LIFE

ON "ITERATED PRISONER'S DILEMMA CONTAINS STRATEGIES THAT DOMINATE ANY EVOLUTIONARY OPPONENT"

[6.18.12]

"Robert Axelrod's 1980 tournaments of iterated prisoner's dilemma strategies have been condensed into the slogan, Don't be too clever, don't be unfair. Press and Dyson have shown that cleverness and unfairness triumph after all." — William Poundstone, from his Commentary

Introduction

In January I had the occasion to spend sometime in Munich with Freeman Dyson who informed me about a paper on "The Prisoner's Dilemma" he had co-authored with William H. Press, and he then briefly sketched out some of its ramifications. He indicated that they had come up with something new, a way to win the game. It's simple, he said. The winning strategy: go to lunch. And, he added, the only way to trump this strategy is to come up with a new theory of mind. I tried to go deeper but, he said, "I don't really understand game theory, I just did the math. This is really Bill Press's work."

The highly technical paper, "Iterated Prisoner’s Dilemma contains strategies that dominate any evolutionary opponent" by William H. Press and Freeman J. Dyson has now been published in PNAS (May 22, 2012), which was followed by a PNAS Commentary by Alexander Stewart and Joshua Plotkin of the Department of Biology, University of Pennsylvania, entitled "Extortion and cooperation in the Prisoner’s Dilemma" (June 18, 2012). Here's the Abstract of the paper:

"The two-player Iterated Prisoner’s Dilemma game is a model for both sentient and evolutionary behaviors, especially including the emergence of cooperation. It is generally assumed that there exists no simple ultimatum strategy whereby one player can enforce a unilateral claim to an unfair share of rewards. Here, we show that such strategies unexpectedly do exist. In particular, a player X who is witting of these strategies can (i) deterministically set her opponent Y’s score, independently of his strategy or response, or (ii) enforce an extortionate linear relation between her and his scores. Against such a player, an evolutionary player’s best response is to accede to the extortion. Only a player with a theory of mind about his opponent can do better, in which case Iterated Prisoner’s Dilemma is an Ultimatum Game."

Edge asked William Poundstone, author of  the book The Prisoner's Dilemma, to explain the paper in non-technical terms. In his Commentary below, he writes:

"Robert Axelrod's 1980 tournaments of iterated prisoner's dilemma strategies have been condensed into the slogan, Don't be too clever, don't be unfair. Press and Dyson have shown that cleverness and unfairness triumph after all."

Also below are responses by William Press to Poundstone and by Freeman Dyson to Stewart and Plotkin.

To kick off a Reality Club conversation, mathematician Karl Sigmund at University of Vienna, and biological mathematician Martin Nowak of Harvard, two pioneers of evolutionary game theory, comment below.

 JB

THE REALITY CLUB: Karl Sigmund & Martin Nowak


TALES FROM THE WORLD BEFORE YESTERDAY

[12.31.12]

 

INTRODUCTION

Over the years I've had the privilege to work with some of the more interesting thinkers of our time, individuals who, through their research in biology, physics, psychology, computer science, provide us with the evidence-based results that are the basis of the most reliable method of our knowledge about who and what we are. In this regard, nothing beats sitting down with Jared Diamond after one of his many (41 to date) trips to New Guinea to listen to this master story-teller hold forth on the windows to our past, whether the topic is rare birds, "primitive peoples", birth practices, the lives of the old, war, or the characteristics of all human societies until the rise of state societies with laws and government, beginning around 5,500 years ago.

A few months ago I visited him at his home in Bel Air, California, just a few doors up the road from the Bel Air Hotel. We sat for an hour while he recounted some of his experiences in New Guinea. Fortunately, I had my video camera with me. What follows are three videotaped stories, which I have taken the liberty of presenting with the following titles:

• "If You Camp Under Dead Trees, And Each Dead Tree Has A One In 1,000 Chance Of Falling On You And Killing You"

• "One Of The Stupider, More Dangerous Things That I Did In My Life"

• "How I Discovered The Long-Lost Bowerbird, Initially Without Realizing It"

— JB

JARED DIAMOND is Professor of Geography at the University of California, Los Angeles. His latest book, published today, is The World Until Yesterday: What Can We Learn from Traditional Societies? His other books include Collapse: How Societies Choose to Fail or Succeed, and the Pulitzer Prize-winning author of the widely acclaimed Guns, Germs, and Steel: the Fates of Human Societies, which is the winner of Britain's 1998 Rhone-Poulenc Science Book Prize. 

