playing game—yes, I’m a geek—and build in some kind of rigorous quantitative model of magic. It’s surprisingly frustrating. I invite anyone to try the exercise. You wind up with all kinds of tricky internal contradictions as soon as you start letting players break the laws of physics. I appreciate physics much more, having seen how incredibly irritating it is to try to give the appearance of structure and sense where there is none.
Of course, in a different mode of thinking—poetic thinking, or transcendent thinking -- you can talk about miracles. “The heavens declare the glory of God; the skies proclaim the work of his hands” is good strong poetry and (to me) has a ring of truth. But it isn’t a proposition at all!
I think if non-naturalistic means anything, it can be clarified as follows.
Assume we are running as a simulation on someone’s computer (Nick Bostrom has argued that we probably are). Our sim defines the boundaries of the world we can directly interact with, even in principle. Call that “realm” the natural.
A non-naturalistic event is an event in which the programmers interfere with the sim while it is in progress. Maybe after 9 gigayears they insert the first replicator, brute-force.
We can suspect it’s non-naturalistic because it (a) had no apparent physical causes or (b) was so unlikely as to be ridiculous (although anthropic arguments muddy that last consideration when we discuss the origin of life).
Other senses of “supernatural” I find to be incoherent.
At one point that was one of the standard examples given in support of the irreducible-complexity argument for creationism. That specific formulation has fallen out of favor recently, though, now that the evolutionary history of the eye has become more widely known (and largely because of its earlier use); the basic form of the argument is still quite common, but these days the more likely examples are bacterial flagella or similar bits of molecular machinery.
I think pointing to complex organ systems might be popular among creationists because of Darwin’s comments on the matter: in my admittedly narrow experience, creationists are likely to have read Origin of Species but quite unlikely to have read any more modern evolutionary biology. And a “disproof” of Darwin on his own terms would certainly be attractive to that mindset.
What?
Do theists really ask this?
I can’t vouch for that one in particular, but it’s very much in line with what some theists say about evolution, yes—and I’m not even talking about the self-selected idiots on Youtube; I’m referring to things I heard while working at a Roman Catholic nursing home.
Creationists do, at least rhetorically, in the half-eye-is-worthless type of argument.
Meanwhile evolution advocates sometimes ask “How do you explain nerves going totally the wrong way out of the retina?” This leads to the age old philosophical question: “Can God create a keg of beer so large that even he can get wasted?”
Interestingly enough, a friend suggested that the backwards retina thing actually makes sense. The argument goes something like this:
You don’t actually need an exact photo. You need to be able to quickly spot the thing you’re hunting, or the threat that may be coming after you, etc… Attached to the retina is a computational layer that preprocesses images (edge detection, various other bits of compression) before sending it along the optic nerve. If you sent the pure raw data, that would mean more data that needs to be sent per “image”, so more effective latency.
So the computational layer is important. Now, apparently the actual sensor cells are rather more energetically expensive than the computational layer. If you put the actual image collector in front of the computational layer, then you’d have to have a bunch more blood vessels punching through the computational layer to feed the sensor layer. That is going to leave less computational power available for compressing/preprocessing it. So you’re going to have to send more or the raw data to the brain and then wait around for it to process/react to it.
So now this leaves us with putting the computational layer in front of the sensor layer. But, once we have that, since the computational layer has to output to the optic nerve, well, it’s pretty much got to punch through somewhere. If it simply went around, the path would be longer, so there’d be higher latency, and that would be bad. Would leave you less time to react when that tiger is coming for you.
I don’t really have any references for this, it’s just something that came out a conversation with this friend, but it does seem plausible to me.
(He’s not a creationist, incidentally. The conversation was effectively an argument about whether intelligence is smarter than evolution, I was noting the backwards retina as an example of some of evolution’s stupidity/inability to “look-ahead”. He argued that actually, once one starts to look at the actual properties a vision system needs to fulfill from an engineering perspective and look at how that relates to energy flow and data latency and so on, the “backwards retina” actually might be the right way to do things after all.)
