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Comment by J_Thomas on Beautiful Math · 2008-01-11T23:37:25.000Z · LW · GW

Chris and Ben, we create axiom systems and we discover parts of "mathematics". There are probably only a finite number of theorems that can be stated with only 10 characters, or 20 characters, or 30 characters, provided we don't add new definitions. But the number of possible theorems quickly gets very very large. Will each independent group of mathematicians come up with the same theorems? Probably not. So we get different mathematics.

How different could alien mathematics be? I don't know. We could look at a variety of alien mathematics and see. Except, we don't have much of that. We presumably had different mathematical traditions in china, india, and europe, and we got some minor differences. But they were solving similar real-life problems and they could have been in communication. If you want trade in silk then you need a lot of it for it to make much difference. A very few mathematicians traveling could spread ideas easily.

It's easy to see alternate physics, and alternate technology is kind of arbitrary. I think alien math might be pretty different depending on which theorems they proved first. But I don't have good examples to demonstrate it.

The Pennyologist who notices the O's is not that different from the Pennyologist who notices there's one L on each side. A particular Pennyology might notice one of those, or the other one, or both. Out of the many relationships you could pick out from the penny, which ones will people pay attention to?

Comment by J_Thomas on 0 And 1 Are Not Probabilities · 2008-01-11T15:05:30.000Z · LW · GW

Usually, if a die lands on edge we say it was a spoiled throw and do it over. Similarly if a Dark Lord writes 37 on the face that lands on top, we complain that the Dark Lord is spoiling our game and we don't count it.

We count 6 possibilities for a 6-sided die, 5 possibilities for a 5-sided die, 2 possibilities for a 2-sided die, and if you have a die with just one face -- a spherical die -- what's the chance that face will come up?

I think it would be interesting to develop probability theory with no boundaries, with no 0 and 1. It works fine to do it the way it's done now, and the alternative might turn up something interesting too.

Comment by J_Thomas on Beautiful Math · 2008-01-11T14:00:33.000Z · LW · GW

"To say that human beings "invented numbers" - or invented the structure implicit in numbers - seems like claiming that Neil Armstrong hand-crafted the Moon. The universe existed before there were any sentient beings to observe it, which implies that physics preceded physicists."

No, there's a conflation of two things here.

Have you ever really looked at a penny? I'm looking at a 1990 penny now. I know that if you look at the front and you see the bas-relief of Lincoln, and the date 1990, and it's a penny, then you can be sure that the back side will have a picture of the Lincoln memorial. It works! And you can find all sorts of connections. Like, there's a single "O" on the front, in the name GOD in the phrase IN GOD WE TRUST. And there's a single "O" on the back, in the phrase ONE CENT. One O on the front, one O on the back. A connection! You could make lots and lots of these interconnections between the front and the back of the penny, and draw conclusions about what it means. You could invent a discipline of Pennyology if only somebody would fund it.

Is it true that Pennyology is implicit in pennies? In a way. Certainly the pennies should exist before the Pennyology. But the pennies are only whatever they are. The existence of pennies doesn't tell us much about what the practitioners of the discipline of Pennyology will actually notice. They might never pay attention to the pair of O's. There could be a fold in Lincoln's coat that after the proper analysis provides a solution to the whole world crisis, and they may never pick up on it. While it's predictable that different independent attempts at Pennyology would have a whole lot in common since after all they all need to be compatible with the same pennies, still they might be very different in some respects. You can't necessarily predict the Pennyology from looking at the penny. And you can't predict what mathematics people will invent from observing reality.

You can predict some things. A mathematics that invents the same 2D plane we use and that proves a 3-color theorem has something wrong with it. But you can't predict which things will be found first or, to some extent, which things will be found at all.

If there's a reality that mathematics must conform to, still each individual version of human mathematics is invented by humans.

Similarly with physics. Our physics is invented. The reality the physics describes is real. We can imagine a platonic-ideal physics that fit the reality completely, but we don't have an example of that to point at. So for example before Townsend invented the laser, a number of great physicists claimed it was impossible. Townsend got the idea because lasers could be described using Maxwell's equations. But people thought that quantum mechanics provided no way to get that result. it turned out they were wrong.

Actual physics is invented. Certainly incorrect physics must be invented. There's nothing in reality that shows you how to do physics wrong.

Comment by J_Thomas on A Failed Just-So Story · 2008-01-06T23:17:08.000Z · LW · GW

Robs, religions tend to thrive among people who work hard and behave well and such. The two tend to go together. But just as priests do well in that environment so do politicians. How can we tell whether these people are helping to maintain the prosperity, or merely parasitising it? In general parasites do better with healthy hosts.

I do not claim that religion is useless. I claim that you are assuming your conclusion that it is not. Ideally we might find some sort of data. We might for example look at examples where people who previously had no religion get proselytised into a religion and see how much better they get at working hard and behaving well and all that. To actually find out we should test our ideas against reality rather than just assuming that our beliefs are objectively true.

Comment by J_Thomas on A Failed Just-So Story · 2008-01-06T08:38:24.000Z · LW · GW

Razib, I see you argue that different religions can compete, and what they compete for is converts who perhaps are comparing the benefits the competing religions provide them. Whether individuals make rational choices or whether they irrationally gravitate to the religions that appear to bring prosperity, either way the religions compete.

But I'm talking about how religions could have gotten their start. If people who are predisposed to religion are better at living in larger-than-kinship groups, and if people who live in larger groups survive better, then the spread of predisposition-for-religion can be explained by individual selection without requiring group selection arguments.

Comment by J_Thomas on A Failed Just-So Story · 2008-01-05T13:44:15.000Z · LW · GW

Lots of people think that the main thing religions do is to bind people together. The etymology of the word works that way, right? re-ligio.

If they think that's what religion does, then it's only natural they'd think that's what it gets selected for. No mystery there.

Does it take group selection? People can stay in family groups with kin selection. No mystery. Suppose that people in groups all tend to survive better than loners. That's plausible. Then anything that helps people work together in larger groups (without too many side effects) could be individual-selected. Each individual is selected for the ability to join groups and the ability to maintain them, because the more time he spends alone or in a broken group, the worse his survival. Each individual is selected to correctly choose which others to throw out -- throw out good members sand the group is weakened. Fail to throw out members that will make the group collapse and each individual member is threatened.

It's only group selection when it's religious groups competing against nonreligious groups. It's individual selection when it's individuals in groups competing against loners.

