How women evolved blond hair to win cavemen's hearts
For those who are still considering the debate on whether men prefer blondes, a study may have provided proof in favour of the flaxen-haired, if only because they appeal to the "caveman" within.
Academic researchers have discovered that women in northern Europe evolved with light hair and blue eyes at the end of the Ice Age to stand out from the crowd and lure men away from the far more common brunette.
Blond hair originated through genetic necessity at a time when there was a shortage of both food and males, leading to a high ratio of women competing for smaller numbers of potential partners, according to the study published this week in the academic journal, Evolution and Human Behaviour.
Until these shortages about 10,000 to 11,000 years ago, humans had uniformly dark hair and eyes.
http://www.independent.co.uk/news/science/how-women-evolved-blond-hair-to-win-cavemens-hearts-467901.html
xchrom
(108,903 posts)Ecumenist
(6,086 posts)large are RANDOM. What this person was postulating makes about as much sense as a mud window.
dipsydoodle
(42,239 posts)So you don't think there's an association between environmental changes and genetic changes at all ?
How come then for example are we not all black ?
Evolution of blond hair
Natural lighter hair colors occur most often in Europe and less frequently in other areas.[22] In northern European populations, the occurrence of blond hair is very frequent. The hair color gene MC1R has at least seven variants in Europe giving the continent a wide range of hair and eye shades. Based on recent genetic research carried out at three Japanese universities, the date of the genetic mutation that resulted in blond hair in Europe has been isolated to about 11,000 years ago during the last ice age.[23]
A typical explanation found in the scientific literature for the evolution of light hair is related to the requirement for vitamin D synthesis and northern Europe's seasonal deficiency of sunlight.[24] Lighter skin is due to a low concentration in pigmentation, thus allowing more sunlight to trigger the production of vitamin D. In this way, high frequencies of light hair in northern latitudes are a result of the light skin adaptation to lower levels of sunlight, which reduces the prevalence of rickets caused by vitamin D deficiency. The darker pigmentation at higher latitudes in certain ethnic groups such as the Inuit is explained by a greater proportion of seafood in their diet. As seafood is high in vitamin D, vitamin D deficiency would not create a selective pressure for lighter pigmentation in that population.
Blond children in Afghanistan
An alternative hypothesis was presented by Canadian anthropologist Peter Frost, under the aegis of University of St Andrews, who published a study in March 2006 in the journal Evolution and Human Behavior. Frost said blond hair evolved very quickly in a specific area at the end of the last ice age by means of sexual selection.[25] According to the study, the appearance of blond hair and blue eyes in some northern European women made them stand out from their rivals at a time of fierce competition for scarce males. The study argues that blond hair was produced higher in the Cro-Magnon descended population of the European region because of food shortages 10,000-11,000 years ago following the last glacial period when most of it was covered by steppe-tundra. Almost the only sustenance in northern Europe came from roaming herds of mammoths, reindeer, bison and horses and finding them required long, arduous hunting trips in which numerous males died, leading to a high ratio of surviving women to men. This hypothesis argues that women with blond hair posed an alternative that helped them mate and thus increased the number of blonds.[26]
A theory propounded in The History and Geography of Human Genes (1994), says blond hair became predominant in Northern Europe beginning about 3,000 BC, in the area now known as Lithuania, among the recently arrived Proto-Indo-European settlers (according to the Kurgan hypothesis), and the trait spread quickly through sexual selection into Scandinavia. As above, the theory assumes that men found women with blond hair more attractive.[27]
http://en.wikipedia.org/wiki/Blond#Evolution_of_blond_hair
seabeyond
(110,159 posts)Mosaic
(1,451 posts)I was married to two Asians, I always found them most beautiful.
seabeyond
(110,159 posts)the men just cause
that is so stupid
4th law of robotics
(6,801 posts)In humans and other species.
That's why men on average are larger and more muscular than women (even though this isn't true in all species or even most).
Or why peacocks are a bit differently colored than peahens.
SATIRical
(261 posts)are closely tied.
So you are saying that if a black woman and white man have kids, the girls will be black and the boys white?
It doesn't work that way for skin or hair.
gordianot
(15,223 posts)This occurs in many different skin tones.
dipsydoodle
(42,239 posts)Good ol' Reginald D, Hunter.
Cleita
(75,480 posts)that Europeans have some neanderthal genes in them.
Gman
(24,780 posts)The most likely explanation to me has always been the adaptation to long nights and short days in northern Europe and elsewhere north of the 40th parallel where the body did not require as much melanin to protect against the sun's rays, given that humans first evolved out of the much lower latitudes of Africa where melanin was much more vital.
4th law of robotics
(6,801 posts)you can be very pale and have very dark features.
Likewise there really is no advantage to having blue eyes (other than appearance) because it offers no advantage in areas with low solar activity and can lead to greater rates of cataracts in brighter areas.
Gman
(24,780 posts)and dark hair does provide protection from the sun as it is usually much thicker than blonde hair. The scalp is one of the most sensitive areas of the body's skin.
Nikia
(11,411 posts)So that blue eyed people could see better at night and in the between time as well as caves and dense forest.
