Egoísmo, Altruismo, Evolución y Memes: The Selfish Gene

De los varios libros de historia de las ciencias que pasaron por mis manos, siempre la parte más aburrida me resultó la referida a las ciencias naturales, tal es así que nunca consideré las potenciales ventajas de leer a Darwin. Me parecía que esas dos frases, “selección natural” y “supervivencia del más apto” eran frases que resumían adecuadamente todo lo que se podía plantear sobre el tema evolutivo.

Hasta qué punto estos conceptos se pueden elaborar para explicar cuestiones mucho más complejas como el comportamiento colaborativo entre especímenes, la rivalidad entre sexos, o las estructuras jerárquicas dentro de una especie eran cosas que me resultaban completamente ajenas.

Los temas planteados por Dawkins en The Selfish Gene, a pesar de haber sido escrito en 1976, están tan vigentes como los planteados por Einstein en sus teorías de la relatividad (especial y general). Una buena lectura para los estudiantes de ciencias sociales, presenta fundamentos científicos que ayudan a explicar comportamientos y fenómenos culturales básicos desde una perspectiva diferente a la que usualmente se adopta desde la política, la sociología, la economía o la comunicación.

Ahora al contenido: hay tres temas fundamentales en el libro de Dawkins, y cada uno podría ser un libro independiente.

Primero y fundamental, tesis central del libro, la idea de que la evolución opera a nivel del gen en lugar del individuo o del grupo. El gen es la unidad evolutiva fundamental, y desde este punto de vista Dawkins explica varios fenómenos de comportamiento grupales difíciles de explicar desde la perspectiva del individuo.

One way of sorting this whole matter out is to use the terms ‘replicator’ and ‘vehicle’. The fundamental units of natural selection, the basic things that survive or fail to survive, that form lineages of identical copies with occasional random mutations, are called replicators. DNA molecules are replicators. They generally, for reasons that we shall come to, gang together into large communal survival machines or ‘vehicles’. The vehicles that we know best are individual bodies like our own. A body, then, is not a replicator; it is a vehicle. I must emphasize this, since the point has been misunderstood. Vehicles don't replicate themselves; they work to propagate their replicators. Replicators don't behave, don't perceive the world, don't catch prey or run away from predators; they make vehicles that do all those things. For many purposes it is convenient for biologists to focus their attention at the level of the vehicle. For other purposes it is convenient for them to focus their attention at the level of the replicator. Gene and individual organism are not rivals for the same starring role in the Darwinian drama. They are cast in different, complementary and in many respects equally important roles, the role of replicator and the role of vehicle.

Desde ésta perspectiva, son los genes los que compiten entre ellos, y los organismos son “máquinas de supervivencia” que acarrean estos genes de generación en generación.

Individuals are not stable things, they are fleeting.

Chromosomes too are shuffled into oblivion, like hands of cards soon after they are dealt. But the cards themselves survive the shuffling. The cards are the genes. The genes are not destroyed by crossing-over, they merely change partners and march on. Of course they march on. That is their business. They are the replicators and we are their survival machines. When we have served our purpose we are cast aside. But genes are denizens of geological time: genes are forever.

Y estos genes egoístas, suelen programar máquinas que también tienen un comportamiento egoísta. Una de las principales críticas que ha recibido desde su publicación es que indirectamente apoya el determinismo genético.

Lo que nos lleva al segundo gran tema tratado en el libro, el comportamiento grupal y las estrategias evolutivamente estables.

Me acuerdo de que hace años, en algún cumpleaños, tuve una discusión con alguien sobre la naturaleza del hombre. De fondo la discusión era sobre la validez, en términos Hobbsianos de la frase inmortalizada en Leviatan “Homo homini lupus”. En esa época no podía concebir la idea de que el estado de naturaleza del hombre fuera egoísta, porque de ahí desprendía una moralidad y una forma de entender la realidad del hombre que me resultaba muy desagradable.

El error es justamente pretender que existe una moralidad natural, cualquier moralidad es puramente cultural, y no tendría qué desprenderse de nuestro entendimiento de la naturaleza.

Dawkins explicita en su libro que las formas en que operó la evolución no implican que tengamos que basar nuestro comportamiento en esos principios:

I am not advocating a morality based on evolution. I am saying how things have evolved. I am not saying how we humans morally ought to behave. I stress this, because I know I am in danger of being misunderstood by those people, all too numerous, who cannot distinguish a statement of belief in what is the case from an advocacy of what ought to be the case. My own feeling is that a human society based simply on the gene's law of universal ruthless selfishness would be a very nasty society in which to live. But unfortunately, however much we may deplore something; it does not stop it being true. This book is mainly intended to be interesting, but if you would extract a moral from it, read it as a warning. Be warned that if you wish, as I do, to build a society in which individuals cooperate generously and unselfishly towards a common good, you can expect little help from biological nature. Let us try to teach generosity and altruism, because we are born selfish. Let us understand what our own selfish genes are up to, because we may then at least have the chance to upset their designs, something that no other species has ever aspired to.