Comment by J_Thomas on The Amazing Virgin Pregnancy · 2007-12-25T18:33:19.000Z · LW · GW

I didn't think it was tremendously funny. But I thought it was funny enough to recite the whole thing to my wife while she sat at her own keyboard, instead of just send her a link. She didn't think it was tremendously funny. But she politely stopped typing to listen, and she laughed some.

It seems to me like at least a B effort. The humor was in everybody wanting to believe.

In reality, wasn't there a claim that the midwife confirmed Mary was a virgin? If I lived in the village I'd probably accept that as sufficient evidence, though in my namesake's tradition I'd rather stick my own fingers in to confirm it.

For myself it's pretty much irrelevant. There was an ecumenical joke when I was a kid -- a preacher compared the different protestant faiths as being like different roads that could be taken to get your cotton to a cotton gin. And when you get there, the engineer isn't going to ask you "Which road did you take?" He's going to ask you, "How good is your cotton?".

By the same reasoning, when Jesus comes to me with a morality for me to follow, I don't ask him "What miracles did you have about your birth?". I ask him, "How good is your morality?".

Comment by J_Thomas on When None Dare Urge Restraint · 2007-12-09T13:06:00.000Z · LW · GW

"If you want to see an example of a measured response, take a look at the UK's after the London Underground bombings of 7th July 2005. Admittedly the bombings weren't of the same league as the September 11th attacks, but virtually nobody in the UK was saying "let's bomb the f*ers" And a month or two later (at the most) it was as if nothing had ever happened."

Mike K, I tend to agree with you, but....

The fact is, the british empire is gone and the british are ex-colonialists. As a nation they're old and tired and wimpy. It's different for us -- you can't be the world's only superpower and let anybody get away with anything. If we let one terrorist group have the WTC they'll all want one.

So as the winners of the cold war we have to respond to any provocation -- we have no choice. Any little group of terrorists can tell us who to invade and we have to do it, or we let the terrorists win. Either we kill off every terrorist group that isn't under our direction, or we lose our special status and have to admit we aren't in control of the world.

Think about it.

Comment by J_Thomas on When None Dare Urge Restraint · 2007-12-09T03:10:42.000Z · LW · GW

"If you believe invading Afghanistan was a correct choice then I'm not sure how you could say Iraq was a complete mistake. The invasion of Afghanistan was aimed at eliminating a state that offered aid and support to an enemy who would use that aid and support to project power to the US and harm her citizens or the citizens of other western states. Denying that aid and support would hope to achieve the purpose of reducing or eliminating the ability of the enemy to project power.

"Any other state that might offer aid and support to the enemy would enable the enemy to rebuild their ability to project power. Iraq was one possible source of aid and support."

Brandon, your reasoning is compelling. However, it has a subtle flaw that I think will be easier to see when I rephrase the argument as follow:

We will be safer after we conquer every potential enemy.

The claim is obviously true, and yet....

Comment by J_Thomas on When None Dare Urge Restraint · 2007-12-09T03:00:44.000Z · LW · GW

"I would have preferred, for example, that the U.S., Russia, China, UK, Israel and perhaps France announced that in one year they will declare war an any other nation that either has weapons of mass destruction or doesn't allow highly intrusive inspections to make sure they don't have weapons of mass destruction."

James D. Miller, I think your idea has possibilities. However, it would be very hard for it to succeed with israel on the list of nations that has nukes but denies them to others. Israel would have to be one of the nations that would be destroyed if it keeps nuclear weapons or refuses highly intrusive inspections.

What about india? Shouldn't they be on the list? We don't want war with india, they haven't threatened anybody except, well, pakistan.

And what about pakistan? If we let india keep nukes it would be hard to invade pakistan over their nukes. Should pakistan be one of the nations of the alliance that will destroy anybody else who has nukes?

Now it looks like a hard problem. No, your idea does not look workable. Allow russia to have nukes but not china? No. Allow china to have nukes but not india? Hardly. Allow india to have nukes but not pakistan? Tempting, but no. Allow pakistan to have nukes but not israel? It would be a good idea but it won't fly. Allow israel to have nukes but not syria? A pleasant thought but not practical. Allow israel and arab nations both to have nukes? Not practical either.

There's a logic here that hasn't played out yet. It goes:

  1. You don't need nukes unless you have enemies.
  2. If you get nukes, after awhile your enemies will too, and you can't stop this.
  3. If you and your enemies have nukes then you will be worse off than if neither you nor your enemies have nukes.

Therefore:

  1. Don't get nukes.

The world as a whole hasn't recognised this logic yet because there haven't been any graphic examples. Probably after the second nuclear war, when the world sees what happens to the "winner", people will have a much clearer idea about it. But two nuclear wars will be hard on the world. Ideally these wars would involve small countries so they can be small nuclear wars.

So most of us will be better off if lebanon gets nukes. Then a nuclear war between lebanon and israel could be one of the smallest possible nuclear wars.

The next obvious choice is a war between libya and chad.

After 2 nuclear wars the world as a whole will be much more ready for disarmament then they are now, with nuclear war a threat that has not materialised for 62 years.

Ir'a much much easier to stop people from doing something they didn't want to do in the first place, than stop them from something they think can keep you from dominating them.

Comment by J_Thomas on When None Dare Urge Restraint · 2007-12-09T02:17:02.000Z · LW · GW

"I'd say they were cowards. Suicide isn't an act of bravery."

R U Kidding, I agree in this particular case.

If they had lived, we would have caught them and slowly tortured them to death. They were taking the easy way out by dying. Similarly with palestinian suicide bombers. By dying they avoid the treatment they'd get as prisoners of the israelis -- they get off easy.

"I still remember a kid who hit me from behind on the street once, because he was too much of a pussy to come up to my face about it."

He was expressing his feelings. Did he tell you he was too scared to face you? You might have misunderstood his intentions. At any rate, modern war often involves a surprise attack. When your intention is that the other guy wind up dead and you wind up alive, why give him any advantages? Neither the USAF nor the israeli air force typically announce their airstrikes ahead of time.

If the kid you remember had intended to kill you, it would make perfect sense for him to attack you from behind and kill you as quickly as he could, rather than give you anything like an even chance to kill him instead. But he bravely left you alive to respond however you chose to. If he had killed you properly you wouldn't have found out who did it before you died. You owe your life to his courage.

