Les gènes de collaboration

Par Kristopher Hite.

Traduit par Yann Aubertin

Le trait que j'admire le plus chez une personne pensante est la capacité à se divertir avec une idée sans nécessairement tout croire de cette idee. Avec cela à l'esprit, je m'empressai d'écouter une conference donnee par E.O. Wilson sur « les épaules des géants » à la « Fête de la Science du Monde » à New York la semaine dernière.

J'ai récemment écrit à propos de E.O Wilson et sur sa reconsideration controversée de l'altruisme. Longue histoire courte, Wilson a créé une contreverse en abandonnant sa conviction de longue date et prone l'idee selon laquelle la coopération et le comportement altruiste chez les micro-organismes peuvent être simplement expliqué comme un égoïsme dissimule. Quand un organisme semble se comporter de maniere altruiste en se sacrifiant lui-même ou en se metant en danger, c'est en fait juste un gene individuel manoeuvrant pour la survie, qui ferait des copies identiques de lui-même vivant parmis un groupe de meme famille. Cette théorie est connue sous le nom de « Fitness Inclusive ».

Au lieu de continuer de develloper sa theorie du  « fitness inclusive » E.O. Wilson semble maintenant embrasser la notion controversée de «sélection de groupe." C'est l'idée que les gènes altruistes persistent en bénéficiant de l'action d'ensemble du groupe. Le trait altruiste persiste en aidant les groupes eux-mêmes  

a se multiplier; croître dans les réseaux de plus en plus grand avec plus en plus de biomasse. Dans cette théorie de la sélection du groupe tout cela se produit malgré le fait que le caractère altruiste est nuisible à l'individu. Les gènes altruistes s'unissent et coopèrent en concurrence avec des groupes de gènes qui agissent égoïstement.

Pour moi, il me semble que les deux modèles pourraient s'appliquer à des gènes différents.

Après la conference, j'ai eu l'occasion rare de questionner directement E.O Wilson au sujet de son récent changement de position et lui ai demandé :

    "Si le gène est l'unité fondamentale de la sélection, la chose physique qui fait le tamis de la sélection naturelle-, alors pourquoi avons-nous besoin d'un modèle de« sélection de groupe »? Et si un gène n'est pas l'unité de base de la sélection, alors qu'est-ce est? "

La question a frappé un point sensible. Wilson a répondu qu'il l'avait anticipe, il a rapidement reconnu que son récent « déménagement » loin de la théorie de l'inclusive fitness avait ulcéré de nombreuses personnes, y compris le célèbre biologiste évolutionniste Richard Dawkins qui a popularisé l'idée du « gene-égoïste » de l'évolution et a été par la suite un critique virulent de la « sélection de groupe ». Mais Wilson a campé sur ses positions, en disant:

    "Oui, le gène est l'unité fondamentale de la sélection, mais le phénotype est la cible. C'est aussi simple que cela."


Wilson me lança un sourire, et pendant un moment j'étais fasciner, pris dans la lueur de charme légendaire de Wilson. J'ai brisé  l'enchantement quand j'ai vraiment commencé à mâcher sur sa réponse. J'étais encore très confus au sujet de la façon dont le concept de «phénotype comme cible" était censé justifier la theorie de « groupe de sélection » . Comme je l'accompagne en bas de l'ascenseur, je me suis senti un sentiment de culpabilité et n'ai pas appuye plus fort. J'ai alors imaginé un petit Richard Dawkins assis sur mes épaules, avec un froncement de sourcils, me réprimandant, "Kristopher, tu ne te souviens magnifiquement comment j'ai expliqué tout cela dans mon livre « The Selfish Gene »? Comment pourriez-vous douter de moi ? Hamilton avait raison, le gène est l'Anneau Unique pour les gouverner tous, tout le reste est un mythe! "

Sur l'autre épaule ( «épaule de géant," pourrait-on dire car je fais presaue deux metres), je me représentais une EO Wilson en miniature, toujours charmant dans son blazer en tweed , me rassurer, "Kristopher, tout va bien se passer aussi longtemps que nous travaillons ensemble dans ce grand plaisir par des pairs de notre groupe."

J'étais et  suis encore déchiré. Comme nous sortions de l'ascenseur, je rencontré par hasard le prix Nobel 1989 de Medecine, Harold Varmus, ancien chef de la « National Institute of Health », et j'ai eu l'occasion de lui demande comment il interpetrait ce que  EO Wilson voulait dire quand il annonce que le «phénotype est la cible de la sélection." Le Dr Varmus a peu précisé. Le phénotype a t-il expliqué, est le trajet du véhicule « gène » à l'intérieur de la manifestation physique des gènes.  Pression sélective de l'environnement, comme l'évolution des niveaux d'oxygène dans l'atmosphère, ou le changement des climats locaux ne sont pas capables d'agir directement sur n'importe quel gène isolé.

