What you are talking about is a lay sense of evolution. Sure, things change, and the more adapted thing should survive with higher frequency, this much is obvious even to creationists. It is also obvious to me (as it was to Aristotle), that things which are in motion tend to come to rest. Turns out, it’s not really true. Just because a theory is intuitive, doesn’t mean that’s how the world really works. You only need to think about Heliocentrism, let alone something like quantum physics.
One problem that Darwin had was the lack of mechanism for evolution (i.e. genetics). If I were alive at the time he wrote his books, I would have liked his theory, but would have been forced to acknowledge that it does not truly explain how the world works. I am told that now this is all solved, but have been taking that largely on faith.
It also may be that the theory is wrong, but there is no better theory to replace it, a la physics in 1900. If that were the case, I’d like to know that too.
We should expect some amount of evolution by natural selection ‘a priori’, from various obvious premises such as
(1) There is a reproduction process in which characteristics are inherited
(2) Things with X characteristics in Y environment die/live
etc.
There seems to be an absence of similarly parsimonious explanations, and the account given by natural selection is compelling. I suspect that even a small amount of knowledge of the empirical evidence for natural selection would establish a lower bound on the share of evolution it causes, such that searching for equally significant factors for evolution of life in general should be expected to fail.
If one set up a mathematical representation of a population that took into account characteristics, life, and death, etc. then natural selection would be the name for a provable behaviour of the system, even if the system were just axiomatised by more basic facts such as (1) and (2). I’m not convinced that the same is true of Aristotelian physics.
I struggle far more to fabricate accounts of our observations without natural selection than I did to get to grips with Newtonian mechanics. As in, accounts that don’t leave me more confused (e.g. ‘God did it’, which is a mysterious non-answer).
Quantum mechanics I do not know well enough (and I’m not sure anyone does) at the level where mathematical reductionism meets theoretical physics, but I would not be surprised if it turned out to be extremely parsimonious given even a small number of our empirical observations.
Heliocentrism also seems much more contingent than natural selection, although possibly less than one thinks, given how prevalent star-planet systems are.
(1) There is a reproduction process in which characteristics are inherited (2) Things with X characteristics in Y environment die/live etc.
This merely says that the surviving characteristics will move towards optimal in an unspecified range, assuming there are no other significant influences.
It is not explained how exactly the things with less likely characteristics have appeared in the first place. Is there perhaps another process that causes non-optimality? How could you know the process is not actually stronger than the process of natural selection?
It is also not obvious that this process of improvement can cross boundaries between species. You proved that a healthy dog is more likely to survive than a sick dog. You didn’t prove that the super-healthy dog will evolve to a lion or an eagle.
So this naive observation is actually not in contradiction with creationism. (Of course only after the creationism is updated to include it. But hey, scientists change their opinions, too.)
To move further, we need to know that the information which encodes the organism can change randomly (mutation), and that all species use the very same mechanism, so it is possible in theory to modify the information step by step starting with dog and ending with an eagle, in each step getting organisms which would be optimized for some environment. We need some kind of “universal DNA” hypothesis, even if we don’t know the exact formula for the DNA. And it’s not really obvious that dogs and eagles and fish and trees are all encoded in the same way.
On the other hand, once we have a microscope, the “universal DNA” hypothesis becomes rather simple to prove, because it is enough to explore what we have here and now.
I agree that understanding the extent to which natural selection generated things is easier nowadays than it was previously.
So this naive observation is actually not in contradiction with creationism.
I’m not concerned here with logical disproofs of creationism, moreso with something like arguing that time spent {worrying that evolution by natural selection is significantly overrated} is probably misallocated, or arguing that people are privileging the question of ‘Is evolution by natural selection a good explanation?’ (I’m not entirely sure what my motivation is, but it feels like it’s at least partly something along those lines.)
I also think that there’s a lot of hard-to-enumerate background information available to a person nowadays that should be enough for a naturalistic reductionist to intuit that evolution will not arise from bolted-on complex mechanisms like creation, but rather from mechanisms like natural selection that are inherent to populations with a few basic properties that we have actually observed (e.g. finite lifespans that vary according to characteristic-environment interaction, inheritance of characteristics, etc.). It’s possible you understand this and I’m misinterpreting the point at which you’re challenging my argument, but I would very strongly disexpect somebody thinking like me along the lines of ‘provable properties of populations under observed axioms’ (or the probabilistic/continuous generalisation thereof) to be talking about creationism; rather, I would expect challenges to come in the form of other equally basic, low-complexity processes that arise from what we already know.