"But to those who can't comprehend the possibility that the so-called overreaction might have saved lives, consider that Al Quaeda was escalating attacks until it got the desired response: war. And what, pray tell, do you think the next level of escalation would be, that would one-up the thousands killed on 9/11? Nuclear terrorism, maybe. Biological terrorism."

AQ had a number of guys trained as infantrymen, and about 10% as many trained for espionage. We rolled up their spies and saboteurs real fast. We maybe got a bunch of innocent arab-americans at the same time, but we got most of the ones we were looking for.

When we invaded afghanistan we got a lot of the infantry guys too. They could possibly have been a threat to saudi arabia -- trained dedicated infantry fighting saudis and mercenaries might have done a lot of damage -- so that's maybe a plus. There's no particular reason to think AQ could have "escalated" after our police and counterintelligence guys hit them. The army thing was more for US public relations than anything else -- the public wanted a war so the US government gave them one. We gave AQ what they wanted, against most strategic sense, because they persuaded the US public to want what AQ wanted, and Bush also saw the chance to gain US public approval.

I think. I can't be entirely sure what Bush was thinking. I assume he was rationally looking at his own advantage, but he may not have been thinking at all.

"You're letting your hatred of Bush prejudice your interpretation of events."

Well, no. My disgust at Bush came from the events. Not so much the other way round.

Comment by J_Thomas on Uncritical Supercriticality · 2007-12-06T15:45:46.000Z · LW · GW

"But there is never an Idea so true that it's wrong to criticize any argument that supports it. Never. Never ever never for ever."

Was it wrong for the guy who thought Buzz Aldrin helped fake the moon landing to present his arguments to Buzz?

One of the hungarian Manhattan-project physicists had a slogan that went "It is not enough to be rude, one must also be wrong." When it comes time to decide whether to answer a verbal argument with violence, does it matter whether the argument is wrong, or is it enough to be rude?

Comment by J_Thomas on Uncritical Supercriticality · 2007-12-05T21:39:26.000Z · LW · GW

GW, to what extent should we treat people as we want them to treat us, and to what extent should we treat them the way they say is right and the way they treat others?

Sometimes it's polite to treat other people by their own standards, and it isn't an admission that their way is right and ours is wrong.

Comment by J_Thomas on Uncritical Supercriticality · 2007-12-05T21:07:05.000Z · LW · GW

So don't tell me about situations in which it is appropriate to respond to an argument with violence. Tell me about realistically obtainable states of belief in which it is appropriate to respond to an argument with violence.

I don't exactly agree with this, but I can see it as a social signal. As Buzz Aldrin and John Barnes seem to express it, when somebody makes his argument that you utterly despise, you hit him to show that you refuse to engage in rational argument with him. He is your enemy and beyond the pale and his position is not one that you consider open to rational debate.

So for example a zionist might respond this way to someone who argues that israel/palestine should become one democratic nation under one-person/one-vote. It would mean the destruction of the state of israel, it would mean that israelis would become a minority in their own country. A zionist could respond with words, something like "I don't need logical arguments for why israel should exist. Israel exists because people like me are ready and willing to kill anybody who tries to destroy her.". But a good swift sock in the jaw says the same thing more forcefully, without actually killing anybody. Ideally you knock him out and he falls down and hits his head on the floor, and when he wakes up he will be a chastened antisemite, a subdued antisemite, a far more submissive antisemite. He will not annoy you with logical argument.

Similar treatment might be effective against communists, pro-abortionists, and liberals generally. Logical argument can only carry you so far; at some point you get to principles that you accept because of who you are. You can't expect everyone to accept those same principles because they are not you. Some people accept the principle "You should not sock somebody in the jaw just because he disagrees with you" and some do not.

How we get along in social conversation with people who disagree with us says a lot about us. If you're having a civil conversation with a rapist, or a serial killer, or a republican, how do you handle yourself? Should you always wait for him to strike the first blow, or is it ever appropriate to cold-cock him with no warning?

Comment by J_Thomas on Uncritical Supercriticality · 2007-12-05T06:58:58.000Z · LW · GW

in the human art of rationality there's a flat law against meeting arguments with violence, anywhere in the human world

"No. You're confusing rationality with your own received ethical value system. Violence is both an appropriate and frequently necessary response to all sorts of arguments."

I want to note that Buzz Aldrin, the second man to set foot on the moon, famously encountered a man who denied that humans have ever gone to the moon but that the videos of Buzz on the moon were filmed in arizona. Buzz's response when the man presented his arguments was to sock him in the jaw.

The science fiction writer John Barnes, who collaborated with Aldrin on a couple of science fiction novels, has since written several novels in which the appealing protagonist argues that the only appropriate response to some arguments is a good swift sock in the jaw. His protagonists do so, with good results.

Millions of impressionable young science fiction readers are influenced by these novels.

If you met John Barnes and he argued that he's doing the right thing, would it be appropriate to sock him in the jaw?

Barnes is 53 years old but has been doing martial arts for something like 30 years. Would that influence your choice?

Should you let the moral value of initiating violence depend on whether or not you win?

If it's right to physically attack somebody who disagrees with you provided you win but wrong when you lose, what about when it's a ten year old girl who makes an argument you can't answer except with violence?

Comment by J_Thomas on The Hidden Complexity of Wishes · 2007-11-24T15:15:13.000Z · LW · GW

This generalises. Since you don't know everything, anything you do might wind up being counterproductive.

Like, I once knew a group of young merchants who wanted their shopping district revitalised. They worked at it and got their share of federal money that was assigned to their city, and they got the lighting improved, and the landscaping, and a beautiful fountain, and so on. It took several years and most of the improvements came in the third year. Then their landlords all raised the rents and they had to move out.

That one was predictable in hindsight, but I didn't predict it. There could always be things like that.

When anything you do could backfire, are you better off to stay in bed? No, the advantages of that are obvious but it's also obvious you can't make a living that way.

You have to make your choices and take your chances. If I had an outcome pump and my mother was trapped in a burning building and I had no other way to get her out, I hope I'd use it. The result might be worse than letting her burn to death but at least there would be a chance for a good outcome. If I can just get it to remove some of the bad outcomes the result may be an improvement.

Comment by J_Thomas on Conjuring An Evolution To Serve You · 2007-11-19T15:11:25.000Z · LW · GW

Skilling was selecting badly. The 10% he discarded each year might have included some he should have kept, and vice versa.

Similarly, God at one point said he was going to get rid of evil people and keep good people and so people would get better. I don't see much evidence that's worked well.

Evolution happens, but if you want to harness it for your own goals you have to be very careful. Try to arrange it so you can throw away your mistakes.

