La selección natural, agente mejorador, idea fundamental del darwinismo
Corrí hasta el quiosco de periódicos más cercano y busqué todo lo que había sobre la crisis petrolera y los peligros de la energía nuclear. Acababa de decidir comprar un billete aéreo para ir a Nueva York.
-Vaya mundo en el que vivimos, ¿verdad? -el propietario era un negro delgado de mala dentadura y evidente peluca. Asentí, buscando monedas en los bolsillos del pantalón, deseando encontrar un banco de parque donde poder sumergirme en la dura evidencia de la casi distopía humana en que vivimos-.
– Pero podría ser peor, ¿verdad?
-Así es -dije-, o peor aún, podría ser perfecto.
El hombre se quedó mirándome mientras me alejaba por la calle con mi pequeño fajo de catástrofes condensadas.
W. Gibson. El contínuo de Gernsback
**********************************************************************************
Por encima de los doce o catorce significados diferentes que Darwin da en su obra principal a la Selección Natural (causa de extinción, medio de modificación, proceso general, agente, poder o fuerza, preservación de caracteres, expresión de la bondad, agente y modificador autorizado, supervivencia del más apto, etcétera) y también por encima de la otra docena de significados adicionales que han venido dando los darwinistas a lo largo de la historia (ley, hipótesis, teoría, explicación, teorema, mecanismo, diseño sin diseñador); pues bien, digo: por encima de todo ello planea otro significado de índole principal…..
Encontramos en la obra de Darwin una idea fundamental. En lo más alto y por encima de estos veintitantos significados diferentes yace oculta la clave de todo el darwinismo: el profundo y más verdadero significado del término Selección Natural ¿Cuál?
Iva Mendes lo describía hace poco en su blog humor darwinista en una entrada titulada en portugués “Seleção Natural como agente aperfeiçoador”.
Muchos son los párrafos de la obra capital de Darwin en los que se expresa esta idea de la Selección Natural como Agente Perfeccionador o en español, Agente Mejorador.
Una treintena de tales párrafos se muestran en la referida entrada del blog Humor Darwinista. Todos contienen las palabras aperfeiçoar, aperfeiçoamento , aperfeiçoadas y relativas, con jugosos comentarios en portugués. La traducción de improve (d) del original inglés al español, mejorar (mejorado,s) da idea de cuánto se parece para Darwin la Naturaleza a una granja y de paso nos acerca a un tema delicado y que deberá ser objeto de un análisis detallado, pero cuya descripción apenas ha hecho sino empezar: El escaso o nulo respeto del darwinismo por la Naturaleza.
Todos los ejemplos que aquí siguen proceden el Capítulo cuarto de la obra, precisamente titulado NATURAL SELECTION; OR THE SURVIVAL OF THE FITTEST del que destacamos algunos párrafos que en su versión original en inglés, ponen bien de manifiesto este meta-significado de transcendental importancia: Hay algo en la Naturaleza, un no-sé-qué, una meta-fuerza que tiene esa finalidad de mejorarla constantemente: La Selección Natural.
Ejemplo 1:
This preservation of favourable individual differences and variations, and the destruction of those which are injurious, I have called Natural Selection, or the Survival of the Fittest. Variations neither useful nor injurious would not be affected by natural selection, and would be left either a fluctuating element, as perhaps we see in certain polymorphic species, or would ultimately become fixed, owing to the nature of the organism and the nature of the conditions.
Ejemplo 2:
In such cases, slight modifications, which in any way favoured the individuals of any species, by better adapting them to their altered conditions, would tend to be preserved; and natural selection would have free scope for the work of improvement.
Ejemplo 3:
As man can produce, and certainly has produced, a great result by his methodical and unconscious means of selection, what may not natural selection effect? Man can act only on external and visible characters: Nature, if I may be allowed to personify the natural preservation or survival of the fittest, cares nothing for appearances, except in so far as they are useful to any being.
Ejemplo 4:
It may metaphorically be said that natural selection is daily and hourly scrutinising, throughout the world, the slightest variations; rejecting those that are bad, preserving and adding up all that are good; silently and insensibly working, WHENEVER AND WHEREVER OPPORTUNITY OFFERS, at the improvement of each organic being in relation to its organic and inorganic conditions of life.
Ejemplo 5
Although natural selection can act only through and for the good of each being, yet characters and structures, which we are apt to consider as of very trifling importance, may thus be acted on
Ejemplo 6
Hence natural selection might be effective in giving the proper colour to each kind of grouse, and in keeping that colour, when once acquired, true and constant.