Jared Diamond's Edge Bio Page

The significance of the guy holding out his arm, dipping at the wrist, is that that's a gesture that magicians use to imitate the cassowary. The cassowary is New Guinea's biggest bird. It's flightless. It's like a small ostrich. Weighs up to 100 pounds. And it has razor-sharp legs that can disembowel a man. The sign of the cassowary, if you hold out your arm like this, that's the cassowary rolling its head and dipping its head when it's ready to charge. So magicians will imitate a cassowary in order to show their power. Because the cassowary's big and powerful. Magicians identify with the cassowary. They intimidate people.


 

TALES FROM THE WORLD BEFORE YESTERDAY

Topic: 

  • LIFE
http://vimeo.com/81862835

The significance of the guy holding out his arm, dipping at the wrist, is that that's a gesture that magicians use to imitate the cassowary. The cassowary is New Guinea's biggest bird. It's flightless. It's like a small ostrich. Weighs up to 100 pounds. And it has razor-sharp legs that can disembowel a man. The sign of the cassowary, if you hold out your arm like this, that's the cassowary rolling its head and dipping its head when it's ready to charge. So magicians will imitate a cassowary in order to show their power. Because the cassowary's big and powerful.

TESTOSTERONE ON MY MIND AND IN MY BRAIN

[4.30.12]

This is a hormone that has fascinated me. It's a small molecule that seems to be doing remarkable things. The variation we see in this hormone comes from a number of different sources. One of those sources is genes; many different genes can influence how much testosterone each of us produces, and I just wanted to share with you my fascination with this hormone, because it's helping us take the science of sex differences one step further, to try to understand not whether there are sex differences, but what are the roots of those sex differences? Where are they springing from? And along the way we’re also hoping that this is going to teach us something about those neuro-developmental conditions like autism, like delayed language development, which seem to disproportionately affect boys more than girls, and potentially help us understand the causes of those conditions.

Introduction by John Brockman

"I thoroughly enjoyed the evening last week," emailed Brian Eno. "A lot of interesting people got connected together and everyone told me they enjoyed themselves."

He was referring the first-ever London Edge Reality Club meeting, featuring a presentation by Cambridge research psychologist Simon-Baron Cohen which Eno hosted at his studio in Notting Hill before an assembled group that included artists, curators, museum directors, writers, playwrights, scientists in fields such as biology, math, psychology, zoology, the editors and correspondents of Nature, The Economist, Wired, The Guardian. ... [CONTINUED]

SIMON BARON-COHEN, Psychologist,  is Professor of Developmental Psychopathology and Director of the Autism Research Centre at Cambridge University, a Fellow of Trinity College, Cambridge; Author, The Science of Evil; The Essential Difference.

Simon Baron-Cohen's Edge Bio Page

 

TESTOSTERONE ON MY MIND AND IN MY BRAIN

Topic: 

  • LIFE
https://vimeo.com/82232360

"This is a hormone that has fascinated me. It's a small molecule that seems to be doing remarkable things. The variation we see in this hormone comes from a number of different sources. One of those sources is genes; many different genes can influence how much testosterone each of us produces, and I just wanted to share with you my fascination with this hormone, because it's helping us take the science of sex differences one step further, to try to understand not whether there are sex differences, but what are the roots of those sex differences? Where are they springing from?

Lynn Margulis 1938-2011 "Gaia Is A Tough Bitch"

[11.23.11]

Introduction
By John Brockman

Biologist Lynn Margulis died on November 22nd. She stood out from her colleagues in that she would have extended evolutionary studies nearly four billion years back in time. Her major work was  in cell evolution, in which the great event was the appearance of the eukaryotic, or nucleated, cell — the cell upon which all larger life-forms are based. Nearly forty-five years ago, she argued for its symbiotic origin: that it arose by associations of different kinds of bacteria. Her ideas were generally either ignored or ridiculed when she first proposed them; symbiosis in cell evolution is now considered one of the great scientific breakthroughs.

Margulis was also a champion of the Gaia hypothesis, an idea developed in the 1970s by the free lance British atmospheric chemist James E. Lovelock. The Gaia hypothesis states that the atmosphere and surface sediments of the planet Earth form a self- regulating physiological system — Earth's surface is alive. The strong version of the hypothesis, which has been widely criticized by the biological establishment, holds that the earth itself is a self-regulating organism; Margulis subscribed to a weaker version, seeing the planet as an integrated self- regulating ecosystem. She was criticized for succumbing to what George Williams called the "God-is good" syndrome, as evidenced by her adoption of metaphors of symbiosis in nature. She was, in turn, an outspoken critic of mainstream evolutionary biologists for what she saw as a failure to adequately consider the importance of chemistry and microbiology in evolution.