So then it is the octopus eye that is wrong, and the vertebrate eye that is right.
In any case, that the facts are (partially) explained by common descent, but not by special creation of each “kind”, makes the nature of eyes within the animal kingdom evidence for evolution rather than creation.
Sure. I was just saying that maybe the backwards retina thing might not be the best example of evolution being stupid since that particular design may not be that bad,
As far as octopuses and such, how do their eyes compare to our eyes? how quickly can they react to stuff, etc etc?
(If I’m totally wrong on what I said earlier, lemme know. I mean, it’s quite possible that the friend in question was basically totally BSing me. I hadn’t researched the subject myself in all that much detail, so… However, his argument did seem sufficiently plausible to me that at least it doesn’t seem completely nuts.)
As it usually is with amateur evolutionary explanations, one can persuasively argue that almost anything is an adaptation.
The thing is, he was claiming that we sort of figured this out in the process of trying to design artificial vision systems. ie, it wasn’t so much a “here’s a contrived after the fact explanation” as much as “later on, when we tried to figure out what sorts of design criteria, etc etc would be involved in vision systems, suddenly this made a bit more sense.”
Again, I have no references on this, but it does seem plausible.
And as it usually is with amateur engineers, one can persuasively argue that almost any existent design is inferior to a better hypothetical design.
Your saying is quotable, but it holds no weight against Psy-kosh’s point: an evolutionary adaptation that looks maladaptive to us is more likely caused by our current technical ignorance than actual maladaption.
Do you include professional biologists into the ignorant group? If so, are people justified to call any feature maladaptive? If not, why speak about adaptations whatsoever, when our ability to judge their true benefit is only an illusion caused by our technological ignorance?
Apriori, true maladaptions are rare. Evolution does not proceed by starting with hypothetical perfect beings and then slowly accumulating maladaptions.
So really, almost every feature is an adaptation by default. A maladaptive feature would have to actually harm fitness. There are certainly some cases of this you could show by engineering in a lab, but the retina is not such a case.
In the retina’s case, what we are really discussing is whether the backwards retina is a suboptimal design. But to prove that, you have to prove the existence of a more optimal design. Biologists haven’t done that.
A better route towards that would have started with comparing the mammalian/primate eye with an alternate ‘design’ - such as the cephalopod eye.
The substance of your statement basically amounted to an empty ad hominem against amateur theorists.
It was rather tongue-in-cheek than ad hominem, and intentionally so. But empty? To make up a wrong explanation which could sound convincingly to amateurs is quite easy in any science, evolution theory included. It is already acknowledged here in case of evolutionary psychology, but the arguments are valid generally for evolution.
First, I have made no statement about optimality of retina, and I don’t disagree that the question may be more complicated than it seems on the first sight. In fact, it was basically my original point.
Second, all designs are almost certainly suboptimal. Optimal means there is no place for improvement, and the prior probability that evolution produce such solutions is quite low. It is also not so hard to see why humans can sometimes notice suboptimality in evolved adaptations: evolution works only by small alterations and can be easily trapped in local optimum, overlooking a better optimum elsewhere in the design space. That’s why I was puzzled when you have written
I interpret it as “we can never confidently say that any adaptation is suboptimal”, or even “everything in nature is by default optimal, unless proven otherwise”, which is a really strong statement. Do you maintain that the perceived maladaptivity of human appendix is also probably an illusion created by our insufficient knowledge of bowel engineering?
I agree with much of what you say, yet . .
Yes, and I was pointing out that this applies equally to biologists acting as amateur engineers.
Your statement seemed to me to be a blanket substance-less dismissal of the original discussion on why the retina’s design may not be as suboptimal as it appears to amateur engineers.
I doubt your certainty. Optimality is well understood and well defined in math and comptuer science, and evolutionary algorithms can easily produce optimal solutions for well defined problems given sufficient time & space. Optimality in biology is necessarily a fuzzy concept—the fitness function is quite complex.
