J_Thomas

Karma: 150

J_Thomas Nov 17, 2007, 12:24 AM
0 points
on: Evolving to Extinction
“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?

J_Thomas Nov 17, 2007, 12:11 AM
2 points
on: Evolving to Extinction
‘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.

J_Thomas Nov 15, 2007, 1:01 PM
0 points
on: Fake Selfishness
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.

J_Thomas Nov 15, 2007, 11:20 AM
6 points
on: Terminal Values and Instrumental Values
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.

J_Thomas Nov 15, 2007, 2:52 AM
0 points
on: Thou Art Godshatter
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.

J_Thomas Nov 14, 2007, 8:56 PM
0 points
on: Thou Art Godshatter
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.

J_Thomas Nov 14, 2007, 12:53 PM
0 points
on: Thou Art Godshatter
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.

J_Thomas Nov 14, 2007, 12:15 PM
0 points
on: An Alien God
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.

J_Thomas Nov 14, 2007, 4:05 AM
0 points
on: Protein Reinforcement and DNA Consequentialism
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.

J_Thomas Nov 14, 2007, 3:56 AM
−1 points
on: Thou Art Godshatter
“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.

J_Thomas 14 Nov 2007 0:42 UTC
−9 points
on: Thou Art Godshatter
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.

J_Thomas 13 Nov 2007 12:06 UTC
0 points
on: Protein Reinforcement and DNA Consequentialism
“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.

J_Thomas 13 Nov 2007 2:58 UTC
13 points
on: Burch’s Law
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....

J_Thomas 13 Nov 2007 2:41 UTC
4 points
on: Protein Reinforcement and DNA Consequentialism
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.

J_Thomas 11 Nov 2007 17:23 UTC
31 points
0
on: Adaptation-Executers, not Fitness-Maximizers
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.

J_Thomas 11 Nov 2007 0:48 UTC
2 points
on: Beware of Stephen J. Gould
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?

J_Thomas 10 Nov 2007 21:43 UTC
4 points
on: Beware of Stephen J. Gould
“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.

J_Thomas 10 Nov 2007 20:51 UTC
0 points
on: The Tragedy of Group Selectionism
‘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.

J_Thomas 10 Nov 2007 19:54 UTC
3 points
on: Beware of Stephen J. Gould
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.

J_Thomas 10 Nov 2007 13:05 UTC
0 points
on: Beware of Stephen J. Gould
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.