I first met her in the late 80's and in 1994 interviewed her for my book The Third Culture: Beyond the Scientific Revolution (1995). Below, in remembrance, please see her chapter, "Gaia is a Tough Bitch". One of the compelling features of The Third Culture was that I invited each of the participants to comment about the others. In this regard, the end of the following chapter has comments on Margulis and her work by Daniel C. Dennett, the late George C. Williams, W. Daniel Hillis, Lee Smolin, Marvin Minsky, Richard Dawkins, and the late Francisco Varela. Interesting stuff. 

As I wrote in the introduction to the first part of the book (Part I: The Evolutionary Idea): "The principal debates are concerned with the mechanism of speciation; whether natural selection operates at the level of the gene, the organism, or the species, or all three; and also with the relative importance of other factors, such as natural catastrophes." These very public debates were concerned with ideas represented by George C. Williams and Richard Dawkins on one side and Stephen Jay Gould and Niles Eldredge on the other side. Not for Lynn Margulis. All the above scientists were wrong because evolutionary studies needed to begin four billion years back in time. And she was not shy about expressing her opinions. Her in-your-face, take-no-prisoners stance was pugnacious and tenacious. She was impossible. She was wonderful.

Margulis conversation thread

[11.23.11]

Introduction
By John Brockman

Biologist Lynn Margulis died on November 22nd. She stood out from her colleagues in that she would have extended evolutionary studies nearly four billion years back in time. Her major work was  in cell evolution, in which the great event was the appearance of the eukaryotic, or nucleated, cell — the cell upon which all larger life-forms are based. Nearly forty-five years ago, she argued for its symbiotic origin: that it arose by associations of different kinds of bacteria. Her ideas were generally either ignored or ridiculed when she first proposed them; symbiosis in cell evolution is now considered one of the great scientific breakthroughs.

Margulis was also a champion of the Gaia hypothesis, an idea developed in the 1970s by the free lance British atmospheric chemist James E. Lovelock. The Gaia hypothesis states that the atmosphere and surface sediments of the planet Earth form a self- regulating physiological system — Earth's surface is alive. The strong version of the hypothesis, which has been widely criticized by the biological establishment, holds that the earth itself is a self-regulating organism; Margulis subscribed to a weaker version, seeing the planet as an integrated self- regulating ecosystem. She was criticized for succumbing to what George Williams called the "God-is good" syndrome, as evidenced by her adoption of metaphors of symbiosis in nature. She was, in turn, an outspoken critic of mainstream evolutionary biologists for what she saw as a failure to adequately consider the importance of chemistry and microbiology in evolution.

I first met her in 1995 when I interviewed her for my book The Third Culture: Beyond the Scientific Revolution (1995). Below, in remembrance, please see her chapter, "Gaia is a Tough Bitch". One of the compelling features of The Third Culture was that I invited each of the participants to comment about the others. In this regard, the end of the following chapter has comments on Margulis and her work by Daniel C. Dennett, the late George C. Williams, W. Daniel Hillis, Lee Smolin, Marvin Minsky, Richard Dawkins, and the late Francisco Varela. Interesting stuff. 

As I wrote in the introduction to the first part of the book (Part I: The Evolutionary Idea): "The principal debates are concerned with the mechanism of speciation; whether natural selection operates at the level of the gene, the organism, or the species, or all three; and also with the relative importance of other factors, such as natural catastrophes." These very public debates were concerned with ideas represented by George C. Williams and Richard Dawkins on one side and Stephen Jay Gould and Niles Eldredge on the other side. Not for Lynn Margulis. All the above scientists were wrong because evolutionary studies needed to begin four billion years back in time. And she was not shy about expressing her opinions. Her in-your-face, take-no-prisoners stance was pugnacious and tenacious. She was impossible. She was wonderful.  

THE EDGE CONVERSATION:

Ed Regis
Science writer; Author, What Is Life?

The best epitaph for Lynn Margulis probably consists of her own words, from a Discover magazine Q&A with her, published earlier this year:   

Q: Do you ever get tired of being called controversial?   
A: I don’t consider my ideas controversial. I consider them right.   