A pesar de esto, existen numerosos casos de colaboración entre animales, tanto dentro de una especie como entre especies, a los cuales la teoría tiene que dar explicación. Para esto Dawkins toma la idea de estrategias evolutivamente estables de John Maynard Smith, .

An evolutionarily stable strategy or ESS is defined as a strategy which, if most members of a population adopt it, cannot be bettered by an alternative strategy. It is a subtle and important idea. Another way of putting it is to say that the best strategy for an individual depends on what the majority of the populations are doing. Since the rest of the population consists of individuals, each one trying to maximize his own success, the only strategy that persists will be one which, once evolved, cannot be bettered by any deviant individual.

An ESS is stable, not because it is particularly good for the individuals participating in it, but simply because it is immune to treachery from within.

Maynard Smith's concept of the ESS will enable us, for the first time, to see clearly how a collection of independent selfish entities can come to resemble a single organized whole. I think this will be true not only of social organizations within species, but also of ‘ecosystems’ and ‘communities’ consisting of many species.

En resumidas cuentas, a través de esta herramienta, Dawkins es capaz de explicar cómo en circunstancias especiales, un gen puede conseguir sus objetivos egoístas favoreciendo un comportamiento altruista a nivel del individuo (la máquina de supervivencia).

El tercer tema, casi de yapa en el libro de Dawkins pero tal vez un disparador más interesante que todo lo anterior, es el concepto de Meme hoy tan popular y acuñado por primera vez en este libro.

Para llegar al Meme, primero es necesario disponer de un cerebro lo suficientemente evolucionado como para admitir un lenguaje y una conciencia. A Dawkins le lleva poco más de tres párrafos llegar a ese punto, y estoy muy conforme porque es el mismo camino que más adelante siguió Dennett en Consciousness Explained, con el que ya fui generoso http://salvettiwr.blogspot.com.ar/2015/01/consciousness-expleined-daniel-dennett.html

The evolution of the capacity to simulate seems to have culminated in subjective consciousness. Why this should have happened is, to me, the most profound mystery facing modern biology. ... Perhaps consciousness arises when the brain's simulation of the world becomes so complete that it must include a model of itself. Obviously the limbs and body of a survival machine must constitute an important part of its simulated world; presumably for the same kind of reason, the simulation itself could be regarded as part of the world to be simulated.

Whatever the philosophical problems raised by consciousness, for the purpose of this story it can be thought of as the culmination of an evolutionary trend towards the emancipation of survival machines as executive decision-takers from their ultimate masters, the genes. Not only are brains in charge of the day-to-day running of survival-machine affairs, they have also acquired the ability to predict the future and act accordingly. They even have the power to rebel against the dictates of the genes.

Genes are the primary policy-makers; brains are the executives. But as brains became more highly developed, they took over more and more of the actual policy decisions, using tricks like learning and simulation in doing so. The logical conclusion to this trend, not yet reached in any species, would be for the genes to give the survival machine a single overall policy instruction: do whatever you think best to keep us alive.

Y esto deja la puerta abierta para retomar el Segundo punto. ¿Es realmente egoísta el hombre en estado de naturaleza? La mejor respuesta es que no importa, porque el hombre está dominado por la cultura, nuestro comportamiento “natural” es totalmente “anti-natural”, o dicho de otra manera, nuestro verdadero comportamiento es un comportamiento cultural.

Among animals, man is uniquely dominated by culture, by influences learned and handed down. Some would say that culture is so important that genes, whether selfish or not, are virtually irrelevant to the understanding of human nature.

Si el hombre es un animal eminentemente cultural, ¿existe alguna forma de evolución que opere a este nivel? Acá es donde Dawkins introduce el concepto de Meme:

Language seems to ‘evolve’ by non-genetic means, and at a rate which is orders of magnitude faster than genetic evolution.

Language is only one example out of many. Fashions in dress and diet, ceremonies and customs, art and architecture, engineering and technology, all evolve in historical time in a way that looks like highly speeded up genetic evolution, but has really nothing to do with genetic evolution.

The new soup is the soup of human culture. We need a name for the new replicator, a noun that conveys the idea of a unit of cultural transmission, or a unit of imitation. ‘Mimeme’ comes from a suitable Greek root, but I want a monosyllable that sounds a bit like ‘gene’. I hope my classicist friends will forgive me if I abbreviate mimeme to meme If it is any consolation, it could alternatively be thought of as being related to ‘memory’, or to the French word meme. It should be pronounced to rhyme with ‘cream’.