Comment by J_Thomas on Conjuring An Evolution To Serve You · 2007-11-19T13:02:03.000Z · LW · GW

There are lots of examples of unexpected selective outcomes.

A story -- a long time agon a swedish researcher tried to increase wheat yields by picking the biggest wheat kernels to plant. In only 5 generations he had a strain of wheat that produced 6 giant wheat kernels per stalk.

When scale insects were damaging citrus fruits, farmers tried to poison them with cyanide. They'd put a giant tent over the whole tree and pump in the cyanide and kill the scale insects. Plants can be immune to cyanide but no animal that depends on respiration can be. And yet in only 5 years or so they got resistant scale insects. The resistant insects would -- when anything startling happen -- sit very still and hold their breath for half an hour or so.

If you want to do directed evolution, you do better to do it in controlled conditions. Take your results and test them carefully and make sure they're what you want before you release them. Microbiologists who want mutants for research commonly take 20 or 100 mutants who survive the conditions they're selected to survive, and test until they get a few that appear to be just what they want. Eliminate the rest.

So, for example, to find a mutant that has a high mutation rate -- start with a strain of bacteria that has at least 4 selectable traits. Say, they don't survive without threonine, don't survive without isoleucine/valine, don't survive penicillin, and don't survive rifampicin. So you grow up a hundred billion or so of them and then you centrifuge them down and resuspend them in medium that doesn't have threonine. Most of them die. Wait for the survivors to grow, and then centrifuge them down and resuspend them in medium that doesn't have isoleucine/valine. Most of them die. Wait for the survivors to grow, and centrifuge them down and resuspend them in medium that has penicillin. Do it a fourth time with rifampicin. Plate them out on media that has lactose (when the originals couldn't use lactose). Some of the colonies will be large and some small, pick a colony that has lots of little warts of bigger growth, because it gets lactose-using mutants even while the colony is growing. A strain that has a hundred times the mutation rate can be easily selected this way. It started out at frequency around 10^-8. After the first selection cycle it was frequency around 10^-6. By the fourth round it was common. Sometimes you can get a mutation rate around 1000 times the normal rate. Much above that and it doesn't survive well.

Take one colony per try because you don't want to test multiple colonies and then find out they're the same mutation over again.

Comment by J_Thomas on Terminal Values and Instrumental Values · 2007-11-17T04:13:21.000Z · LW · GW

Me: "in principle you ought to consider the entire state of the future universe when you set a terminal value."

Douglas: 'Yes, and in practice we don't. But as I look further into the future to see the consequences of my terminal value(s), that's when the trouble begins.'

Me: Doctor, it hurts when I do this.

Doctor: Then don't do that.

Comment by J_Thomas on Evolving to Extinction · 2007-11-17T00:34:50.000Z · LW · GW

'Our modern transportation systems have effectively eliminated most of the barriers between human populations. All of our eggs are in one basket. If a highly lethal virus that will spread throughout an entire population and kill it arises, that basket will be dropped.'

This is a strong argument to change that situation. We have a communications system that lets us transmit data widely without needing personal contact. We could do some sorts of trade without a whole lot of risk, and minimise both the risk and the amount of trade for the rest.

It would be hard to do that effectively without a consensus among most of the world population, since people are so good at sneaking. So ideally over the next generation or so we'll develop a convincing case for dividing the world up into small breeding groups with strictly limited contact among groups, assuming the case actually is convincing.

At the moment the idea seems almost fantastical, as if we'd never put up with something like that. So we have a long way to go.

Comment by J_Thomas on Evolving to Extinction · 2007-11-17T00:24:55.000Z · LW · GW

"Doesn't this count as a case of group level selection?"

Yes, when it works. Divide the population into smaller groups with strictly limited breeding between groups, and that's one way that segregation distorters can be limited.

Better mechanisms might arise too, but until they do this is what you've got. There might be some other advantages to a population divided into small groups with limited interbreeding, too.

And once you have a population divided that way, it leaves the possibility for other group selection. However, rats are mammals, and mammals are a small minority group that are unimportant in the bigger scheme of things. How often are species divided up like that?

Comment by J_Thomas on Evolving to Extinction · 2007-11-17T00:11:14.000Z · LW · GW

'I would still be loath to call it "evolved to death". Where is the "evolution"?'

It happens because of a change in gene frequencies. That's what evolution is defined as -- changes in gene frequency. The mutant allele spreads and takes over. The population dies, but that doesn't keep the mutant allele from taking over among survivors while there are survivors.

Someone said the mutant allele isn't competing with X chromosomes. It's competing with both X and Y alleles. The mice start out with on average 3 X alleles per Y allele. At the end it's 1 X allele per mutant Y allele.

'Too bad, so sad. If there was an "evolution fairy", she would have designed a better machinery of genes.'

There may be a better machinery sometimes. The examples we have of segregation distorters may be examples where the better mechanism has broken down.

In the absence of better mechanisms, this sort of thing can happen. It's possible to get mutations which are selected and which spread even though in the long run they are bad for the population as a whole.

Analogously it's possible to make a lot of money in a free enterprise system while benefitting nobody but yourself, barring mechanisms to prevent that -- the "invisible hand" doesn't necessarily work to do what Adam Smith said it can do.

Comment by J_Thomas on Fake Selfishness · 2007-11-15T13:01:32.000Z · LW · GW

Mark, altruists have to deal with their costs too.

It's possible for an altruist to value the thousandth altruistic meal as much as the first, but as his resources shrink the value of the alternatives rises. If I provide meals for a hundred thousand starving people and then I have nothing left and I become a starving person myself, that isn't good. At some point I want to keep enough capital to maintain my continuing ability to feed starving people.

I'm not claiming that it's true that no altruist experiences diminishing returns, or even that there is an altruist who doesn't experience diminishing returns. But the behavior doesn't prove that there couldn't be, and so this isn't a killing blow.

Comment by J_Thomas on Terminal Values and Instrumental Values · 2007-11-15T11:20:15.000Z · LW · GW

Douglas, in principle you ought to consider the entire state of the future universe when you set a terminal value. "I want my sister not to be killed in the next few weeks by flesh-eating bacteria" is a vague goal. "My sister not being killed by flesh-eating bacteria because the world fell into a black hole and tidal effects killed her" is not an adequate alternative.

