"neither positive nor negative" - my arse!
'Eiberg noted that the blue eyes mutation is neither "positive nor negative", since it doesn't affect chances of survival.'
I've noted the opposite - hasn't he noticed the conspicuous variation of distribution of the trait according to latitude?
I remember, some time ago, reading a fascinating and compelling hypothesis about a possible reason for there being so many gingers up north.
If memory serves, Scottish types studied and found to have a far greater than normal frequency of the MC1R mutation - which results in their ruddy colouring. The MC1R mutation for red hair seems uncannily similar to the OCA2 mutation which produces blue eyes. Both are mutations of genes involved in melatonin pigmentation, both mutations result in a reduction of pigmentation (individuals exhibiting both traits are considered "fair" - less skin pigmentation and more susceptible to sunburn), both mutations are recessive, the presence of a twin set of either mutated gene is betrayed by an obvious (though possibly less significant) physical trait (hair or eye colour).
The theory goes that because the fairer skin of individuals exhibiting traits of the MC1R mutation (I'm extrapolating this to OCA2 too) will tan less quickly/deeply when exposed to the precious few hours of sunshine they get up north, therefore they will produce more vitamin D during the summer. That extra vitamin D can be stored into the gloomy winter and help fend off the ravages of Rickets etc. So, if you live somewhere with a shitty climate, having fairer skin which tans poorly gives you a huge evolutionary advantage - blue eyes and red hair will proliferate. Conversely, if you live in the baking sun you'd be burnt to a crisp - blue eyes and red hair will die out.
It seems silly to muse that the mutation is "neither positive nor negative". ...and this is before you factor in any subjective effects such as attractiveness. I for one have a real weakness for blue eyed brunettes and welcome our new D enriched overloards.
Paris because of her apparent Nordic colouring.