Examples of memes are tunes, ideas, catch-phrases, clothes fashions, ways of making pots or of building arches.

Just as genes propagate themselves in the gene pool by leaping from body to body via sperms or eggs, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation.

Si la teoría de la evolución cultural a través de memes es enteramente válida, o simplemente un modelo simple para analizar las formas de difusión cultural es una discusión que todavía no tiene respuesta, pero mientras tanto nos permite evaluar al hombre en términos evolutivos como un ser cultural más que como a una “máquina de supervivencia”. Genéticamente no hay diferencia entre el hombre de las cavernas y nosotros, todas las diferencias son el resultado de la evolución cultural (las buenas y las malas).

It is possible that yet another unique quality of man is a capacity for genuine, disinterested, true altruism. I hope so, but I am not going to argue the case one way or the other, nor to speculate over its possible memic evolution. The point I am making now is that, even if we look on the dark side and assume that individual man is fundamentally selfish, our conscious foresight — our capacity to simulate the future in imagination — could save us from the worst selfish excesses of the blind replicators. We have at least the mental equipment to foster our long-term selfish interests rather than merely our short-term selfish interests.

We have the power to defy the selfish genes of our birth and, if necessary, the selfish memes of our indoctrination. We can even discuss ways of deliberately cultivating and nurturing pure, disinterested altruism — something that has no place in nature, something that has never existed before in the whole history of the world. We are built as gene machines and cultured as meme machines, but we have the power to turn against our creators.

Para terminar, al final del libro, en sus últimas ediciones Dawkins agregó un manifesto que resume muy bien la tesis del gen egoísta, lo dejo para quienes les haya resultado medianamente interesante todo lo anterior.

Let me end with a brief manifesto, a summary of the entire selfish gene/extended phenotype view of life. It is a view, I maintain, that applies to living things everywhere in the universe. The fundamental unit, the prime mover of all life, is the replicator. A replicator is anything in the universe of which copies are made. Replicators come into existence, in the first place, by chance, by the random jostling of smaller particles. Once a replicator has come into existence it is capable of generating an indefinitely large set of copies of itself. No copying process is perfect, however, and the population of replicators comes to include varieties that differ from one another.

Some of these varieties turn out to have lost the power of self-replication, and their kind ceases to exist when they themselves cease to exist. Others can still replicate, but less effectively. Yet other varieties happen to find themselves in possession of new tricks: they turn out to be even better self-replicators than their predecessors and contemporaries. It is their descendants that come to dominate the population. As time goes by, the world becomes filled with the most powerful and ingenious replicators.

Gradually, more and more elaborate ways of being a good replicator are discovered. Replicators survive, not only by virtue of their own intrinsic properties, but by virtue of their consequences on the world. These consequences can be quite indirect. All that is necessary is that eventually the consequences, however tortuous and indirect, feed back and affect the success of the replicator at getting itself copied.

The success that a replicator has in the world will depend on what kind of a world it is — the pre-existing conditions. Among the most important of these conditions will be other replicators and their consequences. Replicators that are mutually beneficial will come to predominate in each other's presence. At some point in the evolution of life on our earth, this ganging up of mutually compatible replicators began to be formalized in the creation of discrete vehicles — cells and, later, many-celled bodies. Vehicles that evolved a bottlenecked life cycle prospered, and became more discrete and vehicle-like.

This packaging of living material into discrete vehicles became such a salient and dominant feature that, when biologists arrived on the scene and started asking questions about life, their questions were mostly about vehicles — individual organisms. The individual organism came first in the biologist's consciousness, while the replicators — now known as genes — were seen as part of the machinery used by individual organisms. It requires a deliberate mental effort to turn biology the right way up again, and remind ourselves that the replicators come first, in importance as well as in history.

One way to remind ourselves is to reflect that, even today, not all the phenotypic effects of a gene are bound up in the individual body in which it sits. Certainly in principle, and also in fact, the gene reaches out through the individual body wall and manipulates objects in the world outside, some of them inanimate, some of them other living beings, some of them a long way away. With only a little imagination we can see the gene as sitting at the center of a radiating web of extended phenotypic power. And an object in the world is the center of a converging web of influences from many genes sitting in many organisms. The long reach of the gene knows no obvious boundaries. The whole world is crisscrossed with causal arrows joining genes to phenotypic effects, far and near.

It is an additional fact, too important in practice to be called incidental but not necessary enough in theory to be called inevitable, that these causal arrows have become bundled up. Replicators are no longer peppered freely through the sea; they are packaged in huge colonies — individual bodies. And phenotypic consequences, instead of being evenly distributed throughout the world, have in many cases congealed into those same bodies. But the individual body, so familiar to us on our planet, did not have to exist. The only kind of entity that has to exist in order for life to arise, anywhere in the universe, is the immortal replicator.