In practice we set terminal values as if they're independent of everything else. I assume that giving my sister penicillin will not have any side effects I haven't considered. As far as I know she isn't allergic to penicillin. If it will bankrupt me then that's something I will consider. I assume the drug company is not sending its profits to support al qaeda unless somebody comes out and claims it is and the mass media take the claim seriously. I assume the drug company won't use my money to lobby for things I'd disapprove of. I completely ignore the fact that my sister's kidneys will remove the penicillin and she'll repeatedly dose her toilet with a dilute penicillin solution that will encourage the spread of penicillin-resistant bacteria. If I did think about that I might want her to save her urine so it could be treated to destroy the penicillin before it's thrown away.

In practice people think about what they want, and they think about important side effects they have learned to consider, and that's all. If we actually had a holistic view of things we would be very different people.

Comment by J_Thomas on Thou Art Godshatter · 2007-11-15T02:52:05.000Z · LW · GW

Brendon, I find your reasoning plausible. I don't know how true it is. I don't want to give myself pernicious anemia to test it, so I'll settle for saying it looks plausible.

If you have a vitamin deficiency, and you get a dose of the vitamin that makes you somewhat less deficient, will you feel better within a few hours? If so then it might be reinforced. On the other hand, one single experience of nerve poisoning a few hours after eating a particular new food can be enough to establish a lifelong distaste for that food.

Comment by J_Thomas on Thou Art Godshatter · 2007-11-14T20:56:49.000Z · LW · GW

Brendon, you can't expect a learning system to quickly get an exact solution to a problem in N simultaneous equations. But when improvements result in a sense of well-being, they might tend to gradually zero in on solutions. So for nutrition you need sufficient energy and your body might have pre-programmed goals for repair and growth, and whatever helps meet those targets could provide that sense of well-being that announces something worked.

Simpler than having thousands of individual goals programmed in.

Comment by J_Thomas on Thou Art Godshatter · 2007-11-14T12:53:08.000Z · LW · GW

Just as an aside, fitness maximizers usually have to accept a finite population size in a finite biome with a finite carrying capacity. There's the possible goal of expanding into the galaxy and neighboring galaxies, but in the short run we have a finite carrying capacity.

And a fitness maximizer that is too successful has to accept it needs to preserve a lot of diversity in its gene pool or else face problems that would essentially reduce carrying capacity.

A conscious fitness maximizer at some point must realise that it survives by maintaining its numbers in a diverse population, rather than maximizing the frequency of its genes.

Comment by J_Thomas on An Alien God · 2007-11-14T12:15:47.000Z · LW · GW

Douglas, your ideas are reasonable but unproven.

It certainly makes sense that new proteins with new functions should arise by recombination among old proteins with old functions. Start with functional groups that do things -- hold a calcium ion, hold a magnesium ion, fit to a lactam group, etc -- and fit them together in just the geometry that gets a result, and then fiddle with the details to change that geometry slightly. Sure, that makes sense.

And to get brand new protein structures you need to evolve them special -- to get selected starting with a protein that has a different structure you need to go through intermediate stages that are likely to have no function at all. But if the protein is under selection that won't happen, and if there's no selection it's sill quite unlikely.

So it's plausible there should be some mechanism to do all that.

However, the trouble here is that this mechanism would have to be mostly inactive. Do we create novel new proteins every generation? Every hundred generations? Not as far as I know. What maintains this mechanism that produces a good result in one individual per thousand generations (maybe), and produces no result or bad results the rest of the time? It would have to be a side effect of something else, something that does get used a lot. And that may be possible, but would you expect it to be the same mechanism in prokaryotes and eucaryotes? We haven't observed it yet in that case. So two different mechanisms, like they have vastly different ways to have sex.... And we still haven't particularly found those mechanisms.

I don't regard your tuberculosis story as useful. OK, lots of things are preadapted toward making certain discoveries. But not other discoveries.

Sure, it isn't random. But the assumption of randomness was a mathematical convenience. Mutation shouldn't be random, There's been 3 billion years of selection to encourage mutation at the times and places it does the most good -- to the extent that organisms can predict that.

There's a lot about the way populations respond to natural selection that isn't known yet, there are exciting discoveries waiting for us. You and I both have hints about what those discoveries will look like. But the discoveries haven't been made yet and we're only guessing about them at this point. I can guess pretty well about some genetic mechanisms that would increase the rate of evolution, but I can't guarantee that nature hasn't found even better mechanisms that outcompete the ones I imagine.

Comment by J_Thomas on Protein Reinforcement and DNA Consequentialism · 2007-11-14T04:05:16.000Z · LW · GW

Billswift, after thinking it over some I'm surprised how much one person could do, if they knew not to follow any blind alleys. Like, you could do all the experiments needed to support Maxwell's equations in a reasonably short time if someone helped you set up the equipment.

It took a lot of people a long time to do it, but that's because they didn't know what they were doing ahead of time.

I don't know where the limits would come but they might be a lot broader than I first thought.

Comment by J_Thomas on Thou Art Godshatter · 2007-11-14T03:56:44.000Z · LW · GW

"I doubt a person who now found themselves in this situation would develop this revulsion."

By about the second generation a lot would. They would mostly be descended from people who hadn't used them. There is a minority that has a revulsion for condoms now. The idea of giving up practically your only change to have children, deliberately, would start seeming strange when everybody in the world had parents who hadn't done it. Cultures change faster when that happens.

Comment by J_Thomas on Thou Art Godshatter · 2007-11-14T00:42:51.000Z · LW · GW

We have no instinctive revulsion of condoms or oral sex. Our brains, those supreme reproductive organs, don't perform a check for reproductive efficacy before granting us sexual pleasure.

If we could barely arrange to have enough sex to cause 2 pregnancies per lifetime, then we would have a revulsion of condoms, oral sex, etc.

If for example we spent almost all of each year alone, and once a year men and women would meet on a sandy beach (or just offshore) and have sex, and that would be the only chance for women to get +regnant until the next year, men would compete intensely for the women who seem to be fertile, and the losers and the apparently-infertile women could console each other. When you only get one chance you don't waste it.

But humans use sex for social signalling. A man who publicly explained that he intended never to have sex except when he was trying to cause a pregnancy, might find himself at a disadvantage among some women.

But human brains clearly can imagine these links in protein. So when the Evolution Fairy made humans, why did It bother with any motivation except inclusive genetic fitness?

