[escepticos] Genoma y cultura

[Francisco Perfectti]

Saludos Corrala:

No suelo participar por falta de tiempo que no de interés, pero sobre
este tema tengo algo de información.

Resulta que se van acumulando indicios de la coevolución cultura-genes
en el linaje humano. Y esto no es en absoluto descabellado. El ambiente
donde nos movemos es una ambiente modificado por la cultura y parece que
ha habido selección adaptativa de ajuste a este ambiente. Esta selección
ha dejado su huella en nuestro genoma.

Hace un año se publicó una revisión sobre el tema:

Laland et al. (2010)
How culture shaped the human genome: bringing genetics and the human
sciences together
Nature Review Genetics 11: 137-149
Accesible a través de:  http://lalandlab.st-andrews.ac.uk/


Un resumen:

A variety of researchers are converging on the view that human evo-
lution has been shaped by gene–culture interactions. Theoretical
biologists use models to demonstrate that cultural processes can
affect human evolution, anthropologists are investigating cultural
practices that modify current selection, and geneticists are uncov-
ering alleles that have been subject to recent selection because of
human activities.
-Theoretical population genetics models are used to explore how
genes and culture interact over evolutionary time, including how
and why culture can affect evolutionary rates.
-Niche-construction theory is a branch of evolutionary biology that
emphasizes the capacity of organisms to modify natural selection
and thereby act as co-directors of their own, and other species’, evo-
lution. Humans are the ultimate niche-constructing species. We
specify how variation in buffering through cultural niche construc-
tion could explain geographical variation in human genes.
-A further source of evidence for gene–culture co-evolution comes from
anthropological studies of contemporary human populations,
which demonstrate gene–culture co-evolution in action. Examples
include Kwa-speaking yam cultivators in West Africa whose agri-
culture favoured the haemoglobin S (HbS) ‘sickle-cell’ allele, and
Polynesian voyages that led to positive selection for thrifty metabo-
lism, leading to type 2 diabetes susceptibility.
-Geneticists have recently developed methods to identify alleles that
have been favoured by recent selection, many of which seem to
have been favoured because of cultural activities. Overrepresented
categories of genes that have been subject to positive selection
include those related to recent changes in human diet and human-
induced disease.
-The well-researched example of co-evolution of dairy farming and
the lactase gene shows the range of methods used to investigate
gene–culture co-evolution.
-We end by asking how prevalent gene–culture co-evolution is, and
how researchers can differentiate between a molecular signature of
selection generated by gene–culture co-evolution and one gener-
ated from a non-cultural aspect of the environment.




Así que la frase de Damasio no parece incorrecta, aunque quizás lo de
que "ocasionan cambios en el genoma" suene un poco exagerado. Aunque no
creo que se refiera a que produce mutaciones, sino que la coevolución
con la cultura deja su huella en el genoma.


Saludos de nuevo
F. Perfectti





> Hola, JM:
> 
> [Jaime]
> >> >> En su último libro (*Y el cerebro creó al hombre*) Antonio Damasio dice:
> >> >>
> >> >> «Cada día aumenta el número de pruebas que indican que a lo largo de
> >> >> múltiples generaciones los avances culturales ocasionan cambios en el
> >> >> genoma».
> 
> [JM Mulet]
> > No me he leido el libro, ni conozco al antonio damasio, pero tal cual esta
> > escrita la frase, esta mal.
> 
> [Jaime]
> Antonio Damasio es un reconocido neurocientífico y, en realidad, saqué
> a colación esta frase porque, de entrada, no me sonó nada bien y, como
> mis conocimientos sobre el tema son bien escasos, quería saber qué
> opinaba la corrala. Es posible, también, que sea un problema de
> traducción.
> 
> 
> Saludos,
> 
> Jaime Rudas
> Bogotá
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