I’m not sure DNA/the exact method of inheritance is relevant; I would still consider it to be a win for natural selection if we had, say, Lamarckism/inheritance of acquired characteristics/epigenetics as a significant force.
Well, we have tons of observation that nature can be understood, and that the useful explanations do not involve gods or magic. So yes, it would be a reasonable prior expectation for the origins of species, too.
I agree that certainly some evolution would follow from your premises (1) and (2). But imagine that we also have independent evidence that Earth is 1 million years old. In that case, I’d be forced to say that the Theory of Evolution can’t account for the evidence of life we observe, given mutation rates, etc. This is the sort of thing I am worried about when I say I haven’t looked at the evidence. As far as I know there isn’t any contradictory evidence of this sort, but there may be specific challenges that aren’t well-explained. Creationists like to cite irreducible organs and claim that those exist (i.e. where it can’t evolve from anything that has any evolutionary advantage) and are contrary to the theory. I know about this objection, but it would be a lot of work to truly evaluate it in depth.
As far as having an alternative: this isn’t necessary. I’d be reluctant to go with “God did it”, so I’d be fine with “the theory explains 95% of the evidence, and about the other 5% we don’t know yet, and we have no better theory”.
Just realised you’re the post author, so: Thanks for posting this, it’s something I’ve wondered about in relation to myself, as well. :)
1: No tentacles
But imagine that we also have independent evidence that Earth is 1 million years old.
This reminds me of something Eliezer once said—”How would I explain the event of my left arm being replaced by a blue tentacle? The answer is that I wouldn’t. It isn’t going to happen.” We do not observe a young (even 10^6) Earth, and by suggesting the possibility of one as counterevidence against the strength of the ‘a priori’ reasoning I advocated, you must be smuggling in a circular assumption that young Earth models have significant probability.
Your argument as I understand it is roughly that since my a priori reasoning would fail in young Earth scenarios, then that reasoning is unreliable. But if our prior for young Earth scenarios is extremely low, then it will only very rarely happen that my reasoning will fail in that particular way. Therefore for your argument to go through, you would have to place a high prior probability on young Earth scenarios.
To put it another another way: If observing a young Earth would be evidence against my a priori reasoning, then by conservation of expected evidence, our actual observation of a non-young Earth must be evidence in favour of that reasoning.
People in a modern day situation, and LW’ers in particular, are better placed to understand that ‘naturalistic’ explanations are preferable, and that magic ones should incur huge complexity penalties. Therefore we should have low priors on young Earths, because most of our probability will be concentrated in models where intelligent life arises from nonintelligent (hence slow) processes as opposed to intelligent (e.g. God) processes.
Moreover, the more intelligent the process that generated us, the more we push the explanatory buck back onto that process. God is an extreme case where the mystery of the apparent improbability of human intelligence is replaced with the mystery of the apparent improbability of divine intelligence. But even less extreme cases like superhumanly (but still decidedly ‘finitely intelligent’) entities simulating us incurs a penalty for passing the explanatory buck back. Natural selection is so elegant and formidable because it is an existing behaviour of what we already observe.
2: Insanity screens off charity
Creationists like to cite irreducible organs
If—even before accepting evolution by natural selection—you can put an extremely high probability on creationists spewing objections like ‘irreducible organs’ regardless of the veracity of evolution by natural selection, then you can pretty much write off the counterarguments of creationists, because your observation of creationists making these arguments is extremely weak evidence that there is anything to these counterarguments. Now, this is circular if your only reason for not taking creationists seriously is that they are wrong natural selection/irreducible organs, but there’s ‘any number’ of other reasons to suspect creationists are engaging in motivated cognition.
The same way that if natural selection provides a substantial portion of the explanation of evolution, then, you need look no further, if cognitive biases/sociology provide a substantial portion of or even all of the explanation for creationists talking about irreducible organs, then their actual counterarguments are screened off by your prior knowledge of what causes them to deploy those counterarguments; you should be less inclined to consider their arguments than a random string generator that happened to output a sentence that reads as a counterargument against natural selection.
