Re: [escepticos] Diferencias geneticas (era: entre los sexos)

[Daneel Olivaw <radial@...>]

Marmitako wrote:

> Meto tambien vela en este entierro
> 
> Creo que la constancia de la proporcion de zurdos durante miles de anyos
> dificilmente es un argumento. Lo primero, no se de donde salen los datos
> del porcentaje de zurdos en tiempos de Herodes. Dudo que llevaran un
> registro muy riguroso. Lo segundo, que si asi fuera y efectivamente se
> ha mantenido constante, seria mas un argumento en favor de la no
> heredabilidad que de la determinacion genetica. 

Bueno, Marmi, como sabes no soy un experto en genética y tu razonamiento
ya me lo habían explicado otra vez. Pero ellos siguen erre que erre y la
base es la siguiente (una crítica por tu parte sería bienvenida,
teniendo en cuenta que nos movemos en el terreno de la especulación):


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Proc R Soc Lond B Biol Sci 1996 Dec 22;263(1377):1627-1633 

Frequency-dependent maintenance of left handedness in humans.

Raymond M, Pontier D, Dufour AB, Moller AP

Equipe Genetique et Environment, Institut des Sciences de l'Evolution
(UMR CNRS 5554), Universite de Monlpellier II, France. 

The percentage (10-13%) of left handedness in human has apparently not
changed since the Neolithic. Left handedness is heritable and
appears to be repeatedly associated with some reduced fitness
components; the persistence of left handedness implies that left handers
have a fitness advantage in some situations. We propose that left
handers have a frequency-dependent advantage in fights and for that
reason a fitness advantage. To test this hypothesis, left handedness
frequencies in the general population and in sporting individuals
(both students and the sporting elite) have been compared, as sporting
performance is likely to be a good indicator of fighting abilities.
The higher proportion of left-handed individuals in interactive sports
(reflecting some fighting elements), reaching 50% in some sports
categories, but not in noninteractive sports, is consistent with the
fighting hypothesis. The greater frequency of left handedness in males
than in females is also consistent with this hypothesis, as male-male
fights are universally more frequent than other combinations. The
frequency-dependent advantage in fights of left handers might explain
the stability of left handedness. 
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Saludos.

Daneel.