Cleita
(75,480 posts)I think you just hit on the evolutionary advantage of lighter colored eyes.
varelse
(4,062 posts)We also need Vitamin D to live, and our bodies require UV light (sunlight) to make it.
http://www.sciencedirect.com/science/article/pii/S1011134406002491
Tom Ripley
(4,945 posts)this nonsense
NOLALady
(4,003 posts)Due to the shortage of men, women had to compete. I'm certain the cavemen were monogamous.
Fumesucker
(45,851 posts)LiberalEsto
(22,845 posts)It would never OCCUR to the man-centric research community that blond hair might have evolved simply because of an accidental genetic mutation. And/or because of differences in the amount of sunlight exposure. Or some other factor that hasn't yet been recognized.
How can a blond woman possibly stand out in a crowd of other blond people?
Igel
(35,173 posts)And then there's "spread."
The point mutations would pop up randomly. They'd only survive and spread if they were were selected for.
HereSince1628
(36,063 posts)Attributing intention/purpose to the origin of a mutation...that's fairly shakey and I hope the authors of the study actually didn't do that.
Sexual selection that biases benefits to one sex often produces asymmetry on the trait being influenced (large body size for one sex, larger horns or antlers on one sex, longer tails on one sex, flashier colors on one sex, bigger breasts on one sex, etc). Natural blondness shows up in both sexes, pretty much equally.
Absent a variation between sexes it seems that this speculation of value of this trait to women would require some strong evidence that females had some operational mechanism that actually led to an advantage and that should come from the a time before hair bleach.
One of the peculiar asymmetries of blondness isn't about sex, it's about age. Pre-pubescent blonde children often have very pale hair. I would think any hypothesis surrounding the fitness of blondness would need to deal with the pattern of changes in shading of blonde hair with age.
bemildred
(90,061 posts)The best one can say about this is its "plausible" if you don't look too close.
Also, us caucasoids tend to darken as we age, so light coloration is an indicator of neoteny, youth, and young women make the best mothers, especially if Dad cannot be expected to do much to help.
longship
(40,416 posts)John McCain - check
Newt Gingrich (after third try) - check
Willard Rmoney - check
Rush Limpballs (how many before he got it right?) - check
I guess Santorum is the outlier. No wonder he did so bad. Don't get me started on the non-blond Michelle Bachmann.
The knuckledraggers prefer blondes.
cpwm17
(3,829 posts)This is a more speculative theory, but I'm inclined to believe it. Blond hair represents youth since children are often born with lighter hair. A blond woman looks younger, plus she would stand out in a crowd. A harsh environment would put strong evolutionary pressures for this sexual selection.
Also the different hair colors give men and woman more choices, which pushes the evolution of different hair colors - including red. Some northern European men and woman still like darker hair, and dark hair still exists in northern Europe - even when they have light skin for vitamin D production.
muriel_volestrangler
(101,083 posts)2
: sexual excitement
http://www.merriam-webster.com/dictionary/ardor
They loved hunting so much it killed them? Or they died from sexual over-excitement?
The writer means "arduousness". Just because something's 'ard, it doesn't mean you need ardour.
dipsydoodle
(42,239 posts)philly_bob
(2,418 posts)bemildred
(90,061 posts)People with blue eyes have a single, common ancestor, according to new research.
A team of scientists has tracked down a genetic mutation that leads to blue eyes. The mutation occurred between 6,000 and 10,000 years ago. Before then, there were no blue eyes.
"Originally, we all had brown eyes," said Hans Eiberg from the Department of Cellular and Molecular Medicine at the University of Copenhagen.
The mutation affected the so-called OCA2 gene, which is involved in the production of melanin, the pigment that gives color to our hair, eyes and skin.
http://www.livescience.com/9578-common-ancestor-blue-eyes.html
dipsydoodle
(42,239 posts)and I agree with your vit D comment above too.
bemildred
(90,061 posts)You have this fortuitous mutation, recessive I believe, since blue eyes are, and it spreads like mad in certain parts of the globe. You can't tell me it's just because we are cute, and as other posters mentioned, it has drawbacks. Furthermore, there are plenty of people living at high latitudes without it, who seem to have done some amazing things themselves.
I can justify light hair on the same basis as light skin, it let's more light through, but the eyes? Nope. Must be something else going on.
Edit: further, the traits are all separate, can and do occur separately.
dipsydoodle
(42,239 posts)apart from Crystal Gayle and Bob Dylan to sing about quite aside from the Carter Family - obligatory link to follow. Give it some Maybelle.
Ive got blue eyes : never given them much thought. They work which is all that really matters.
bemildred
(90,061 posts)Odin2005
(53,521 posts)The sexism reeks.
rug
(82,333 posts)4th law of robotics
(6,801 posts)dipsydoodle
(42,239 posts)treestar
(82,383 posts)This just can't be so.
Lydia Leftcoast
(48,217 posts)women have their breasts out front because "it's more attractive to the male." Yes, I've actually seen that claimed in a pop science article.
I've long noticed that blond hair and light skin occur in precisely the areas where the Neanderthals lived, not anywhere else. Could it be that these genes entered the human genome through interbreeding with Neanderthals and conferred an evolutionary advantage, since the average blond is lighter skinned than the average brunette and therefore better able to absorb Vitamin D.
The part about all blue-eyed people descending from a single ancestor is amazing, especially since blue eyes are a recessive trait. There must have been a lot of family "closeness" going on to spread that trait initially, if you know what I mean.