Nonetheless, parallel evolution gives us an idea of how evolution can reliably produce designs that roughly fill or populate optimums in the fitness landscape. The exact designs are never exactly the same, but this is probably more a result of the fuziness of the optimum region in the different but similar fitness landscapes than a failure of evolution.
I think this is a mischaracterization of evolutionary algorithms—they are actually extremely robust against getting stuck in local optimums. This is in fact their main claim to fame, their advantage vs simpler search approaches.
You somewhat overinterpret, and also remember that the quote is my summarization of someone else’s point. Nonetheless, I stand by the general form of the statement.
It is extremely difficult to say that a particular adaptation is suboptimal unless you can actually prove it by improving the ‘design’ through genetic engineering.
Given what we currently know, it is wise to have priors such that by default one assumes that perceived suboptimal designs in organisms are more likely a result of our own ignorance.
wnoise answers this for me below, and shows the validity of the prior I advocate
I agree with your basic point, but this might not have been the best example. We’re now fairly sure that the appendix is useful for providing a reservoir that keeps friendly gut bacteria around even when diarrhea flushes out the rest of the GI tract.
Overall, probably now maladaptive for the average first world citizen. For the average third world citizen, or in the environment of evolutionary adaptation, that’s less clear.
I don’t know enough about the computational details to comment on those aspects but will note that some sea creatures don’t have the reversed retina. So it does seem like it really is in humans an artifact of how we evolved.
Oh, yes. It is asked pretty regularly in the forums that deal with such things. Places like talk.origins.
Creationists have a world-view which places God-the-creator at the base of all explanations regarding the nature of reality. Remove Him and much that was explained is no longer explained. Asking an “evolutionist” to explain the natural existence of the eye—a mechanism of considerable intricacy and sophistication—is perfectly reasonable in this context, particularly for someone who doesn’t understand natural selection at all. Which most people, theist or atheist, don’t understand.
Even theists who understand natural selection, people like Behe or Dembski, can find evolutionary explanation unconvincing when they change the question from “How did the eye become so nearly perfect?” to something like “How did eyes get started, anyhow?”. To be fair, they find the explanations unconvincing because the standard explanations really are unconvincing and they are unwilling to accept a promissory note that better explanations will be forthcoming in time.
There is some truth to the claim that even atheists currently take some things “on faith”. The naturalistic origin of life, for example.
Hold on, the naturalistic origin of life is pretty plausible based on current understanding (Miller-Urey showed amino acid development would be very plausible, and from there there are a number of AIUI chemically sound models for those building blocks naturally forming self-replicating organisms or pseudo-organisms).
Are you genuinely arguing that its probability is so low that it would be less productive to investigate naturalistic abiogenesis mechanisms than it would be to look for new hypotheses? Or, alternately, do you have a more specific idea of what minimum level of probability it takes for a hypothesis be “plausible” rather than “being taken on faith”?
And that claim by you is based on … what exactly? Experiments you have performed? Books you have read explaining the theory to your satisfaction with no obvious hand waving? Books like the ones we all have read describing Darwin’s theory of evolution through natural selection? Or maybe you have encountered a section in a library filled with technical material beyond your comprehension, but which you are pretty sure you could comprehend with enough effort? For me, something in this category would be stereo amplifiers—I’ve seen the books so I know there is nothing supernatural involved, though I can’t explain it myself.
From what you write below, I’m guessing your background puts you at roughly this level regarding abiogenesis. Except, the difference is that there is no library section filled with technical material explaining how life originated from non-life. So, I think you are going on faith.
No there aren’t. There is not a single plausible theory in existence right now claiming that life originates from amino acids arising from a Miller-Urey type of process. There are no chemically sound models for creating life from Miller-Urey building blocks.
There are some models which have life starting with RNA, and some which have life starting with lipids, or iron-sulfide minerals or even (pace Tim) starting with clay. But you didn’t mention those more recent and plausible theories. Instead you went on faith.
