Unraveling the History of Human Hair

iStock/ValuaVitaly
iStock/ValuaVitaly

Be it brown or blond, in a straight or naturally curly hair style, the hair that grows from our heads is a fundamental aspect of the human appearance. Our multitude of hair types is so ubiquitous that it’s actually easy to ignore how weird hair is—and not in the sense that your hair style might be on the wrong side of edgy.

“When it comes to human uniqueness, people come up with all kinds of stuff—culture, intelligence, language,” Tina Lasisi, a doctoral candidate in anthropology at Penn State University, tells Mental Floss. “[But] we’re the only mammals that have hairless bodies and hairy scalps.”

On the surface, our hair types are simple enough. Like fingernails, hair is made mostly of the protein keratin. It can survive for millennia under the right conditions—think Ötzi, the 5300-year-old iceman whose clothing, body, and hair were all preserved when he was frozen in a glacier. In warmer, wetter, more acidic environments, hair can degrade within weeks.

But that’s only what hair is. Why we have different hair types and how they came to be is a mystery that scientists are just now beginning to untangle.

Why Do We Have Hair on Our Heads?

Mother holding child with a braided hairstyle
iStock/Kali9

Some researchers have tried on various hypotheses to explain the patterns of hair growth in Homo sapiens and why they differ so dramatically from our close relatives, like chimpanzees. Losing body hair meant we could sweat more, a cooling mechanism that “helped to make possible the dramatic enlargement of our most temperature-sensitive organ, the brain,” writes anthropologist Nina Jablonski in Scientific American. Other researchers hypothesized that the hair remaining on human heads helped hominins regulate body temperature when they became bipedal and started traveling long distances. Basically, scalp hair created a kind of built-in hat.

Hair doesn’t usually stick around for hundreds of thousands of years the way fossilized bones do. If scientists want to answer the question of how our hair evolved from full-body fur, they have to explore the human genome—and Lasisi found that surprisingly few have done so. That’s partially because of the time and expense of conducting genomic analysis to pinpoint which genes affect the production of hair. But it’s also because it wasn’t a question posed by earlier (male) scientists, according to Lasisi.

“They were like, ‘Oh yeah, hair, it’s sexy on women, it’s probably sexual selection.’ But there was no effort to look into it as a unique human trait because they were more interested in our large brains, bipedalism, and whatnot,” Lasisi says.

How Did Different Hair Types Come To Be?

Blond woman facing forsythia bush
iStock/lprogressman

Even the lack of categorization for hair types is telling. Contrary to what your shampoo bottle may say, there is no real classification system for different hair types. At least not yet.

“Most mammals have straight hair. Only human hair [in African and Melanesian populations] has this tightly coiled configuration. We tend to talk about hair as straight, wavy, curly, in some cases frizzy,” Lasisi says. “But it’s as if we were trying to do genetic studies on height saying, there are short people, medium people, and tall people, now find what genes are related to that.”

In other words, before she could even attempt to answer the question of which genes control the texture and color of hair, Lasisi had to figure out a system for defining those hair textures and colors. Lasisi set about creating a classification system that she eventually hopes to publish, which relies on microscopic analysis of curl radius and measuring precise amounts of melanin in the hair. She then tried to answer the first of many questions: Whether tightly coiled African hair evolved in response to the hot environment. While that research is still ongoing, she says the results may indicate something counterintuitive—the thicker the hair, the better insulator it is from heat.

What's the oldest human hair ever found?

Woman wearing African jewelry viewed from the back
iStock/FernandoPodolski

On the rare occasions when hair is preserved in the fossil record, it can be an incredible source of information about our ancestors’ health and behavior. In 2009, Lucinda Backwell and colleagues described the discovery of what appeared to be human hair in fossilized hyena poop (a.k.a. coprolites) from more than 200,000 years ago—the oldest evidence of human hair to date. Five years later, Backwell and others followed that study with an examination of 48 hairs from hyena coprolites that identified several mammalian species. The presence of all those types of hair mean the hyenas were scavenging from many different remains, including humans.

