October 10, 2013
In genetics, it’s not just the living who advance the field: DNA preserved in the brittle bones of our ancestors can provide significant insight into our genetic history. Such is the case with a new genetic history of Europe, traced by an international team of researchers and published today in Science. By creating a seamless genetic map from 7,500 to 3,500 years ago in one geographic region, scientists discovered that the genetic diversity of modern day Europe can’t be explained by a single migration, as previously thought, but by multiple migrations coming from a range of areas in modern day Europe.
To write the genetic history of Europe is to glance into the evolution of a Western culture and, often, to be greeted with more questions than answers: Why do 45 percent of Europeans share a distinct kind mitochondrial DNA (DNA passed down through the maternal line) known as haplogroup H? What causes one type of mitochondrial DNA to become dominant over another kind? Can changes in an archaeological record mirror changes in a genetic record?
The new genetic history might provide some answers to these questions. To attempt to piece together Europe’s vast genetic history, researchers from the Australian Centre for Ancient DNA (ACAD) at the University of Adelaide, the University of Mainz, the State Heritage Museum in Halle (Germany), and National Geographic Society’s Genographic Project extracted mitochondrial DNA from the teeth and bones of 396 prehistoric skeletons. These skeletons were found in a rather small and confined area within the German state of Saxony-Anhalt, an area which in previous studies had proved to hold a number of usable skeletal samples.
“We collected over 400 samples from skeletal individuals and extracted DNA. And for 396 of them, we got unambiguous results that could be confirmed,” says Dr. Wolfgang Haak of ACAD, a
lead author of the study. “DNA is not preserved in all individuals, so that was a fantastic success rate.”
The study included a wealth of data not seen before
–ten times as much mitochondrial DNA was examined as in previous studies, making it the largest examination of ancient DNA to date. Such a large amount of data allowed the researchers to create a “a gapless record…from the earliest farmers to the early Bronze Age,” says Haak in a press statement.
One of the ways researchers were able to piece together this gapless genetic record was by narrowing their skeletal samples to a single region. The region in Saxony-Anhalt is especially fruitful when it comes to ancient skeletal samples due to recent political history: after the Berlin Wall was torn down, part of former East Germany underwent a tremendous amount of infrastructural revitalization. In the process of digging new roads and motorways, a number of ancient skeletons were uncovered, boosting the archeological record so much that researchers have access to a sample of specimens ranging from 7,500 years ago to present-day. Moreover, by confining their search within distinct geographic parameters, the researchers were able to construct a real transect of what happened through time in a specific place, instead of a “patchy record of here and there,” as Haak describes the alternative.
What they found surprised them. In an earlier study, Haak and his colleagues used ancient DNA to show that lifestyles in Central Europe switched from hunting and gathering to farming around 5,500 BCE soon after a wave of migration from the Near East, evidenced
by a visible change in the genetic makeup when farming enters the archeological record. But the genetic diversity of modern Europe is too complex to be explained by this migration event alone.
The conundrum that left Haak and researchers puzzled–until now. By taking samples from specimens that create a complete timeline in Saxony-Anhalt, the researchers could pinpoint when changes within the mitochondrial DNA occurred. Confirming their past finding, they saw that while the DNA patterns changed with the influx of farming, they also changed thousands of years later.
By comparing the timing of these genetic changes with a timeline of archaeological finds in central Europe, and by looking up the cultural origins of new artifacts that pop up in the timeline when these genetic changes happened, researchers suggest that the genetic history of Europeans was not only affected by a migration of farmers from the Near East, but by subsequent migrations from cultures in to the west (what is now the Iberian Peninsula) and east (what is now Latvia, Lithuania, the Czech Republic and other modern Eastern European countries).
“With this genetic timeline, we can confirm that the first genetic change occurred between hunter-gatherers and farmers, and it’s surprisingly stable for about two thousand years, when farming is completely established,” Haak explains. “Then, towards the end of the Neolithic, we gain a bit of momentum and see a bunch of early hunter-gatherer lineages coming back. And then again, shortly after that, we see new impulses, coming both from the East and the West. There are suddenly these additionally elements that make-up most of the modern-day diversity. By the time that we reach the early Bronze Age, we have mostly everything in place that we see today.”