No. Not at all. I don’t have a clue as to what it would even mean to look for, let alone investigate a non-naturalistic hypothesis.
What I am saying is this: Suppose I have before me a theist who claims that a Deity must have been the cause of the Big Bang. “Something from nothing” and all that. Suppose further that my own version of atheism is so completely non-evangelical and my knowledge of cosmology so weak that I say to him, “Could be! I don’t believe that a Deity was involved, but I don’t have any evidence to rule it out.”
So that is the supposition. Next, suppose he says “Furthermore, I think the Deity must have been involved in the origin of life, back 3+ billion years ago. From what I know of chemistry and biochemistry, that could not have been spontaneous.” I would tell him that I too know quite a bit about chemistry and biochemistry, and that there are many, many clues indicating that life based on RNA probably existed before modern life based on DNA and amino acids and proteins. There is strong evidence that life in its current form came from something more primitive.
Now, suppose he says “Yes, I understand all that evidence. But you still have no theory to explain how life based on RNA might have started. All you have is handwaving. My belief, since I already believe in a Creator-Deity for the Big Bang, is that a Creator-Deity was also involved in the origin of the RNA World.” If he said that, then I would answer, “Ok, you can believe that, but since I don’t already believe in a Creator Deity, I would prefer to believe that the first living organism on earth arose by some unknown natural process. In fact, I have some ideas as to how it might have happened.”
Yes, I said “prefer to believe” this time. I don’t have a good explanation for life’s origin, though I have spent a good deal of my spare time over the past 30 years looking for one.
I think what’s happening here is that the theist’s preexisting belief about a creator god is causing them to privilege the hypothesis of divine RNA-creation.
The trouble is, you seem to be privileging it too. The way you’ve set up the scenario makes it seem like there are two hypotheses: (1) goddidit, (2) some unknown natural process.
But (2) is actually a set of zillions of potential processes, many of which have a far better prior than Yahweh and the Thousand Claims of Scripture, even if we can’t actually choose one for sure right now. Taken together, all their probability mass dwarfs that of the goddidit hypothesis.
You don’t have to know all the answers to say “you’re (almost certainly) wrong.”
I don’t see any reasons why (2) - unknown natural process—gets to benefit from being a “set of zillions of potential processes, many of which have a far better prior” and (1) - goddidit—does not.
If you want to sum the probability of a hypothesis by performing some weighted sum over the set of zillions of it’s neighbors in hypothesis space, that’s fine. But if that is your criteria, you need to apply it equally to the other set of hypothesises you are considering—instead of considering only one specific example.
Bostrom’s simulation argument gives us one potential generator of ‘goddidits’, and a likely high prior for superintelligent aliens gives us another potential generator of ‘goddidits’. Either of those generators could spawn zillions of potential processes which have far better priors than Yaweh, but could look similar.
None of this leads to any specific conclusion—I’m just pointing out an unfairness in your methodology.
You’re quite right. When I said this, I was thinking of “goddidit” as a set of very specific claims from a single religious tradition, which I should’ve stated.
Mmm actually you did state it as a fairly specific claim. I’m just saying one can’t fairly compare highly specific complex hypothesizes vs wide general sweeps through hypothesis-space. This is itself a good argument against the specific “yawheh did it”, but not against the more general “goddidit” which you originally were referring to:
You’re right—but there is another side to this coin. An atheist has a top-level belief (or it’s negation) which sends down cascading priors and privileges naturalistic hypothesizes. So far this has worked splendidly well across the landscape.
But there is no guarantee this will work everywhere forever, and it’s at least possible that eventually we may flip or find an exception for the top-level prior—for example we may eventually find that pretty much everything has a naturalistic explanation except the origin of life—which turns out to have been seeded by alien super-intelligence (ala Francis Crick) - for example.
I entirely agree. While I don’t know of any good reasons to think the origin of life was not a happy accident, it is not inconceivable a priori (simulations, seeding etc.).
