Happy Roodharigendag (that's Redhead Day in Dutch). It's a summer festival that takes place the first weekend in September in the Netherlands. This year, nearly 5,000 people gathered to celebrate all things fiery red, especially this unique phenotype.
But what exactly is the genetic story behind red hair? How do redheads get that auburn tone? And does their rumored extinction have any actual scientific backing?
Click the link below and watch the video above to find out. And don't forget to sound off in the comments section below. Come on, talk nerdy to me!
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Hi everyone. Cara Santa Maria here. I heard the other day that people with red hair are going extinct. Then I looked it up online, and wouldn't you know, there it was, all over the place: the great demise of the redhead. Luckily, we don't believe everything we see on the Internet. (More on that later...)
How do redheads get that coppery tone? Melanin. It's a pigment found in human skin and hair that gives it color. It's made by special cells appropriately called melanocytes. We all have them, but some people's produce more melanin than others. Like people with albinism: they produce little or none. Biologically speaking, and I say this with love, of course, redheads are mutants. See, melanocytes have a special receptor on them that tells them to produce a certain kind of melanin. It's called the melanocortin-1 receptor, and in redheads, it doesn't work properly.
Fair skin and freckles are hallmarks of redheadedness. But with those unique signs of beauty comes an increased risk of developing skin cancer. And strangely, research has suggested that that women with red hair require higher doses of anesthesia. But a recently published study by a team of Australian scientists suggests no significant effect of hair color on anesthetic requirements or overall patient recovery. Clearly, more research is needed to get to the bottom of this. Because even though red is the rarest hair color on earth, there are still a fair amount of redheads out there.
Although estimates vary, the number is likely less than 1 percent of the world population. But nearly one-tenth of the Irish population has red hair, and in Scotland, it's nearly 13 percent. Nobody knows exactly when the first red haired humans came on the scene, but it may have been a relatively recent arrival--between 20 and 40 thousand years ago. And even older hominins--neanderthals, to be exact--probably had red hair too, although it came from a completely different gene variant. When that happens it's called convergent evolution, like how bats and birds both developed wings, but through completely different evolutionary processes.
As I said earlier, having red hair is usually caused by a mutation. And this mutation is passed down recessively. That means that both of your parents have to carry the recessive gene for you to have a chance of having red hair. Two redheads make a redhead, but so can two brunettes, as long as they're both carrying that mutated gene. And only about 4 percent of the overall population does.
This brings us back to whether or not redheads may be going extinct. Well, if you think back really hard to your high school biology class---oh who am I kidding? The answer is no! The more we travel around and mix our genes in this giant melting pot, the more diluted that redhead gene variant will become. But recessive traits don't get bred out of a population. Genetics doesn't work that way. Recessive genes are tricky--they hide behind their dominant counterparts. So don't you worry redheads, you are not the last of a dying breed.
Redheads, sound off! Reach out on Twitter, Facebook, or leave a comment right here on the Huffington Post. Come on, talk nerdy to me!
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Also on HuffPost:
Glow-in-the-dark cats
In 2007, South Korean scientists altered a cat’s DNA to make it glow in the dark and then took that DNA and cloned other cats from it — creating a set of fluffy, <a href="http://cosmiclog.msnbc.msn.com/_news/2007/12/13/4349719-cloned-cats-that-glow" target="_hplink">fluorescent felines</a>. Here’s how they did it: The researchers took skin cells from Turkish Angora female cats and used a virus to insert genetic instructions for making red fluorescent protein. Then they put the gene-altered nuclei into the eggs for cloning, and the cloned embryos were implanted back into the donor cats — making the cats the surrogate mothers for their own clones. What’s the point of creating a pet that doubles as a nightlight? Scientists say the ability to engineer animals with fluorescent proteins will enable them to artificially create animals with human genetic diseases.
Enviropig
The <a href="http://news.nationalgeographic.com/news/2010/03/100330-bacon-pigs-enviropig-dead-http://news.nationalgeographic.com/news/2010/03/100330-bacon-pigs-enviropig-dead-zones/" target="_hplink">Enviropig</a>, or “Frankenswine,” as critics call it, is a pig that’s been genetically altered to better digest and process phosphorus. Pig manure is high in phytate, a form of phosphorus, so when farmers use the manure as fertilizer, the chemical enters the watershed and causes algae blooms that deplete oxygen in the water and kill marine life. So scientists added an E. Coli bacteria and mouse DNA to a pig embryo. This modification decreases a pig’s phosphorous output by as much as 70 percent — making the pig more environmentally friendly.