The authors’ hypotheses on where these waves of migrations came from relies on the idea that new cultural artifacts, if found in a specific region, must have been brought by travelers far away. But new tools and artifacts, by themselves, don’t automatically mean that migrations have happened to freshen the gene pool: as Haak notes, just because one uses an iPod does not make one distinctly American, or European, or anything else. Nonetheless it seems that, at least in ancient times, new tools and technologies might have gone hand in hand with genetic influxes as migrants brought old techniques to their new lands.
September 12, 2013
For the left-handed people of the world, life isn’t easy. Throughout much of history, massive stigmas attached to left-handedness meant they were singled out as everything from unclean to witches. In Medieval times, writing with your left-hand was a surefire way to be accused of being possessed by the devil; after all, the devil himself was thought to be a lefty. The world has gotten progressively more accepting of left-handed folk, but there are still some undeniable bummers associated with a left-handed proclivity: desks and spiral notebooks pose a constant battle, scissors are all but impossible to use and–according to some studies–life-expectancy might be lower than for right-handed people.
What makes humanity’s bias against lefties all the more unfair
is that left-handed people are born that way. In fact, scientists have speculated for years that a single gene could control a left-right preference in humans. Unfortunately, they just couldn’t pinpoint exactly where the gene might lie.
Now, in a paper published today in PLOS Genetics a group of researchers have identified a network of genes that relate to handedness in humans. What’s more, they’ve linked this preference to the development of asymmetry in the body and the brain.
In previous studies, the researchers observed that patients with dyslexia exhibited a correlation between the gene PCSK6 and handedness. Because every gene has two copies (known as alleles), every gene has two chances for mutation; what the researches found was that dyslexic patients with more variance in PCSK6–meaning that one or both of their PSCK6 alleles had mutated–were more likely to be right-handed.
The research team found this especially interesting, because they knew that PCSK6 was a gene directly associated with the development of left-right asymmetry in the body. They weren’t sure why this would present itself only in dyslexic patients, as dyslexia and handedness are not related. So the team expanded the study to include more than 2,600 people who don’t have dyslexia.
The study found that PCSK6 didn’t work alone in affecting handedness in the general population. Other genes, also responsible for creating left-right asymmetry in the body, were strongly associated with handedness. Like PCSK6, the effect that these genes have on handedness depends on how many mutations the alleles undergo. Each gene has the potential for mutation–the more mutations a person has in any one direction (toward right handedness or left handedness) the more likely they are to use that hand as their dominant hand, or so the researchers speculate.
The hypothesis is a logical response to a key question: If handedness is genetic and if
right-handedness is such a dominant trait, why hasn’t left-handedness been forced out of the genetic pool? In reality, the research suggests that handedness could be more subtle than simple “dominant” or “recessive” traits–a whole host of genes might play significant roles.
What’s especially exciting is that these genes all relate to the development of left-right asymmetry in the body and brain, creating a strong case for correlation between the development of this symmetry and the development of handedness. Disrupting any of these genes could lead to serious physical asymmetry, like situs inversus, a condition where the body’s organs are reversed (heart on the right side of the body, for example). In mice, the disruption of PCSK6 resulted in serious abnormal positioning of organs in their bodies.
If physical asymmetry is related to handedness, then people with situs inversus should favor one hand more often than what you’d find in the general population. Studies show that this isn’t the case–individuals with this condition mirror the general population’s split in handedness–leading the researchers to postulate that while these genes certainly influence handedness, there might be other mechanisms in the body that compensate for handedness in the event of major physiological asymmetries.
Other animals, such as polar bears or chimpanzees, also have handedness–chimpanzees have been known to prefer one hand to the other when using tools or looking for food, but the split within a population hangs around 50/50. Humans are the only species that show a truly distinct bias toward one hand or the other: a 90/10 right/left split throughout the population.
One predominant hypothesis for this bias relates to another distinct human trait: language ability. Language ability is split between the different hemispheres of the brain, much like handedness, which suggests that handedness became compartmentalized along with language ability, For most, the parts of the brain that govern language are are present in the left-side of the brain–these people tend to be
right-handed. The few that have language skills focused in the right side of the brain tend to be left-handed.