When I describe myself as an atheist (which I try not to do), I really mean that
(1) all the anthropomorphic creation myths are really laughable,
(2) there’s not much positive evidence for less laughable creators, and
(3) even if you showed me evidence for a creator, I would be inclined toward what I will call meta-naturalism—i.e., still wanting to know how the hell the creator came to be.
Basically, I doubt the existence of gods that are totally ontologically distinct from creatures.
Bostrom’s simulation argument does NOT give us a generator of “goddidits” regarding the origin of life and the universe, because implicit in the question “How did life originate?” is a desire to know the ultimate root (if there is one), and us being in a simulation just gives us some more living beings (the simulators “above”) to ask our questions about. Where did life in the universe “one level above us” come from? Where did our simulator/parent universe originate?
There is nothing unfair in dismissing “A MIRACLE!” in comparison to the set of plausible naturalistic processes that could explain a given phenomenon. And to second SarahC, it’s somewhat incoherent to talk about non-naturalistic processes in the first place. You need to be very clear as to what you’re suggesting when you suggest “god did it”. But, no one here is suggesting that, so I’ll stop tangenting into arguing against theists that don’t seem to be present.
Well, I certainly don’t have to know all the answers in order to think that. But my brand of atheism tells me that I ought to have at least some of the answers before saying that.
Different strokes for different folks.
Thanks for catching me in this error. I was very vaguely familiar with those theories, but not enough to realize that they require source materials not available from Miller-Urey building blocks.
The problem I see is not so much with the source materials or “building blocks”. It is putting them together into something that reproduces itself. When Miller performed his experiment, we had no idea how life worked at the mechanical level. Even amino acids seemed somehow magic. So when Miller showed they are not magic, it seemed like a big deal.
Now we know how life works mechanically. It is pretty complicated. It is difficult to imagine something much simpler that would still work. Putting the “building blocks” together in a way that works currently seems “uphill” thermodynamically and very much uphill in terms of information. IMHO, we are today farther from a solution than we thought we were back in 1953.
But, isn’t the issue not only the amount of information required but also the amount of time and space that was available to work with?
To pick one scientific paper which I think summarizes what you’re talking about, this paper discusses “[...][t]he implausibility of the suggestion that complicated cycles could self-organize, and the importance of learning more about the potential of surfaces to help organize simpler cycles[...]”.
The chemistry discussed in that paper is well above my head, but I can still read it well enough to conclude that it seems to fallaciously arrive at probabilistic-sounding conclusions (i.e. “To postulate one fortuitously catalyzed reaction, perhaps catalyzed by a metal ion, might be reasonable, but to postulate a suite of them is to appeal to magic.”) without actually doing any probability calculations. It’s not enough to point out that the processes required to bootstrap a citric acid cycle are unlikely; how unlikely are they compared to the number of opportunities?
Am I missing something important? The above is my current understanding of the situation which I recognize to be low-level, and I present it primarily as an invitation for correction and edification, only secondarily as a counterargument to your claims.
It is important to realize that Orgel is a leader of one faction (I will resist the temptation to write “sect”) and he is critiquing the ideas of a different faction. Since I happen to subscribe to the ideas of the second faction, I may not be perfectly fair to Orgel here.
Orgel does not calculate probabilities in part because the ideas he is critiquing are not specific enough to permit such a calculation. Furthermore, and this is something you would need some background to appreciate, the issue here isn’t a question of a fluke coming together somewhere here on earth of the right ingredients. It is more a matter of a fluke coming together of laws of chemistry. Orgel is saying that he doubts that the cycle idea would work anywhere in this universe—it would take a suspiciously fine-tuned universe to let all those reactions work together like that. It is a reasonable argument—particularly coming from someone whose chemical intuition is as good as Orgel’s.
I think Orgel is pretty much right. The reductive citric acid cycle is a cute idea as the core of a metabolism-first theory, but it is probably too big and complicated a cycle to be realistic as the first cycle. Personally, I think that something simpler, using CO or HCN as the carbon source has a better chance of success. But until we come up with something specific and testable, the “metabolism first” faction maybe deserves Orgel’s scorn. The annoying thing is that our best ideas are untestable because they require enormous pressures and unsafe ingredients to test them. Damned frustrating when you want to criticize the other side for producing untestable theories.