Après avoir dirigé le Dr Varmus et sa femme à la station de métro de la rue la plus proche, j'ai continué à tourner sa réponse dans ma tête. Si la sélection naturelle se passe au niveau de la manifestation physique des gènes, le phénotype, et qu'il n'y a aucun organisme dans la nature comportant un seul gène, alors tous les gènes doitvent être collaboratif dans un sens.

Et c'est là que j'en suis dans mon processus de pensée. Si vous avez des corrections ou des critiques, je leur souhaitent la bienvenue. Ils ne feront qu'ajouter à ma compréhension.

Posté par Ghost Tom Paine. Traduit par Yann Aubertin.

Collaborative Genes

By Kristopher Hite

The trait I admire most in a fellow thinker is the ability to entertain an idea without necessarily swallowing it whole. With that in mind, I eagerly listened to E.O. Wilson's On the Shoulders of Giants address at the World Science Festival in New York City last week.

I recently wrote about Wilson and his controversial rethink of altruism. Long story short, Wilson has created a ruckus by abandoning his long-held belief that cooperative and altruistic behavior among organisms can be simply explained as a veiled selfishness. When an organism appears to behave altruistically by sacrificing themselves or putting themselves in danger it is actually just the individual genes jockeying to survive by keeping identical copies of themselves alive in their relatives. This theory is known as inclusive fitness.

 In place of inclusive fitness E.O. Wilson now seems to embrace the controversial concept of “group selection.” This is the idea that genes for altruism persist by benefiting the entire group. The altruistic trait persists by helping groups themselves multiply; grow into larger and larger networks with more and more biomass. In group selection theory this all happens despite the fact that the altruistic trait is detrimental to the individual. Altruistic genes that band together and cooperate out compete groups of genes that act selfishly.

To me, both models seem like they could apply to different genes.

After the address, I had the rare opportunity to ask Wilson directly about his recent change of heart. I asked,

"If the gene is the basic unit of selection—the physical thing that makes it though the sieve of natural selection—then why do we need a 'group selection' model? And if a gene is not the basic unit of selection, then what is?" 

The question struck a chord. Wilson replied that he had been anticipating it, in fact, and quickly acknowledged that that his recent move away from the theory of inclusive fitness had rankled many people, including the famed evolutionary biologist Richard Dawkins who has popularized the selfish-gene view of evolution and has been a vocal critic of group selection. But Wilson stuck to his guns, saying,

"Yes, the gene is the basic unit of selection, but the phenotype is the target. It is as simple as that." 

Wilson flashed a smile, and for a moment I was starstruck, caught up in the glow of Wilson's legendary charm. The spell broke when I began to really chew on his answer. I was still extremely confused about how the concept of "phenotype as target" was supposed to justify group-selection theory. As I rode the elevator downstairs, I felt a pang of guilt for not pressing harder. I imagined a tiny Richard Dawkins sitting on my shoulder, eyebrows in a scowl, chiding me, "Kristopher, don't you remember how beautifully I explained all this to you in my book, The Selfish Gene?? How could you turn on me? Hamilton had it right, the gene is the one ring to rule them all everything else is myth!"

On the other shoulder (the "giant shoulder," one might say), I pictured a miniature E.O. Wilson, still charming in his diminutive tweed blazer, reassuring me, "Kristopher, everything is going to be alright as long as we work together in this big happy peer-reviewing group of ours."

I was, and still am, torn. As I stepped out of the elevator, I serendipitously met Nobel Laureate Harold Varmus, former head of the NIH, and I took the opportunity to ask him what he thought E.O. Wilson meant when he said "phenotype is the target of selection." Dr. Varmus clarified—somewhat. Phenotype, he explained, is the vehicle genes ride inside the physical manifestation of the genes. Selective environmental pressure, like changing atmospheric oxygen levels, or changing local climates are not capable of acting directly on any single isolated gene.

After I directed Dr. Varmus and his wife to the Christopher Street subway station, I continued to replay his answer in my head. If natural selection happens at the level of the physical manifestation of the genes – the phenotype, and there is no organism in existence with only one gene inside, then all genes must be collaborative in a sense.

And this is where I am in my thought process. If you have any corrections or criticisms I welcome them. They will only add to my understanding.

Good for Goodness' Sake?

I have decided to focus my "homework" leading up to the World Science Festival on E.O. Wilson and his recent change of mind regarding a long-held tenet of evolutionary biology - inclusive fitness. The theory of inclusive fitness provides a logical and mathematical framework to rationalize kin-selection. Kin-selection explains why behavioral traits such as self-sacrifice come to be in certain species. Although it appears an organism is sacrificing their life for the "greater-good" they are really just behaving that way so that their genes can be passed on through their relatives who they are trying to help survive. Wilson has abandoned the idea that altruistic behavior emerges out of the struggle for existence as previously explained by a simple equation championed by none other that HIMSELF at an earlier stage in his life. The equation is rB>C. In which r is a relatedness factor B is the fitness Benefit to the altruistic organism and C is the Cost of genetic fitness to the organism for carrying out the act of altruism. This equation was put forth and formalized by the British evolutionary biologist W.D. Hamilton in the 1960's.