How are we supposed to tell? Like, we need food for energy and for building materials. When you don't get enough energy you feel that. When you don't get enough of some building material you feel that too, and you might learn to recognise that particular feeling. I've read about africans who specificly get hungry for meat, who identify the specific feeling of protein deficiency. How many others are there? Each individual amino acid? Each individual vitamin? I think instead you get rewarded by the feeling you get when there's enough of everything and no glut of something that causes problems. And it's up to your behavioral reinforcement system to notice foods that give you that feeling.

So humans love the taste of sugar and fat, and we love our sons and daughters. We seek social status, and sex. We sing and dance and play. We learn for the love of learning.

There maybe wasn't much chance to overdose on sugar or far in the old days. Or salt, if you were inland. Give it a few more generations and we might do that sort of thing less. Are Pima amerindians more susceptible to the amount of sugar we eat, or do they eat more because they can? I expect that's been tested but I don't know the answer myself. Maybe they haven't been exposed to sugar for as long, so they don't have the defenses against it we do.

You can learn strategies to play chess. Wouldn't it be nice if evolution had provided us with a chess-fitness optimiser? Instead of thinking about strategies, you just make the right move. But that requires the problem of winning at chess to be already solved.

It might very well turn out that in our future people who successfully reproduce will tend to be people who want to, and who figure out how to. There's some of that now, asnd maybe those people wind up with fitter children than the ones who become parents through carelessness. That might be hard to measure just now. Maybe the big majority of the children come from parents who give little thought to how they'll take care of their children, and the ones who're cautious wind up under-reproducing as a result. In the long run the evolutionary process will note what's worked whether we manage to measure it or not.

Comment by J_Thomas on Protein Reinforcement and DNA Consequentialism · 2007-11-13T12:06:00.000Z · LW · GW

"If we want to know how objects fall, though, we shouldn't ask people with the socially-awarded status of authority, we should look at falling things - like bricks."

But now we don't do much of that, we read physics books and work out the homework. There isn't time to repeat all the experiments. When it comes to supercolliders etc it would take years to work out the math and deal with the confounding variables and such.

Comment by J_Thomas on Burch's Law · 2007-11-13T02:58:39.000Z · LW · GW

xoc, the names of commenters are at the bottom of their comments, not the top. The commenter you were responding to was actually Buzzcut, not Eliezer.

Buzzcut, if you pay more for water than you do for gasoline, I want to suggest you find a cheaper source for your water. I can buy certified water in gallon jugs for not much over $1/gallon, but gasoline here is $3/gallon. I can get water cheaper in larger quantities, and I could buy a cheaper brand but then I find myself wondering about the certification. Kind of like buying the cheapest gasoline....

Comment by J_Thomas on Protein Reinforcement and DNA Consequentialism · 2007-11-13T02:41:14.000Z · LW · GW

Reinforcement learning isn't trivial, but it might be kind of modular. Evolution doesn't have to create reinforcement learning from scratch every time, it can re-use the existing structures and just hook in new inputs.

Learning takes a lot of overhead. Much less overhead if you can simply be born knowing what you need to know, instinctively. Konrad Lorenz believed that instincts somehow develop out of learned behavior. He looked at related species where one had an instinctual behavior and the other had to learn the same behavior. It takes so long to learn instincts by mutation and selection, it's intuitively obvious that learning should come first and then be replaced by instinct over time. But Lorenz didn't propose a mechanism for that to happen and I don't know a mechanism either.

We do so much less instinct than other animals that I'm tempted to think we haven't spent much time in consistent predictable environments. Maybe we've always lived by disrupting ecosystems and surviving in the chaos -- a role we would manage better than animals that do less flexible thinking.

Comment by J_Thomas on Adaptation-Executers, not Fitness-Maximizers · 2007-11-11T17:23:04.000Z · LW · GW

A long time ago I read a newspaper article which claimed that a Harvard psychological research project had women chew up chocolate and spit it out, while looking in a mirror and connected to some sort of electrodes. They claimed that after that the women didn't like chocolate much.

I tried it without the electrodes. I got a 2 pound bag of M&Ms. I usually didn't buy M&Ms because no matter how many I got they'd be gone in a couple of days. I started chewing them and spitting them out. Every now and then I'd rinse out my mouth with water and the flavor would be much more intense after that. I got all the wonderful taste of the M&Ms but I didn't swallow.

I did that for 15 minutes a day for 3 days. After that I didn't much like chocolate, and it took more than a year before I gradually started eating it again.

I think the esthetic pleasure of chocolate must have a strong digestive component.

Comment by J_Thomas on Beware of Stephen J. Gould · 2007-11-11T00:48:36.000Z · LW · GW

I first read about adaptive radiation in 1965 or so, I believe it was in Ralph Buchbaum's Basic Ecology. Or maybe it was World Book encyclopedia. It said that we get lots of speciation events right after a big extinction event, and then they slow down for a long time. You say that this is a special case. Because somebody hypothesised that it had something to do with genetic drift, while nobody hypothesised that PE had anything to do with genetic drift?

There is nothing you have described about PE that isn't true about adaptive radiation. Can you say what's special about PE? The fossil record already showed us that we got long periods of stasis in hard-parts, that was not a new observation. Did Gould perhaps suggest a new reason for the stasis, one that the population ecologists hadn't already stated?

I could easily be wrong that there's nothing here that's important and new. But you have said nothing to show what that something might be, or why it's important. If it's one of the fundamentally important things, why can't you say simply what's new and important about it?

Is it actually such a complicated idea that you can't explain the fundamentals in a short post?

Comment by J_Thomas on Beware of Stephen J. Gould · 2007-11-10T21:43:07.000Z · LW · GW

"A definition? That a substantial amount of speciation occurred during (geologically) relatively short periods of time, between which were long periods of relative stasis without actual speciation, although gradual changes were always occurring."

Mr. Rosser, This definition is very much like that in Wikipedia, true. As stated, it follows directly from observed adaptive radiation -- which has had explanations involving genetic drift. There is nothing new in this definition. It is not a new observation. Tnere is no new idea expressed here beyond the old observation. This is a pretty shiny packaged christmas present with nothing in it.

Can you state a definition that shows what's special about punctuated equilibrium? If you can't, then there's no reason to think you understand it.

I looked at your economics homepage. I think you're studying a fascinating specialty and I wouldn't be at all surprised if I learn interesting and useful things as I read your publications. Thank you for the link.

Comment by J_Thomas on The Tragedy of Group Selectionism · 2007-11-10T20:51:14.000Z · LW · GW

'Would "innovation" in genetic error correction, or changes to the proteins responsible for allowing greater or fewer mutations in DNA...'