Orgel was fair to the extent that he also provided a pretty good critiqueto his own faction’s ideas at about the same time. But it is possible that Sutherland’s new ideas on RNA synthesis may revive the RNA-first viewpoint.
If you really dig watching abiogenesis research, as I do, it is an exciting time to be alive. Lots of ideas, something wrong with every one of them, but sooner or later we are bound to figure it all out.
That’s about what I would say in the same situation, though I might go on to say that I “prefer to believe” in that hypothesis because its probability of truth seems high enough, although it is not as probable as more established theories such as common descent.
Let’s taboo “faith” from here out because otherwise I think we’re likely to fall into a definitional argument. My next question is: what actions do you feel are justified by the probability of the naturalistic abiogensis hypothesis, and why isn’t the flat statement “Life on Earth came about naturally” part of that set?
Ok by me.
Actions? I don’t need no steenkin’ hypothesis to justify actions… [Sorry, just watched the movie]
To be honest, I don’t see that it makes much difference to me whether life on earth arose spontaneously, or by directed panspermia, or as a once-in-a-multiverse fluke, or by the direction of some Omega running a sim. My actions are the same in any case. It is a fascinating question, though, even if it matters so little.
You are asking why I am not justified in coming out and saying it? But I am justified. I am justified in saying flatly that life on earth came about naturally. The statement is justified by my
By “taboo” I meant this LW meme which requires that you not just replace taboo’ed words by alternate symbols, but with working definitions. So, I’m still curious about your last paragraph: how is that statement justified? Why do you, why should you, feel comfortable saying and believing it? Should that comfort level be greater than you’d have saying “Earth-life was created by directed panspermia”?
Well, recall that the tabooed word is one which I sought to apply both to the theist “goddidit” and to the atheist “unknown-natural-processes-didit”. So what definition fits that word?
So how about this: “I make that statement because no other possibility fits into my current worldview, and this one fits reasonably well”. Or, if the taboo be removed, “I can’t prove it to your satisfaction. Hell, I can’t even prove it to my satisfaction. Yet I believe it, and I consider it a reasonable thing to believe. I guess I am simply taking it on faith.”
Why not just have an amount of belief proportional to the amount of evidence? That is, wouldn’t it be more rational to say “I think naturalistic self-organized abiogenesis is the most plausible solution known, and here’s why, but I’m not so confident in it that I think other possible solutions (including some we haven’t yet thought up) are implausible” and skip all this business about worldviews and proof? Proof isn’t really all that applicable to inductive reasoning, and I’m very skeptical of the idea that “X fits with my worldview” is a good reason for any significant amount of confidence that X is true.
Because, as a Bayesian, I realize that priors matter. Belief is produced by a combination of priors and evidence.
Sure it is. Proof is applicable in both deductive and inductive reasoning. What you probably meant to say is that proof is not the only thing applicable to inductive reasoning.
I think that you will find that most of the reasoning that takes place in a field like abiogenesis has more of a deductive flavor than an inductive one. There just is not that much evidence available to work with.
Well, then how do you feel about the idea that “X does not fit with my worldview” is a good reason for a significant amount of skepticism that X is true?
Seems to me that just a little bit ago you were finding a nice fit between X = “Miller-Urey-didit” and your worldview. A fit so nice that you were confident enough to set out to tell a total stranger about it.
I was thinking of “worldview” as a system of axioms against which claims are tested. For example, a religious worldview might axiomatically state that God exists and created the universe, and so any claim which violated that axiom can be discarded out of hand.
I’m realizing now that that’s not a useful definition; I was using it as shorthand for “beliefs that other people hold that aren’t updatable, unlike of course my beliefs which are totally rational because mumble mumble and the third step is profit”.