“In the case of the human hairs in the coprolite, they told us a lot, because there were no bones,” Backwell, an anthropologist with the University of Witwatersrand in South Africa and Instituto Superior des Estudios Sociales, CONICET in Argentina, tells Mental Floss by email. They revealed that humans shared the environment with big herbivores like impala, zebra, kudu, and warthogs in southern Africa 200,000 years ago. Unfortunately for scientists, all of the keratin in that hair sample had been replaced by calcium carbonate that didn’t include any DNA. “The first prize would be to extract DNA and identify whether the hair belonged to a modern or archaic human, or even someone like Homo naledi, with its primitive features and young age,” Backwell said. In addition to helping identify the precise species of hominin, DNA from a hair sample like this could go a long way in telling more about different species’ relationship to one another.

Backwell has also studied human hair found in a high-altitude cave site in Argentina, one of the best environments for preserving hair because it’s “cool, dry, dark, and with a neutral pH,” she says. Like the coprolite hairs in South Africa, dating and identifying hairs in Argentina will help Backwell and others understand the spread of humans across the world.

How Can Hair Shed Light on History?

Woman with brown wavy hair facing the ocean
iStock/lprogressman

When people are exposed to substances in the environment, their hair will retain some of the chemical signatures of those substances. Hair found in ice, in amber, and on mummies from arid regions around the world has allowed researchers to learn fascinating details about the inhabitants of particular regions.

In 2013, archaeologists at the University of Chile analyzed 56 mummy samples found in northern Chile. Using gas chromatography-mass spectrometry (a tool that identifies different substances in a sample—and also happens to be used for drug testing), they found that people had smoked nicotine-containing plants continuously from 100 BCE to 1450 CE. “Overall, these results suggest that consumption of nicotine was performed by members of the society at large, irrespective of their social and wealth status,” the researchers wrote in their study.

Another group of archaeologists collected hair samples from 40 mummies found in Peru, Chile, and Egypt to analyze pre-industrial mercury concentrations across the world, ranging in time from 5000 BCE to 1300 CE [PDF]. Their results, published in 2018, indicated much lower levels of mercury in the environment than in the industrial era. Researchers also discovered that each group’s diet determined the actual level of mercury exposure—the Chilean mummies had higher concentrations from their seafood-based diet, while the Egyptians, who ate land animals, had the lowest.

For now, the mystery of hair’s evolution remains partially unsolved. But the next time you’re at the salon, look in the mirror and remember: Hair is part of what makes us human.

9 Facial Reconstructions of Famous Historical Figures

A facial reconstruction of King Richard III unveiled by the Richard III Society in 2013
A facial reconstruction of King Richard III unveiled by the Richard III Society in 2013
Dan Kitwood/Getty Images

Why look at a painting of a historical figure when you can come face to face with one? Forensic facial reconstruction using scans of skeletal remains allows researchers to create 3D models of the face through a combination of science, history, and artistic interpretation. The results may be somewhat subjective, but they’re fascinating anyway. Here are nine facial reconstructions of famous people.

1. Richard III

In 2012, King Richard III’s skeleton was found below a parking lot in Leicester, England, where in 1485 he was hurriedly buried after dying in battle. A reconstruction (above) shows a young man, only 32 years old, with a gentle, approachable face. It’s a far cry from the child-murdering villain portrayed by Shakespeare and other writers. One thing they said does seem accurate, however: The skeleton had a curved spine from scoliosis, suggesting that Richard’s humpback may have been real.

2. Bach

J.S. Bach’s bust has sat on innumerable pianos for centuries, but he only posed for one portrait in his lifetime. So this reconstruction of his face—which was taken from a bronze cast of his skull—offers an interesting glimpse into the man beneath the 18th century wig. You get the same thick neck, underbite, and stern brow you see in the painting, but the reconstruction’s friendly, confused stare lacks the soul of the real man … and his music, for that matter.

3. Shakespeare

Apparently, no one knows anything about Shakespeare for sure—his hair color, his sexual orientation, how he spelled his name, whether he liked his wife, etc. Some people aren’t even sure whether he wrote his plays or not. So this rendering, taken from a death mask found in Germany, is bound to be controversial. But if it is Shakespeare, it’s pretty intriguing. It shows a man who suffered from cancer and had a sad, soulful face.

4. Dante

Maybe it’s because The Divine Comedy dealt with the ugliness of sin that Dante Alighieri is usually depicted as unattractive, with a pointy chin, buggy eyes, and enormous hooked nose. But a reconstruction done from measurements of the skull taken in 1921—the only time the remains have been out of the crypt—reveals a much more attractive Dante. The face has a rounder chin, pleasant eyes, and smaller nose than previously thought. It’s a face with character.