George Dyson
Science Historian, Author, Darwin Among the Machines; Turing's Cathedral (forthcoming)

Lynn Margulis did much of the hard work (preceded by some heretic Russians, and the even more heretic Samuel Butler) of opening the doorway I was able to walk through with "Darwin Among the Machines". She titled her review in the "Times Higher Education Supplement" (14 August 1998) "Perfection in Grenade Throwing," a reference not only to Samuel Butler's long-running critique of Charles Darwinism, but to William Calvin's theory of mental evolution through sequence-buffering for stone-throwing, and certain lingering repercussions of the trench warfare that dominated World War I. Lynn Margulis was herself among the elite of scientific grenade throwers, and long-entrenched positions shifted when she scored a hit.

Nicholas Pritzker 
Chairman of the Board and CEO of the Hyatt Development Corporation

In my teen-age years, my science side danced with my fascination with metaphysical concepts.   was amazed by the discovery of the CMB, but equally so in trying to find connection between Beckett's novels, Magritte's surrealism, symbolic logic and the Rinzai Zen koan: the basis of my undergraduate thesis in 1969. At the time, I thought of Gaia as a mystical concept (the "god is good" idea).  Later, as science decisively won the race for my attention, I was startled to learn that at least some of the Gaia thinkers, especially Margulis, were working with scientifically valid theories but within a novel conceptual context. This approach lends itself to misinterpretation, but seems to me worth the risk!  

Jerry Coyne
Professor, Department of Ecology and Evolution, University of Chicago; author, Why Evolution is True

Lynn Margulis did indeed have a clever—and correct—idea that revolutionized our view of how life evolved, but later became a victim of the Big Idea Syndrome, thinking that because she was right about organelles, she was right about everything else. That led her to make repeated and completely unfounded attacks on evolutionary biology in the last decade, embarrassing herself with her pronouncements. Her legacy is a good one, but not unmixed.  

Rereading her chapter "Gaia is a Tough Bitch" only reinforces my opinion about her  misguided criticisms of neo-Darwinian evolution and her unwarranted antipathy toward population genetics. Not only did she fail to comprehend how population genetics has advanced our understanding of nature—the effects of inbreeding and of genetic drift are two such advances—but her views on speciation, a field in which I've worked for three decades, are simply wrong.  

Margulis's idea that new species originate from symbiosis has no empirical support. When we try to understand the genetic underpinnings of new species, we find that, with the exception of polyploidy in plants, it always maps to changes in the DNA.  That is, the splitting of lineages, like evolution within a lineage itself, is almost always the result of gradual, gene-by-gene change. We have no evidence that symbiosis has been responsible for even a single case of speciation.  

All of us should honor Margulis's real contributions to biology: her recognition and working out of earlier suggestions that some cellular organelles were acquired by symbiosis, and that the ancestors of these organelles were bacteria. This was a tremendous advance, achieved in the teeth of substantial doubt. Sadly, Margulis's success in the face of such criticism seems to have made her stubborn and dogmatic about her other biological views.  And, even sadder, those theories were often wrong.  She strongly denied, for example, that AIDS was caused by the HIV virus, or that the HIV virus even existed.  AIDS, she maintained, was simply syphilis, with the spirochete rendered undetectable because it formed a symbiosis with human cells. How does one balance her positive contributions against such a deadly form of denialism?

We should always honor those scientists who have advanced our understanding of nature in ways as profound as Margulis. But let us also remember that being right about one big matter does not render us immune to error in other matters, and that scientific fame does not give us a free pass for all of our ideas.



LYNN MARGULIS was Distinguished University Professor in the Department of Geology at the University of Massachusetts, Amherst. She was the author of Symbiotic PlanetThe Origin of Eukaryotic CellsEarly Life, and Symbiosis in Cell Evolution. She was also the coauthor, with Karlene V. Schwartz, of Five Kingdoms: An Illustrated Guide to the Phyla of Life on Earth and with Dorion Sagan of Acquiring GenomesMicrocosmosOrigins Of Sex, and Mystery Dance.


Lynn Margulis 1938-2011

"Gaia Is A Tough Bitch"

[From The Third Culture: Beyond the Scientific Revolution (1995). Paperback: Amazon | B&NEdge Online Edition

Richard Dawkins: I greatly admire Lynn Margulis's sheer courage and stamina in sticking by the endosymbiosis theory, and carrying it through from being an unorthodoxy to an orthodoxy. I'm referring to the theory that the eukaryotic cell is a symbiotic union of primitive prokaryotic cells. This is one of the great achievements of twentieth-century evolutionary biology, and I greatly admire her for it.