Beliefs which cannot be updated aren’t useful, but not all beliefs which might reasonably form a “worldview” are un-Bayesian. Maybe a better way to talk about worldviews is to think about beliefs which are highly depended upon; beliefs which, if they were updated, would also cause huge re-updates of lots of beliefs farther down the dependency graph. That would include both religious beliefs and the general belief in rationality, and include both un-updateable axiomatic beliefs as well as beliefs that are rationally resistant to update because a large collection of evidence already supports them.
So, I withdraw what I said earlier. Meshing with a worldview can in fact be rational support for a hypothesis, provided the worldview itself consists of rationally supported beliefs.
Okay, with that in mind:
My claim that Miller-Urey is support for the hypothesis of life naturally occurring on Earth was based on the following beliefs:
The scientific research of others is good evidence even if I don’t understand the research itself, particularly when it is highly cited
The Miller-Urey experiment demonstrated that amino acids could plausibly form in early Earth conditions
Given sufficient opportunities, these amino acids could form a self-replicating pseudo-organism, from which evolution could be bootstrapped
Based on what you’ve explained I have significantly reduced my confidence in #3. My initial confidence for #3 was too high; it was based on hearing lots of talk about Miller-Urey amino acids being the building blocks of life, when I had not actually heard of specific paths for such formation that are confidently accepted by experts in the field as plausible.
Okay, so my conclusion has been adjusted (thanks!), but to bring it back to the earlier point: what about worldviews? Of the above, I think only #1 could be said to have to do with worldviews, and I still think it’s reasonable. As with your stereo amplifier example, even though I may not know enough about a subject to understand the literature myself, I can still estimate fairly well whether people who do claim to know enough about it are being scientific or pseudo-scientific, based on testability and lack of obviously fallacious reasoning.
Mis-application of that principle led me to my mistake with #3, but I think the principle itself stands.
Yes.
Beliefs have hierarchy, and some are more top-level than others. One of the most top-level beliefs being:
a vast superintelligence exists
it has created/effected/influenced our history
If you give high weight to 1, then 2 follows and is strengthened, and this naturally guides your search for explanations for mysteries. A top-level belief sends down a massive cascade of priors that can effect how you interpret everything else.
If you hold the negation of 1 and or 2 as top-level beliefs then you look for natural explanations for everything. Arguably the negation of ‘goddidit’ as a top-level belief was a major boon to science because it tends to align with ockham’s razor.
But at the end of the day it’s not inherently irrational to hold these top-level beliefs. Francis Crick for instance looked at the origin of life problem and decided an unnatural explanation involving a superintelligence (alien) was actually a better fit.
A worldview comes into play when one jumps to #3 with Miller-Urey because it fits with one’s top-level priors. Our brain is built around hierarchical induction, so we always have top-level biases. This isn’t really an inherent weakness as there probably is no better (more efficient) way to do it. But it is still something to be aware of.
But, I don’t think Crick was talking about a “vast superintelligence”. In his paper, he talks about extraterrestrials sending out unmanned long-range spacecraft, not anything requiring what I think he or you would call superintelligence. In fact, he predicted that we would have that technology within “a few decades”, though rocket science isn’t among his many fields of expertise so I take that with a grain of salt.
I don’t think that’s quite what happened to me, though; the issue was that it didn’t fit my top-level priors. The solution wasn’t to adjust my worldview belief but to apply it more rationally; I ran into an akrasia problem and concluded #3 because I hadn’t examined my evidence well enough according to even my own standards.
Yeah, it sure sounds like a reasonable principle, doesn’t it? What could possibly be wrong with trusting something which gets mentioned so often? Well, as a skeptic who, by definition rejects arguments which get cited a lot, what do you think could be wrong with that maxim? Is it possibly something about the motivation of the people doing the citing?
The quality of the cites is important, not just the quantity.
It’s possible for experts to be utterly wrong, even in their own field of expertise, even when they are very confident in their claims and seem to have good reason to be. However, it seems to me that the probability of that decreases with how testable their results are, the amount and quality of expertise they have, and the degree to which other experts legitimately agree with them (i.e. not just nodding along, but substantiating the claim with their own knowledge).