Pollution-fighting plants
Scientists at the University of <a href="http://www.mnn.com/local-reports/washington" target="_hplink">Washington</a> are <a href="http://wa.water.usgs.gov/pubs/fs/fs082-98/" target="_hplink">engineering poplar trees that can clean up contamination sites</a> by absorbing groundwater pollutants through their roots. The plants then break the pollutants down into harmless byproducts that are incorporated into their roots, stems and leaves or released into the air. In laboratory tests, the transgenic plants are able to remove as much as 91 percent of trichloroethylene — the most common groundwater contaminant at U.S. Superfund sites — out of a liquid solution. Regular poplar plants removed just 3 percent of the contaminant.
Venomous cabbage
Scientists have recently taken the gene that programs poison in scorpion tails and combined it with cabbage. Why would they want to create <a href="http://www.nature.com/cr/journal/v12/n2/full/7290120a.html" target="_hplink">venomous cabbage</a>? To limit pesticide use while still preventing caterpillars from damaging cabbage crops. These genetically modified cabbages produce scorpion poison that kills caterpillars when they bite leaves — but the toxin is modified so it isn’t harmful to humans.
Web-spinning goats
Strong, flexible spider silk is one of the most valuable materials in nature, and it could be used to make an array of products — from artificial ligaments to parachute cords — if we could just produce it on a commercial scale. In 2000, Nexia Biotechnologies announced it had the answer: <a href="http://www.physorg.com/news194539934.html" target="_hplink">a goat that produced spiders’ web protein</a> in its milk. Researchers inserted a spiders’ dragline silk gene into the goats’ DNA in such a way that the goats would make the silk protein only in their milk. This “silk milk” could then be used to manufacture a web-like material called Biosteel.
Fast-growing salmon
AquaBounty’s genetically modified salmon grows twice as fast as the conventional variety — the photo shows two same-age salmon with the genetically altered one in the rear. The company says the fish has the same flavor, texture, color and odor as a regular salmon; however, the debate continues over whether the fish is safe to eat. <a href="http://www.aquabounty.com/products/products-295.aspx" target="_hplink">Genetically engineered Atlantic salmon</a> has an added growth hormone from a Chinook salmon that allows the fish to produce growth hormone year-round. Scientists were able to keep the hormone active by using a gene from an eel-like fish called an ocean pout, which acts as an “on switch” for the hormone. If the FDA approves the sale of the salmon, it will be the first time the government has allowed modified animals to be marketed for human consumption. According to federal guidelines, the fish would not have to be labeled as genetically modified.
Flavr Savr tomato
The <a href="http://californiaagriculture.ucanr.org/landingpage.cfm?article=ca.v054n04p6&fulltext=yes" target="_hplink">Flavr Savr tomato</a> was the first commercially grown genetically engineered food to be granted a license for human consumption. By adding an antisense gene, the <a href="http://www.mnn.com/local-reports/california" target="_hplink">California</a>-based company Calgene hoped to slow the ripening process of the tomato to prevent softening and rotting, while allowing the tomato to retain its natural flavor and color. The FDA approved the Flavr Savr in 1994; however, the tomatoes were so delicate that they were difficult to transport, and they were off the market by 1997. On top of production and shipping problems, the tomatoes were also reported to have a very bland taste: “The Flavr Savr tomatoes didn’t taste that good because of the variety from which they were developed. There was very little flavor to save,” said Christ Watkins, a horticulture professor at Cornell University.
<a href="http://www.mnn.com/green-tech/research-innovations/photos/12-bizarre-examples-of-genetic-engineering/banana-vaccines" target="_hplink"><strong>CLICK HERE</strong></a> to continue on to <a href="http://www.mnn.com" target="_hplink">Mother Nature Network</a> to see the rest of these bizarre genetically engineered creations, including <a href="http://www.mnn.com/green-tech/research-innovations/photos/12-bizarre-examples-of-genetic-engineering/banana-vaccines" target="_hplink">banana vaccines</a>, <a href="http://www.mnn.com/green-tech/research-innovations/photos/12-bizarre-examples-of-genetic-engineering/less-flatulent-cow" target="_hplink">less-flatulent cows</a>, <a href="http://www.mnn.com/green-tech/research-innovations/photos/12-bizarre-examples-of-genetic-engineering/medicinal-eggs" target="_hplink">medicinal eggs</a> and more!
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Posted: 09/13/2012 8:21 am Updated: 09/14/2012 5:56 am