Ejemplo 7
so in a state of nature natural selection will be enabled to act on and modify organic beings at any age, by the accumulation of variations profitable at that age, and by their inheritance at a corresponding age……….
Ejemplo 8
So, conversely, modifications in the adult may affect the structure of the larva; but in all cases natural selection will ensure that they shall not be injurious: for if they were so, the species would become extinct.
Ejemplo 9
Natural selection will modify the structure of the young in relation to the parent and of the parent in relation to the young. In social animals it will adapt the structure of each individual for the benefit of the whole community
Ejemplo 10
A structure used only once in an animal’s life, if of high importance to it, might be modified to any extent by natural selection;
Ejemplo 11
Natural selection acts only by the preservation and accumulation of small inherited modifications, each profitable to the preserved being; and as modern geology has almost banished such views as the excavation of a great valley by a single diluvial wave, so will natural selection banish the belief of the continued creation of new organic beings, or of any great and sudden modification in their structure.
Ejemplo 12
and through natural selection which will destroy any individuals departing from the proper type.
Ejemplo 13
If the conditions of life change and the form undergoes modification, uniformity of character can be given to the modified offspring, solely by natural selection preserving similar favourable variations.
Ejemplo 14
and again there will have been a fair field for natural selection to improve still further the inhabitants, and thus to produce new species.
Ejemplo 15
I think it inevitably follows, that as new species in the course of time are formed through natural selection, others will become rarer and rarer, and finally extinct.
Ejemplo 16
As in each fully stocked country natural selection necessarily acts by the selected form having some advantage in the struggle for life over other forms, there will be a constant tendency in the improved descendants of any one species to supplant and exterminate in each stage of descent their predecessors and their original progenitor.
Ejemplo 17
for as natural selection acts through one form having some advantage over other forms in the struggle for existence
Ejemplo 18
Natural selection acts exclusively by the preservation and accumulation of variations, which are beneficial under the organic and inorganic conditions to which each creature is exposed at all periods of life
Ejemplo 19
natural selection clearly leads towards this standard: for all physiologists admit that the specialisation of organs, inasmuch as in this state they perform their functions better, is an advantage to each being; and hence the accumulation of variations tending towards specialisation is within the scope of natural selection
Ejemplo 20
it is quite possible for natural selection gradually to fit a being to a situation in which several organs would be superfluous or useless
Ejemplo 21
On our theory the continued existence of lowly organisms offers no difficulty; for natural selection, or the survival of the fittest, does not necessarily include progressive development–it only takes advantage of such variations as arise and are beneficial to each creature under its complex relations of life.
Ejemplo 22
If it were no advantage, these forms would be left, by natural selection, unimproved or but little improved, and might remain for indefinite ages in their present lowly condition.
Ejemplo 23
In some cases variations or individual differences of a favourable nature may never have arisen for natural selection to act on and accumulate.
Ejemplo 24
This preservation of favourable individual differences and variations, and the destruction of those which are injurious, I have called Natural Selection, or the Survival of the Fittest
Y finalmente la última que indiscutiblemente da sentido al lote:
Ejemplo 25
And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress towards perfection.
Para Darwin y el darwinismo, la Naturaleza es una granja. Podríamos pensar que el granjero está de vacaciones y que todo mejora paulatinamente por acción de la Selección Natural. Libre de toda vigilancia, la Selección Natural obra para el mejoramiento de todos los seres. Si surge un problema, entonces mejor, toda dificultad será tomada como prueba a favor de la Selección Natural. Por ejemplo si en las series de fósiles no hay formas de transición, eso será la prueba de su existencia: Credo quia absurdum, ¿Les suena?
El profesor Thompson lo explicaba asi de bien:
Darwin did not show in the Origin that species had originated by natural selection; he merely showed, on the basis of certain facts and assumptions, how this might have happened, and as he had convinced himself he was able to convince others.
Referencias
Darwin, Charles. On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. Sexta edición en Project Gutenberg.
Thompson, W.R., «Introduction,» in Darwin C.R., «The Origin of Species by Means of Natural Selection,» Sixth Edition, 1872, Everyman’s Library, J.M. Dent & Sons: London, 1967, reprint, p.xi.
Bibliografía (sin peligro de extinción por el momento)
On the Origin of Species By Means of Natural Selection, or, the Preservation of Favoured Races in the Struggle for Life. Sexta edición en biblioteca Gutenberg.
http://www.gutenberg.org/files/2009/2009.txt
Imagen tomada de Flickr