[LYNN MARGULIS]: At any fine museum of natural history — say, in New York, Cleveland, or Paris — the visitor will find a hall of ancient life, a display of evolution that begins with the trilobite fossils and passes by giant nautiloids, dinosaurs, cave bears, and other extinct animals fascinating to children. Evolutionists have been preoccupied with the history of animal life in the last five hundred million years. But we now know that life itself evolved much earlier than that. The fossil record begins nearly four thousand million years ago! Until the 1960s, scientists ignored fossil evidence for the evolution of life, because it was uninterpretable.

I work in evolutionary biology, but with cells and microorganisms. Richard Dawkins, John Maynard Smith, George Williams, Richard Lewontin, Niles Eldredge, and Stephen Jay Gould all come out of the zoological tradition, which suggests to me that, in the words of our colleague Simon Robson, they deal with a data set some three billion years out of date. Eldredge and Gould and their many colleagues tend to codify an incredible ignorance of where the real action is in evolution, as they limit the domain of interest to animals — including, of course, people. All very interesting, but animals are very tardy on the evolutionary scene, and they give us little real insight into the major sources of evolution's creativity. It's as if you wrote a four-volume tome supposedly on world history but beginning in the year 1800 at Fort Dearborn and the founding of Chicago. You might be entirely correct about the nineteenth-century transformation of Fort Dearborn into a thriving lakeside metropolis, but it would hardly be world history.

Rethinking "Out of Africa"

Topic: 

  • LIFE
http://vimeo.com/79899367

"I'm thinking a lot about species concepts as applied to humans, about the "Out of Africa" model, and also looking back into Africa itself. I think the idea that modern humans originated in Africa is still a sound concept. Behaviorally and physically, we began our story there, but I've come around to thinking that it wasn't a simple origin. Twenty years ago, I would have argued that our species evolved in one place, maybe in East Africa or South Africa. There was a period of time in just one place where a small population of humans became modern, physically and behaviourally.

RETHINKING "OUT OF AFRICA"

[11.12.11]

I'm thinking a lot about species concepts as applied to humans, about the "Out of Africa" model, and also looking back into Africa itself. I think the idea that modern humans originated in Africa is still a sound concept. Behaviorally and physically, we began our story there, but I've come around to thinking that it wasn't a simple origin. Twenty years ago, I would have argued that our species evolved in one place, maybe in East Africa or South Africa. There was a period of time in just one place where a small population of humans became modern, physically and behaviourally. Isolated and perhaps stressed by climate change, this drove a rapid and punctuational origin for our species. Now I don’t think it was that simple, either within or outside of Africa. 

CHRISTOPHER STRINGER is one of the world's foremost paleoanthropologists. He is a founder and most powerful advocate of the leading theory concerning our evolution: Recent African Origin or "Out of Africa". He has worked at The Natural History Museum, London since 1973,  is a Fellow of the Royal Society, and currently leads the large and successful Ancient Human Occupation of Britain project (AHOB),  His most recent book is The Origin of Our Species (titled Lone Survivors in the US). 

Christopher Stringer's Edge Bio Page


Rethinking "Out of Africa" from Edge Foundation on Vimeo.


Rethinking "Out of Africa"

[CHRISTOPHER STRINGER:] At the moment, I'm looking again at the whole question of a recent African origin for modern humans—the leading idea over the last 20 years. This argues  that we had a recent African origin, that we came out of Africa, and that we replaced all of the other human forms that were outside of Africa. But we're having to re-evaluate that now because genetic data suggest that the modern humans who came out of Africa about 60,000 years ago probably interbred with Neanderthals, first of all, and then some of them later on interbred with another group of people called the Denisovans, over in south eastern Asia.

If this is so, then we are not purely of recent African origin. We're mostly of recent African origin, but there was contact with these other so-called species. We're having to re-evaluate the Out-of-Africa theory, and we're having to re-evaluate the species concepts we apply, because in one view of thinking, species should be self-contained units. They don't interbreed with other species. However, for me, the whole idea of Neanderthals as a different species is really a recognition of their separate evolutionary history—the fact that we can show that they evolved through time in a particular direction, distinct from modern humans, and they separated maybe 400,000 years ago from our lineage. And morphologically we can distinguish a relatively complete Neanderthal fossil from any recent human.

 

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