'...would such "meta-changes" (changes to the mechanisms of DNA replication) be the basis for group selection?'

If they can't interbreed, then you get selection like that between two different clones of bacteria. Either the better species survives, or they both survive in their own ecological niches.

If they can interbreed then you might get evolution by group selection but it isn't the way to bet. You'd want a specific case for a particular gene.

'If not this, how did "innovations" to DNA error correction and selection for the different rules about how many mutations to allow in DNA copying even form in the first place?'

Given alternative genes that result in alternative behaviors (either from different enzymes or different regulation of those enzymes or something else) -- the one that works better results in its individuals outcompeting other individuals. That's what natural selection involves. The way you know it's fitter is that the gene frequency increases. We hope that on average things that increase gene frequency also improve survival of the individuals that carry them, and improve survival of the population. But there are examples otherwise.

Sometimes genes can increase because of selection among groups. This can happen but it's a complication that tends not to happen.

How does a mutation in a gene for mutation rate get changed in a population? When it starts out it's outnumbered a hundred million to one. The first favorable mutation that happens will almost certainly be among one of those hundred million and not in the single mutant.

And further, given mutations that are all about as good, the first one to get established gets the lion's share of the results. However, in a large population the mutation that makes a better mutation rate will happen occasionally in individuals that have a favorable mutation, and will spread with them. In the absence of selection against it, it will reach a fluctuating equilibrium for that reason. And this subpopulation will mutate at a better rate, and the result is that it will increase some with each population changeover. With each changeover the better mutation-rate mutants will tend to increase at the expense of the worse mutation-rate variants. Slow but reasonably sure, given a large population.

It's possible for genes to evolve that regulate things like mutation rate. They might increase the rate or decrease it according to whatever cues seem to work well on average. Selection can work to let populations evolve faster, and it's selection on indvidual genes (or combinations of genes) that does it.

It's possible to get genes that improve the survival of groups. But unless they spread they have limited chance to improve group survival.

Comment by J_Thomas on Beware of Stephen J. Gould · 2007-11-10T19:54:31.000Z · LW · GW

Barkley, you have given us no idea what idea it is you say is so important.

Is your claim that what it means is that there are some times when evolution of bony parts is fast, and other times when it is slow? That follows directly from "adaptive radiation", which has been known for a very long time and which suggests a reason. Nothing new there.

If it's such an important idea surely you can tell us what it means. Take all the time you want. Don't worry about it scrolling off, we'll wait for you.

At this point the argument isn't whether PE is important. The question is whether you know what it says. We can talk about how important it is after you show us you know what it means.

Comment by J_Thomas on Beware of Stephen J. Gould · 2007-11-10T13:05:30.000Z · LW · GW

Douglas, I don't claim that Gould's theory was wrong or unimportant. I claim that Gould's theory was incoherent to the point that there's no way to tell whether it was wrong or unimportant.

It's like deciding whether a horoscope or a Rorschach test is wrong or unimportant.

Eldredge's theory of Punctuated Equilibrium was unimportant. Eldredge explained it well enough to see what he was saying. Gould apparently was talking about something else.

Comment by J_Thomas on Beware of Stephen J. Gould · 2007-11-10T07:39:25.000Z · LW · GW

"A definition? That a substantial amount of speciation occurred during (geologically) relatively short periods of time, between which were long periods of relative stasis without actual speciation, although gradual changes were always occurring."

That's it? But we've known about adaptive radiation for a very long time. What's the new idea here, beyond this obvious observation?

I didn't quote those three to say they were important new ideas, I quoted them to give an idea what sort of explanation I'd accept. Reasonably short, showing what it was about, leaving out caveats and exceptions etc.

You haven't begun to show what Punctuated Equilibrium was about. I don't think it can be explained simply because there isn't a central new idea there.

Comment by J_Thomas on Beware of Stephen J. Gould · 2007-11-09T23:07:41.000Z · LW · GW

It's vitally important when spreading a new scientific idea to come up with a catchy name for it. "Punctuated equilibrium" was very good. However, the idea behind the name was very very fuzzy. It was a grab-bag of ideas, that never quite fit together. Where did the "hopeful monster"s fit in? It turns out they didn't. Punctuated equilibrium did not make sense in any unified way though a collection of disparate ideas were supposed to be it.

I finally found the concepts expressed clearly in a book by Eldredge. All the various obvious explanations were included. There was nothing mystical. There was nothing new. Standard population ecology concepts fit the whole thing. Unless of course Gould was describing other things that Eldredge didn't consider.

The spandrels concept was like something Eliezer might come up with. A fine name for a simple concept about how people sometimes misunderstand things. The "trait" that you notice may be a side-effect of what's selected. It's worth reminding beginners about that and worth remembering. It isn't more special than the average of Eliezer's hundreds of bias ideas.

Gould talked as if he had something that standard science did not explain easily. He was misleading. No hopeful monsters were needed. Everything he described was implied directly from standard approaches. Gould mostly did not describe solutions to his conundrums -- I think because if he had, he would have made it obvious that he was not actually posing any problems to be solved.

"I have yet to see anybody here offer up even one, much less ten, new ideas in evolutionary theory more important than Gould's of punctuated equilibrium."

Can you describe just what the dea is? When people ask for a description of Gause's Law or Weber's law or Fisher's Fundamental Theorem etc you could say pretty clearly what the idea is, right?

Gause's Law: No two species living in the same environment will live quite the same way. They will tend to differ in ways that are critical to their survival, because if they were in direct head-to-head competition for the same limiting factor one of them would tend to win and the other would go extinct. (It follows that two species that too much share the same critical limiting factor will tend to evolve in separate directions to reduce the overlap. They will evolve toward different ecological niches.)

Weber's Law: Animal senses distinguish differences, and the differences they can distinguish tend to be some fraction of the size of the stimulus. So if you can tell a 1% difference in how bright a light is when it's very dim, you can likely tell a 1% difference in brightness when the light is very bright also. If you can tell a 1% difference in sound volume for faint sounds it's likely to be around 1% for loud sounds too. This all happens within limits and it doesn't always work, but it's the way to bet.

Fisher's Fundamental Theorem: The rate of natural selection is directly proportional to the variance in fitness within the populatoin. This follows directly from the usual definitions of fitness and natural selection. If all individuals are just as fit then there's no selection, if there's a big difference in fitness then the less-fit are removed faster than with a small difference.