I think you are interpreting my comments with too much emphasis on specific examples I give. Sure, Earth being 1 million years old is unlikely, but there could be some equally embarrassing artifact or contradictory evidence. I can’t give a realistic example because I haven’t studied the problem—that’s my whole point. You seem to be saying that the Theory of Evolution is unfalsifiable, at least in practice. That would be a bad thing, not a good thing. Besides, surely, if someone runs cryptological analysis software on the DNA of E. Coli, and get back “(C) Microsoft Corp.”, that would rather undermine the theory?:)
In actuality, for me it comes down to trust: I expect if there was important contradictory evidence, someone would report it. Creationists think that biologists are all in on a conspiracy to hide the truth and would not change their mind if they see such evidence—that is rather unlikely from my point of view. That is to say, like you, I am not spending a lot of time evaluating the underlying facts because I think one side is reliable and the other is not. But it feels wrong to me to ignore evidence because of who says it. I understand your argument that you expect some evidence to be presented by them and that makes it unnecessary to examine it, but I think you are wrong. You do have to examine it in case it turns out that their evidence is in fact overwhelming your prior. They could be right in a specific case even if it’s unlikely. Even a stopped clock is right twice a day.
You seem to be saying that the Theory of Evolution is unfalsifiable, at least in practice. That would be a bad thing, not a good thing.
Let’s be a bit more precise. Evolution is a mechanism. It works given certain well-known preconditions. The fact that it works is not contested by anyone sane.
What actually is contested by creationists is that the mechanism of evolution is sufficient to generate all the variety of life we see on Earth and that it actually did, in fact, generate all that variety. *That* claim is falsifiable -- e.g. by showing that some cause/mechanism/agency other than evolution played an important part in the development of life on Earth.
You’re steelmanning the creationist position. That’s fine, but by saying “what actually is contested...” you’re also asserting that creationists only believe your steelman and not the position it’s a steelman of.
There may be some who do.
However, there are plenty of creationists who think that evolution cannot work. Some of their arguments include: “Evolution would mean order comes out of disorder, which is impossible” and “Evolution is a violation of the Second Law of Thermodynamics.”
I think it better be true that both of these are falsifiable (and they both are). I agree that the former is overwhelmingly likely and no one I’d care to talk to disputes it. In any event I am only talking about the latter. The fact that it completely explains the variety of life on Earth is the very thing I am accepting on faith, and that’s what I don’t like.
if cognitive biases/sociology provide a substantial portion of or even all of the explanation for creationists talking about irreducible organs, then their actual counterarguments are screened off by your prior knowledge of what causes them to deploy those counterarguments; you should be less inclined to consider their arguments than a random string generator that happened to output a sentence that reads as a counterargument against natural selection.
I’ve just discovered Argument Screens Off Authority by EY, so it seems I’ve got an authority on my side too:) You can’t eliminate an argument even if it’s presented by untrustworthy people.
What you are talking about is a lay sense of evolution. Sure, things change, and the more adapted thing should survive with higher frequency, this much is obvious even to creationists. It is also obvious to me (as it was to Aristotle), that things which are in motion tend to come to rest. Turns out, it’s not really true. Just because a theory is intuitive, doesn’t mean that’s how the world really works. You only need to think about Heliocentrism, let alone something like quantum physics.
One problem that Darwin had was the lack of mechanism for evolution (i.e. genetics). If I were alive at the time he wrote his books, I would have liked his theory, but would have been forced to acknowledge that it does not truly explain how the world works. I am told that now this is all solved, but have been taking that largely on faith.
It also may be that the theory is wrong, but there is no better theory to replace it, a la physics in 1900. If that were the case, I’d like to know that too.
We should expect some amount of evolution by natural selection ‘a priori’, from various obvious premises such as
(1) There is a reproduction process in which characteristics are inherited (2) Things with X characteristics in Y environment die/live etc.
There seems to be an absence of similarly parsimonious explanations, and the account given by natural selection is compelling. I suspect that even a small amount of knowledge of the empirical evidence for natural selection would establish a lower bound on the share of evolution it causes, such that searching for equally significant factors for evolution of life in general should be expected to fail.
If one set up a mathematical representation of a population that took into account characteristics, life, and death, etc. then natural selection would be the name for a provable behaviour of the system, even if the system were just axiomatised by more basic facts such as (1) and (2). I’m not convinced that the same is true of Aristotelian physics.
I struggle far more to fabricate accounts of our observations without natural selection than I did to get to grips with Newtonian mechanics. As in, accounts that don’t leave me more confused (e.g. ‘God did it’, which is a mysterious non-answer).
Quantum mechanics I do not know well enough (and I’m not sure anyone does) at the level where mathematical reductionism meets theoretical physics, but I would not be surprised if it turned out to be extremely parsimonious given even a small number of our empirical observations.
Heliocentrism also seems much more contingent than natural selection, although possibly less than one thinks, given how prevalent star-planet systems are.