However, William Brandler, a PhD student at Oxford University and the paper’s lead author, isn’t convinced that this theory holds much stock, as correlations between language and handedness in research aren’t well established. Brandler is more interested in learning how the permutations and combinations of genetic mutations play into humans’ likelihood to be right-handed. “Through understanding the genetics of handedness, we might be able to understand how it evolved,” he says. “Once we have the full picture of all the genes involved, and how they interact with other genes, we might be able to understand how and why there is such a bias.”
And he’s confident that even if environmental factors (like the continued hatred of lefties by two-thirds of the world) place pressure on handedness, any
baseline bias still boils down to genetics. “People think it’s just an environmental thing, but you’ve got to think, why is there that initial bias in the first place, and why do you see that bias across all societies? Why aren’t there societies where you see a bias to the left?” Brandler asks. “There is a genetic component to handedness, hundreds of different genetic variants, and each one might push you one way or the other, and it’s the type of variance, along with the environment you’re in and the pressures acting on you, which affect your handedness.” But until a larger population can be tested–hundreds of thousands, by Brandler’s estimates–a full genetic map of what controls handedness and why our population isn’t evenly split between righties and lefties can’t be determined. “It’s going to take a bit of time before these materialize—but it will happen,” Brandler says. “There’s been a whole revolution in genetics such that, in a few years time, we’re really going to start to understand the genetic basis of complex traits.”
September 10, 2013
Rising gas prices and a dangerously low world panda population–what if someone told you that we soon could have one solution to both these problems? If it seems too good to be true, think again; scientists at Mississippi State University are conducting research on the feasibility of using pandas to help solve our biofuel woes, a step that could lead to a bump in conservation efforts and a drop in fuel expense. The secret to the solution? It’s all in the panda’s poop.
When it comes to biofuels, the market is dominated by one word: ethanol, a biofuel made from corn. Though ethanol is the most widely used biofuel, it isn’t necessarily touted as a perfect replacement for fossil fuels–in fact, the benefit of ethanol is been hotly debated since its creation.
The debate goes a little something like this: in order to fill the tank of an SUV with ethanol fuel, you need to use enough corn to feed a single person for an entire year. A 2012 paper published by the New England Complex Systems Institute cites ethanol as a reason for the increasing price of crops since 2005. And even environmental groups steer clear of ethanol, citing the massive amounts of fossil fuel needed to render corn a useable biofuel product and the propensity of companies to buy land in developing countries to grow the lucrative biofuel rather than food for local consumption.
Ashli Brown, a researcher at Mississippi State University, thinks she’s found the answer to this alternative fuel conundrum. By taking corn byproducts–the husks, the stems and cobs–ethanol could be created without dipping into the edible parts of corn, reducing the chance of a food shortage and price spike. The issue is that to break down these materials, which are extremely high in lignocellulose, or dry plant matter, a special pretreatment process is required. The process is extremely costly and not very time-efficient, using high temperatures, high pressures and acid to break down the dry plant matter before it can become ethanol. To circumvent this problem, Brown and other researchers have been looking for a natural solution–bacteria, which could help with the breakdown of the lignocellulose material.
Biofuel companies have been seeking a natural method to break down plant material for a while; so far, termites have been a favorite for chewing through the woody material. But it turns out there might be a better–and cuter–animal that can help produce biofuel
. The intestines of pandas are remarkably short, a physical attribute which means their intestines have come to contain bacteria with unusually potent enzymes for breaking down their woody diet of bamboo in a short amount of time.
“The time from eating to defecation is comparatively short in the panda, so their microbes have to be very efficient to get nutritional value out of the bamboo,” Brown, the researcher heading the work, said. “And efficiency is key when it comes to biofuel production—that’s why we focused on the microbes in the giant panda.”
The study began more than two years ago, when Brown and a team of researchers began looking at panda feces. In 2011, they identified these super-digesting microbes are present in panda feces, but they had yet to specify the type and amount of microbes present until now. Using the poop from two giant pandas–Ya Ya and Le Le in the Memphis Zoo–Brown and her team performed DNA sequencing on microbes in their samples, identifying more than 40 microbes in the panda feces that could be useful to the breakdown and creation of biofuels.