Since I’m not an expert in the given field, my ability to evaluate these things is limited and not entirely trustworthy. However, since I’m familiar with the most basic ideas of science and rationality, I ought to be able to differentiate pseudo-science from science pretty well, particularly if the pseudo-science is very irrational, or if the science is very sound.
That I had a mistaken impression about the implications of Miller-Urey, wherein I confused pop-science with real science, decreases my confidence that I’ve been generally doing it right. However, I still think the principles I listed above make sense, and that my primary error was in failing to notice the assumption I was making re: smoke → fire.
Excellent summary, I think. I have just a few things to add.
A claim that the (very real) process that Miller discovered was actually involved in the (also very real, but unknown) process by which life originated is pretty much the ultimate in untestable claims in science.
In my own reading in this area, I quickly noticed that when the Miller experiment was cited in an origin-of-life chapter in a book that is really about something else, it was mentioned as if it were important science. But when it is mentioned in a book about the origin of life, then it is mentioned as intellectual history, almost in the way that chemistry books mention alchemy and phlogiston.
In other words, you can trust people like Orgel with expertise in this area to give you a better picture of the real state-of-knowledge, than someone like Paul Davies, say, who may be an expert on the Big Bang, but also includes chapters on origin-of-life and origin-of-man because it helps to sell more books.
The point of tabooing a word isn’t to replace it with a mark. The point is that it forces one to expand on what one means by the word and removes connotations that might not be shared by all people in a discussion.
I thought that it didn’t quite make sense to speak of non-naturalistic events at all. What would a non-naturalistic event look like?
It’s not so much that we take it “on faith.” It’s that, in a certain type of thinking (the kind of thinking where sentences represent claims about the world, claims must be backed by evidence, inferences must follow from premises) the very notion of a miracle is incoherent.
I was trying to help a friend write a role-playing game—yes, I’m a geek—and build in some kind of rigorous quantitative model of magic. It’s surprisingly frustrating. I invite anyone to try the exercise. You wind up with all kinds of tricky internal contradictions as soon as you start letting players break the laws of physics. I appreciate physics much more, having seen how incredibly irritating it is to try to give the appearance of structure and sense where there is none.
Of course, in a different mode of thinking—poetic thinking, or transcendent thinking -- you can talk about miracles. “The heavens declare the glory of God; the skies proclaim the work of his hands” is good strong poetry and (to me) has a ring of truth. But it isn’t a proposition at all!
I think if non-naturalistic means anything, it can be clarified as follows.
Assume we are running as a simulation on someone’s computer (Nick Bostrom has argued that we probably are). Our sim defines the boundaries of the world we can directly interact with, even in principle. Call that “realm” the natural.
A non-naturalistic event is an event in which the programmers interfere with the sim while it is in progress. Maybe after 9 gigayears they insert the first replicator, brute-force.
We can suspect it’s non-naturalistic because it (a) had no apparent physical causes or (b) was so unlikely as to be ridiculous (although anthropic arguments muddy that last consideration when we discuss the origin of life).
Other senses of “supernatural” I find to be incoherent.
At one point that was one of the standard examples given in support of the irreducible-complexity argument for creationism. That specific formulation has fallen out of favor recently, though, now that the evolutionary history of the eye has become more widely known (and largely because of its earlier use); the basic form of the argument is still quite common, but these days the more likely examples are bacterial flagella or similar bits of molecular machinery.
I think pointing to complex organ systems might be popular among creationists because of Darwin’s comments on the matter: in my admittedly narrow experience, creationists are likely to have read Origin of Species but quite unlikely to have read any more modern evolutionary biology. And a “disproof” of Darwin on his own terms would certainly be attractive to that mindset.
http://www.youtube.com/watch?v=jW6yeMj3ORE
I laughed, but I wonder if he wasn’t just deliberately trolling. He had that look on his face.