Can you describe what Punctuated equilibrium says? Perhaps the 2nd-most important new idea in evolutionary theory, can you describe the idea clearly?

Comment by J_Thomas on Natural Selection's Speed Limit and Complexity Bound · 2007-11-05T18:06:05.000Z · LW · GW

"Now with DNA, the mutation rate is fixed at ~10^-8."

Well no, it isn't. Not to get too complicated, usually the mutation rate is lower than that, but occasionally things happen that bring the mutation rate rather higher. We have things like DNA repair mechanisms that are mutagenic and others that are less so, and when the former get turned on we get a burst of mutations.

"Since we need to be able to weed out bad mutations, this imposes an upper bound of ~10^8 on the number of functional base pairs."

Definitely no more than 10^8 sites that would mutate into dominant lethals. For lesser deleterious mutations it gets murkier.

But there's nothing special mathematically about the constant 10^-8 -- that (unless I'm mistaken) is just an unwelcome intruder from physics and chemistry. So by using an error-correcting code, could we make the "effective mutation rate" nonzero, but as far below 10^-8 as we wanted?

Yes, and it happens some.

Indeed we could! Here's my redesigned, biology-beating DNA that achieves this. Suppose we want to simulate a mutation rate ε<<10^-8, allowing us to maintain ~1/ε functional base pairs in a steady state. Then we simply stick those 1/ε base pairs (in unencoded form) into our DNA strand, and also stick in "parity-check pairs" from a good error-correcting code. These parity-check pairs let us correct as many mutations as we want, with only a tiny probability of failure.

It's been years since I've looked at this. I may have some of it wrong and it might have changed while I wasn't looking. But one way we used to handle that was to keep track of which strand of DNA is the old known strand and which is the new one. Then if there's a mismatch, you repair the new one instead of the old one.

If you have two copies of the DNA sequence and one of them is being replicated while the other waits, and there's an error, you can copy DNA from the reserve copy and splice it into one or both of the new ones.

Since each DNA repair system might possibly do misrepair under some circumstance, and since they are potentially disruptive, it makes some sense that they would only be activated when needed.

Comment by J_Thomas on Natural Selection's Speed Limit and Complexity Bound · 2007-11-05T17:37:32.000Z · LW · GW

Eliezer, could you provide a link to this result? Something looks wrong about it.

Fisher's fundamental theorem of natural selection says the rate of natural selection is directly proportional to the variance in additive fitness in the population. At first sight that looks incompatible with your result.

You mention a site with selection at 0.01%. This would take a very long time for selection to act, and it would require that there not be stronger selection on any nearby linked site. It seems implausible that this site would have been selected before, with the result that it should be a 50:50 chance whether each change is a small favorable or unfavorable one. Tiny selective effects are neutral for all practical purposes. But tiny unfavorable changes have only a tiny chance to spread in the same way that you have little chance to win big at the casino when you make a very long series of small bets with the odds a little bit against you. Tiny favorable changes have only a very small chance to spread because they're usually lost by accident before they get a large enough stake.

Your numbers are clearly correct when all mutations are dominant lethal ones. When the mutation rate is high enough that half the offspring get a dominant lethal mutation, and there are only twice as many offspring as parents, then the population can barely survive those mutations and any higher mutation rate would drive it extinct.

I'm not sure that reasoning applies to mutations that affect relative reproduction rather than absolute, though. When a mutation lets its bearer survive better than other individuals when competing with them, but they survive just fine when it isn't around, that could be a different story.

Clearly there are limits to the rate of natural selection. It's proportional to the variance in fitness, so anything that limits the variation in fitness limits the rate of evolution. Mutation and recombination create variation in fitness, and there's some limit on the mutation rate because of mutations that reduce the absolute level of functioning of the organism. But the reasoning expressed in the post doesn't look convincing to me.

Comment by J_Thomas on Natural Selection's Speed Limit and Complexity Bound · 2007-11-04T19:26:10.000Z · LW · GW

However, mutation rates vary and can be selected. They aren't simply a constraint.

Also, it's been a long time since I've thought about this and I may be wrong, but aren't you talking about 1 bit per linkage group and not one bit per genome? (And the size of linkage groups also varies and can be selected.)

Some viruse genomes face severe constraints on size -- they have a container they must fit into -- say an icosahedral shape -- and it would be a big step to increase that size. And some of those make proteins off both strands of DNA and sometimes in more than one reading frame. 3 proteins from the same DNA sequence. Presumably each protein is less efficient than it might be if the DNA evolved to make it alone, but they do an adequate job of reproducing the virus.

Probably size constraints can usually be fudged better than that.

You can make mathematical theories about evolution, but they're highly sensitive to their beginning assumptions. It's too soon to say how far evolution has gone to produce genetic mechanisms that let evolution proceed more efficiently.

Comment by J_Thomas on A Case Study of Motivated Continuation · 2007-11-01T08:03:52.000Z · LW · GW

Douglas, I see nothing about strain w that's surprising. Would you like to suggest a blog and a thread to discuss this?

Comment by J_Thomas on A Case Study of Motivated Continuation · 2007-11-01T07:04:03.000Z · LW · GW

Douglas, I see nothing about strain w that's surprising. Would you like to suggest a blog and a thread to discuss this?

Comment by J_Thomas on A Case Study of Motivated Continuation · 2007-11-01T05:23:16.000Z · LW · GW

Michael Vassar, yes! Thank you for putting it so clearly.

Comment by J_Thomas on A Case Study of Motivated Continuation · 2007-11-01T05:21:43.000Z · LW · GW

Douglas, my own bias is to think that evolution has given us 3 billion+ years of selection for evolving faster. And multicellular organisms (a small minority of the total but interesting to us) have found ways to make genetic "modules" that result in phenotypes which fit together in a modular way. Chordates build a variety of structures from keratin. Arthropods build a big variety of limbs. Etc. The body plans that are most flexible speciate into the largest variety of niches -- nematodes, arthropods, mollusks, and chordates, and you have the big majority of animal species in just those 4 phyla.

We don't make just random changes, we have "hotspots" that change a lot while others are mostly held fixed. A big variety of mechanisms evolved that encourage faster evolution, because those mechanisms are themselves selected.

Apologies for the off-topic note.

Comment by J_Thomas on A Case Study of Motivated Continuation · 2007-10-31T18:36:31.000Z · LW · GW

When people can't explain themselves they often make up answers.

"What the hell? A blue tentacle?"

"I must have gotten it from a toilet seat."