To grow these microbes on an industrial scale
, Brown believes that scientists could put the genes that produce those enzymes into yeasts--these yeasts could then be mass-produced and harvested for biofuel production. The process would go something like this: Large pits of corn husks, corn cobs, wood chips, and other forms of discarded fibrous material are covered with the genetically altered yeasts. As the microbes digest woody substances, they quickly turn it into sugar, which would then be allowed to ferment. Over time and after filtering out solids and any excess water, you would have ethanol, distilled from woody waste products.
Pandas aren’t the only animal that subsists on a grassy diet, but their physiology makes them a unique candidate for breaking down plant byproducts in a hyper-efficient way. Pandas have the same digestive track as any other bear; unlike cows or other herbivores, pandas don’t have an extra stomach where hard lignocellulostic material is pretreated before being digested. Instead, they have the intestinal system of a carnivore, and yet manage to extract enough nutrients from their herbaceous diet to survive.
“Because their retention time is very short—they’re constantly eating and they’re constantly pooping—in order to get the material for nutrition, they have to be really quick at breaking it down and extracting the sugars,” Brown explained. “Many microbes produce celluloses that breakdown lignocellulostic biomass, but it’s about how efficiently or how effectively they do it.” When it comes to a panda, Brown notes, their microbes are some of the most efficient scientists have seen at breaking down the woody material of a plant.
And Brown thinks that using pandas for their poop could lead to more than a greener economy: it could also lead to increased conservation for the animals, who have seen their numbers in the wild drop to a dangerous 1,600 (though there has been recent luck with breeding pandas in captivity, like the new baby panda at the National Zoo). “These studies also help us learn more about this endangered animal’s digestive system and the microbes that live in it, which is important because most of the diseases pandas get affect their guts,” said Brown.
Brown notes that if the panda becomes valuable to the market for more reasons than its incredibly adorable demeanor, it might spark greater steps toward conservation–a move that could be mutually beneficial to pandas and humans alike.”It’s amazing that here we have an endangered species that’s almost gone from the planet, yet there’s still so much we have yet to learn from it. That underscores the importance of saving endangered and threatened animals,” she said. “It makes us think—perhaps these endangered animals have beneficial outputs that we haven’t even thought about.”
August 28, 2013
If the phenomena of Star Trek, Area 51, Ancient Aliens, or War of the Worlds can be taken as anthropological clues, humanity is consumed with curiosity about the possibility of life beyond Earth. Do any of the 4,437 newly discovered extrasolar planets contain traces of life? What would these life forms look like? How would they function? If they came to Earth, would we share ET-esque embraces or would the visit be more a Battle Los Angeles style throw down?
Life outside of Earth has spawned endless interest, but less public interest seems to be given to how life on Earth began 3 to 4 billion years ago. But the two topics, it turns out, might be more connected than one would believe–in fact, it’s possible that life on Earth really began outside of Earth, on Mars.
At this year’s Goldschmidt conference in Florence, Steve Benner, a molecular biophysicist and biochemist at the Foundation for Applied Molecular Evolution will present this idea to an audience of geologists. He’s well aware that half the room will be adamantly against his idea. “People will probably throw things,” he laughs, hinting at a consciousness of how out-of-this-world his ideas sound. But there’s scientific basis for his assertion (PDF), a logical reason for why life maybe truly did begin on Mars.
Science holds a number of paradoxes: If there are an infinite number of stars in the sky, why is the night sky dark? How can light act as both a particle and a wave? If the French eat so much cheese and butter, why is the incidence of coronary disease in their country so low? The origins of life are no different; they, too, are dictated by two paradoxes: the tar paradox, and the water paradox. Both, according to Benner, make it difficult to explain the creation of life on Earth. But both, he also notes, can be solved by placing the creation of life on Mars.