This merely says that the surviving characteristics will move towards optimal in an unspecified range, assuming there are no other significant influences.
It is not explained how exactly the things with less likely characteristics have appeared in the first place. Is there perhaps another process that causes non-optimality? How could you know the process is not actually stronger than the process of natural selection?
It is also not obvious that this process of improvement can cross boundaries between species. You proved that a healthy dog is more likely to survive than a sick dog. You didn’t prove that the super-healthy dog will evolve to a lion or an eagle.
So this naive observation is actually not in contradiction with creationism. (Of course only after the creationism is updated to include it. But hey, scientists change their opinions, too.)
To move further, we need to know that the information which encodes the organism can change randomly (mutation), and that all species use the very same mechanism, so it is possible in theory to modify the information step by step starting with dog and ending with an eagle, in each step getting organisms which would be optimized for some environment. We need some kind of “universal DNA” hypothesis, even if we don’t know the exact formula for the DNA. And it’s not really obvious that dogs and eagles and fish and trees are all encoded in the same way.
On the other hand, once we have a microscope, the “universal DNA” hypothesis becomes rather simple to prove, because it is enough to explore what we have here and now.
I agree that understanding the extent to which natural selection generated things is easier nowadays than it was previously.
I’m not concerned here with logical disproofs of creationism, moreso with something like arguing that time spent {worrying that evolution by natural selection is significantly overrated} is probably misallocated, or arguing that people are privileging the question of ‘Is evolution by natural selection a good explanation?’ (I’m not entirely sure what my motivation is, but it feels like it’s at least partly something along those lines.)
I also think that there’s a lot of hard-to-enumerate background information available to a person nowadays that should be enough for a naturalistic reductionist to intuit that evolution will not arise from bolted-on complex mechanisms like creation, but rather from mechanisms like natural selection that are inherent to populations with a few basic properties that we have actually observed (e.g. finite lifespans that vary according to characteristic-environment interaction, inheritance of characteristics, etc.). It’s possible you understand this and I’m misinterpreting the point at which you’re challenging my argument, but I would very strongly disexpect somebody thinking like me along the lines of ‘provable properties of populations under observed axioms’ (or the probabilistic/continuous generalisation thereof) to be talking about creationism; rather, I would expect challenges to come in the form of other equally basic, low-complexity processes that arise from what we already know.
I’m not sure DNA/the exact method of inheritance is relevant; I would still consider it to be a win for natural selection if we had, say, Lamarckism/inheritance of acquired characteristics/epigenetics as a significant force.
Well, we have tons of observation that nature can be understood, and that the useful explanations do not involve gods or magic. So yes, it would be a reasonable prior expectation for the origins of species, too.
I agree that certainly some evolution would follow from your premises (1) and (2). But imagine that we also have independent evidence that Earth is 1 million years old. In that case, I’d be forced to say that the Theory of Evolution can’t account for the evidence of life we observe, given mutation rates, etc. This is the sort of thing I am worried about when I say I haven’t looked at the evidence. As far as I know there isn’t any contradictory evidence of this sort, but there may be specific challenges that aren’t well-explained. Creationists like to cite irreducible organs and claim that those exist (i.e. where it can’t evolve from anything that has any evolutionary advantage) and are contrary to the theory. I know about this objection, but it would be a lot of work to truly evaluate it in depth.
As far as having an alternative: this isn’t necessary. I’d be reluctant to go with “God did it”, so I’d be fine with “the theory explains 95% of the evidence, and about the other 5% we don’t know yet, and we have no better theory”.
Just realised you’re the post author, so: Thanks for posting this, it’s something I’ve wondered about in relation to myself, as well. :)
1: No tentacles
This reminds me of something Eliezer once said—”How would I explain the event of my left arm being replaced by a blue tentacle? The answer is that I wouldn’t. It isn’t going to happen.” We do not observe a young (even 10^6) Earth, and by suggesting the possibility of one as counterevidence against the strength of the ‘a priori’ reasoning I advocated, you must be smuggling in a circular assumption that young Earth models have significant probability.
Your argument as I understand it is roughly that since my a priori reasoning would fail in young Earth scenarios, then that reasoning is unreliable. But if our prior for young Earth scenarios is extremely low, then it will only very rarely happen that my reasoning will fail in that particular way. Therefore for your argument to go through, you would have to place a high prior probability on young Earth scenarios.
To put it another another way: If observing a young Earth would be evidence against my a priori reasoning, then by conservation of expected evidence, our actual observation of a non-young Earth must be evidence in favour of that reasoning.