5. King Henri IV

The mummified head of France’s King Henri IV was lost after the French Revolution until a few years ago, when it showed up in a tax collector’s attic. In his day, Henri was beloved by everyone except the Catholic fundamentalists who murdered him in 1610. The hard-living king looks a bit old for his 56 years, but there’s a twinkle in his eyes. What the model cannot show, however, was how much the king stank—apparently he smelled of ”garlic, feet and armpits.”

6. Cleopatra’s Sister

Cleopatra hated her half-sister Arsinoe IV so much she had her dragged out of the temple of Artemis and murdered. In 2013, researchers said they had discovered what may be Arisone’s body, based on the shape of the tomb, carbon dating, and other factors. The resulting facial reconstruction shows a petite teenager of European and African blood. And yeah, maybe this is closer to what Arsinoe would look like if she were trapped in The Sims, but since Cleopatra’s remains are long gone, this may be the closest we get to knowing what she looked like.

7. King Tut

King Tutankhamun, whose famous sarcophagus has traveled far more than the “boy king” did in his 19-year lifetime, had buckteeth, a receding chin, and a slim nose, according to 3D renderings of his mummy. His weird skull shape is just within range of normal and was probably genetic—his father, Akhenaten, had a similarly shaped head. Tut’s body also had a broken leg, indicating he may have died from falling off a horse or chariot.

8. Copernicus

Nicolaus Copernicus, who challenged the belief that the sun revolved around the earth, died in 1543 at age 70. When his body was found in 2006 in a Polish church and confirmed by matching DNA to strands of his hair left in a book, the Polish police used their forensic laboratory to make this portrait. They made sure to include Copernicus’s broken nose and the scar above his left eye. Who knew that the Father of Astronomy looked so much like the actor James Cromwell?

9. Santa Claus

The remains of St. Nicholas, i.e. Santa Claus, have been in a church in Bari, Italy, since they were stolen from Turkey in 1087. This reproduction, taken from measurements of his skull, reveal that St. Nicholas had a small body—he was only 5’6”—and a huge, masculine head, with a square jaw and strong muscles in the neck. He also had a broken nose, like someone had beaten him up. This is consistent with accounts of St. Nicholas from the time: It turns out that Santa Claus had quite a temper.

A version of this list was first published in 2013.

Bombshell, Victoria’s Secret’s Bestselling Fragrance, Also Happens to Repel Mosquitoes

Dids, Pexels
Dids, Pexels

People love Bombshell, the best-selling fragrance at Victoria’s Secret, for its summery blend of fruity and floral notes. Not everyone is a huge fan, though: As Quartz reports, the perfume is surprisingly good at warding off mosquitoes. In fact, it’s almost as effective as DEET insect repellent, according to the results of a 2014 experiment by researchers at New Mexico State University.

Researchers took 10 products that are commercially available and tested their ability to repel two different species of mosquitoes: the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus), both of which are known to transmit diseases like dengue fever, chikungunya, and yellow fever. In doing so, volunteers subjected their own flesh to the test by placing their hands on either side of a Y-shaped tube containing the blood-sucking critters. One hand was covered in a synthetic rubber glove, while the other hand was sprayed with one of the products but otherwise left bare. Researchers recorded which tunnel the mosquitoes flew to, and how long they avoided the other end.

Three of the products contained DEET, while four products didn’t. In addition, there were two fragrances (including Bombshell) and one vitamin B1 skin patch. The DEET products were the most effective, but Bombshell proved to be nearly as good, keeping mosquitoes at bay for roughly two hours.

“There was some previous literature that said fruity, floral scents attracted mosquitoes, and to not wear those,” Stacy Rodriquez, one of the study’s authors, said in a statement. “It was interesting to see that the mosquitoes weren’t actually attracted to the person that was wearing the Victoria’s Secret perfume—they were repelled by it.”

This isn’t the first time a perfume has had an unintended effect on the natural world. It turns out that tigers are obsessed with Calvin Klein’s Obsession for Men cologne, partly because it contains a synthetic version of civetone, a pheromone that's secreted by glands located near a civet’s anus. This substance was once used to create musky fragrances, but nowadays the scent is mostly reproduced in a lab. Still, the fake stuff must be pretty convincing, because big cats go crazy when they catch a whiff of it.

[h/t Quartz]

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