So why has Wilson changed his mind about inclusive fitness? In a 2010 paper in the prestigious scientific journal Nature Wilson, along with colleagues Martin Nowak and Corina Tarnita claim there is not enough evidence in the real world of organisms who display altruistic behavior that follow the rule rB>C. They go further to say that the factors in the equation, B and C are too difficult to quantify.  Wilson admits the equation is simple, elegant, and alluring however he maintains that it is too simple and needs revision.

Wilson's flip-flop (btw, I am not using flip-flop in a negative way here as I think in science changing one's mind is a virtue not a vice) has caused an uproar in the scientific community drawing heavy criticism from some of the most vocal evolutionary biologists including Jerry Coyne and Richard Dawkins.  Wilson's critics have said he is using his authority to make assumptions without backing up his claims with real-world data (though Wilson does cite termite and ambrosia beetle societies). Wilson fires back at them with the same criticism, saying they have a lack of data on their side (though they do cite sawfly, wasp and bee societies). This makes for the juiciest kind of intellectual debate, one that sends scientists out in the field in search for more evidence.

Meanwhile, Wilson's apparent embrace of "group-selection" has opened the flood-gates for scholars from the humanities to jump on board the cooperation-train and use "group-selection" to explain social phenomenon like the persistence of religion in human society and the rapid growth of social networks. Among these are psychologist Jonathan Haidt and social commentator David Brooks. The worry here is that the scientific debate over evidence will be overlooked by the hungry mobs of humanitarians so eager to extract rationale for morals out of biology. 

I am excited to go into this debate and try as I might to filter out the wheat from the chaff when it comes to sound-science.  It gets particularly noisy when morals get involved. I have seen this before at the World Science Festival as I covered the last "Faith and Science" discussion panel in 2010. My big worry is that the conversation will devolve into a silly argument about the participants underlying motives as the festival is in large part funded by a controversial organization called the John Templeton Foundation.  Compounding this fear of mine is that Matin Nowak (the Austrian born, Harvard mathematician, and co-author of E.O.Wilson's) has received many millions of dollars form the Templeton foundation for his research.  Indeed, many of the intellectuals in the Wilson camp are notorious in the scientific community for receiving money from Templeton (Jonathan Haidt winning the Templeton prize in 2001.)  My hope is that the conversation can stick to the science and not get railroaded by money and politics. 

This post has been entered into the National Evolutionary Synthesis Center's travel award contest. Winner's will receive money to help pay for the travel expenses for attending the Science Online conference to be held at the end of January 2013 in Raleigh, North Carolina. Apply for the travel award here!

Multi-level selection

I've been watching with great anticipation as one of the oldest battles in evolutionary biology is being born anew this year thanks to E.O. Wilson and his mathematical comrades Martin Nowak and Corina Tarnita. The trio lead by the old sage - Wilson - has in essence capsized the boat when it comes to the debate between group-selection and kin-selection.

As a bright-eyed college freshman I was made to read the selfish gene by Richard Dawkins. In this book Dawkins lays out a strong case for kin-selection and the rugged individual as embodied by "the gene." This world-view provides the logical starting point when building an argument for "kin-selection." E.O. Wilson was in the kin-selection camp for decades, indeed he was there close to the birth of the concept. But now looking back at his long career he has made an epic flip-flop (which consequentially I think is a high virtue in science despite being maligned by politicos the country over).

Wilson's flip-flop is away from kin-selection and towards group selection. I learned more about his opinions regarding this philosophy in this rough-cut interview with Carl Zimmer. A core concept Wilson acknowledges is not well developed is multi-level selection. Mult-level selection is a more nuanced approach to understanding group-selection. Wilson suggests multi-level selection ought to be fleshed out in order to replace what he considers the erroneous inclusive-fitness theory.

I had not grasped what "multi-level" selection meant until I got to 9:00 in the following TED talk by Jonathan Hiadt. Here he explains in basic terms what multi-level selection theory looks like using a crew-team to illustrate his point. I immediately thought of the novel All Quiet on the Western Front by Erich Remarque. One of the continuous themes is the hatred the main character and all of his fellow soldiers feel toward their commanding officer. One of the most gruesome scenes in the book is an ambush of the officer his own men orchestrate. They beat him to within an inch of his life to let him know he does not control them. This internal conflict is more nuanced than the conflict with the enemy and also illustrates one layer in multi-level evolution theory. Please watch the video and let me know what you think.