People in a modern day situation, and LW’ers in particular, are better placed to understand that ‘naturalistic’ explanations are preferable, and that magic ones should incur huge complexity penalties. Therefore we should have low priors on young Earths, because most of our probability will be concentrated in models where intelligent life arises from nonintelligent (hence slow) processes as opposed to intelligent (e.g. God) processes.
Moreover, the more intelligent the process that generated us, the more we push the explanatory buck back onto that process. God is an extreme case where the mystery of the apparent improbability of human intelligence is replaced with the mystery of the apparent improbability of divine intelligence. But even less extreme cases like superhumanly (but still decidedly ‘finitely intelligent’) entities simulating us incurs a penalty for passing the explanatory buck back. Natural selection is so elegant and formidable because it is an existing behaviour of what we already observe.
2: Insanity screens off charity
If—even before accepting evolution by natural selection—you can put an extremely high probability on creationists spewing objections like ‘irreducible organs’ regardless of the veracity of evolution by natural selection, then you can pretty much write off the counterarguments of creationists, because your observation of creationists making these arguments is extremely weak evidence that there is anything to these counterarguments. Now, this is circular if your only reason for not taking creationists seriously is that they are wrong natural selection/irreducible organs, but there’s ‘any number’ of other reasons to suspect creationists are engaging in motivated cognition.
The same way that if natural selection provides a substantial portion of the explanation of evolution, then, you need look no further, if cognitive biases/sociology provide a substantial portion of or even all of the explanation for creationists talking about irreducible organs, then their actual counterarguments are screened off by your prior knowledge of what causes them to deploy those counterarguments; you should be less inclined to consider their arguments than a random string generator that happened to output a sentence that reads as a counterargument against natural selection.
I think you are interpreting my comments with too much emphasis on specific examples I give. Sure, Earth being 1 million years old is unlikely, but there could be some equally embarrassing artifact or contradictory evidence. I can’t give a realistic example because I haven’t studied the problem—that’s my whole point. You seem to be saying that the Theory of Evolution is unfalsifiable, at least in practice. That would be a bad thing, not a good thing. Besides, surely, if someone runs cryptological analysis software on the DNA of E. Coli, and get back “(C) Microsoft Corp.”, that would rather undermine the theory?:)
In actuality, for me it comes down to trust: I expect if there was important contradictory evidence, someone would report it. Creationists think that biologists are all in on a conspiracy to hide the truth and would not change their mind if they see such evidence—that is rather unlikely from my point of view. That is to say, like you, I am not spending a lot of time evaluating the underlying facts because I think one side is reliable and the other is not. But it feels wrong to me to ignore evidence because of who says it. I understand your argument that you expect some evidence to be presented by them and that makes it unnecessary to examine it, but I think you are wrong. You do have to examine it in case it turns out that their evidence is in fact overwhelming your prior. They could be right in a specific case even if it’s unlikely. Even a stopped clock is right twice a day.
Let’s be a bit more precise. Evolution is a mechanism. It works given certain well-known preconditions. The fact that it works is not contested by anyone sane.
What actually is contested by creationists is that the mechanism of evolution is sufficient to generate all the variety of life we see on Earth and that it actually did, in fact, generate all that variety. *That* claim is falsifiable -- e.g. by showing that some cause/mechanism/agency other than evolution played an important part in the development of life on Earth.
You’re steelmanning the creationist position. That’s fine, but by saying “what actually is contested...” you’re also asserting that creationists only believe your steelman and not the position it’s a steelman of.
There may be some who do.
However, there are plenty of creationists who think that evolution cannot work. Some of their arguments include: “Evolution would mean order comes out of disorder, which is impossible” and “Evolution is a violation of the Second Law of Thermodynamics.”
Sure, but we are not really talking about the creationists here, we’re talking about whether evolution is falsifiable and in which sense.
As the person who asked the question, I’d like to say that I don’t particularly care about what creationists believe either.
I think it better be true that both of these are falsifiable (and they both are). I agree that the former is overwhelmingly likely and no one I’d care to talk to disputes it. In any event I am only talking about the latter. The fact that it completely explains the variety of life on Earth is the very thing I am accepting on faith, and that’s what I don’t like.
I’ve just discovered Argument Screens Off Authority by EY, so it seems I’ve got an authority on my side too:) You can’t eliminate an argument even if it’s presented by untrustworthy people.
Argument screens off authority only if you have already considered the argument. This doesn’t mean you should consider all arguments by anyone.