The first, the tar paradox, is simple enough to understand. “If you put energy into organic material it turns to asphalt, not to life,” Benner explains. Without access to Darwinian evolution–that is, without organic molecules having the opportunity to reproduce and create offspring who themselves, mutations and all, are reproducible–organic matter that is bathed in energy (from sunlight or from geothermal heat) will turn into tar. Early Earth was full of organic materials–chains of carbon, hydrogen and nitrogen that are believed to be the building blocks of life. Given the tar paradox, these organic materials should have devolved into asphalt. “The question is, how is it possible that the organic materials on early Earth managed to leap from their asphaltic fate to something that had access to Darwinian evolution? Because once that happens–presumably–you’re off to the races, and then you can manage whatever environment you want,” Benner explains.
The second paradox is the so-called water paradox. The water paradox states that even though life needs water, if organic material could escape its asphaltic fate and move toward Darwinian evolution, you can’t assemble the necessary building blocks in a flood of water. The building blocks of life start with genetic polymers–the well-known player DNA and its less-famous but still very smart friend RNA. Experts agree that RNA was likely the first genetic polymer, partly because in the modern world, RNA plays such an important role in the manufacturing other organic compounds. “RNA is the key to the ribosome, which is what makes proteins. There’s almost no question that RNA, which is a molecule involved in catalysis, arose before proteins arose,” Benner explains. The difficulty is that for RNA to assemble into long strands–which is needed for genetics–you can’t have the assembly taking place in water. “Most people think that water is essential for life. Very few people understand how corrosive water is,” Benner says. For RNA, water is extremely corrosive–bonds cannot be made within water, preventing long-strands from forming.
However, Benner says that these paradoxes can be resolved with the help of two very important groups of minerals
. The first are borate minerals. Borate minerals–which contain the element boron–prevent life’s building blocks from devolving into tar if incorporated into organic compounds. Boron, as an element, is seeking electrons to make itself stable. It finds these in oxygen, and together the oxygen and boron form the mineral borate. But if the oxygen boron finds is already bonded to carbohydrates, the carbohydrates linked with boron form a complex organic molecule dotted with borate that’s less resistant to decomposition.
The second group of minerals that come into play
involve those that contain molybdate, a compound that consists of molybdenum and oxygen. Molybdenum, more famous for its conspiratorial relation to the Douglas Adams classic A Hitchhiker’s Guide to the Galaxy than for its other properties, is crucial, because it takes the carbohydrates that borate stabilized, bonds to them and catalyzes a reaction which rearranges them into ribose: the R in RNA.
Which brings us–however circuitously–back to Mars. Both borate and molybdate are scarce and would have been especially scarce on early Earth. The molybdenum in molybdate is
highly oxidized, meaning that it needs electrons from oxygen or other readily available negatively charged ions to achieve stability. But early Earth was too oxygen-scarce to have readily created molybdate. Plus, returning to the water paradox, early Earth was quite literally a water world–with land making up only two to three percent of its surface. Borates are soluble in water–if early Earth was a flooded planet, as scientists believe, it would have been difficult for an already scarce element now diluted in a huge ocean to find ephemeral organic molecules to bond with. Moreover, Earth’s status as a water-logged planet makes it difficult for RNA to form, because that process can’t easily happen in water on its own.
These concepts become less of an issue on Mars, however. Though water was certainly present on Mars 3 to 4 billion years ago, it was never as abundant as it was on Earth, creating the possibility that Martian deserts–locations where borate and molybdate could concentrate–could have fostered the formation of long strands of RNA. Moreover, 4 billion years ago, Mars’ atmosphere contained much more oxygen than Earth’s. Further, recent analysis of a Martian meteorite confirms that boron was once present on Mars.
And, Benner believes, molybdate was there too. “It’s only when molybdenum becomes highly oxidized that it is able to influence how early life formed,”Benner explains. “Molybdate couldn’t have been available on Earth at the time life first began, because three billion years ago the surface of the Earth had very little oxygen, but Mars did.”
Benner believes that these factors imply that life originated on Mars, our closest neighbor in space equipped with all the right ingredients. But life wasn’t sustained there. “Of course Mars dried out. The process of drying was very important for life originating, but not sustaining,” Benner explains. Instead, a meteor would have to have hit Mars, projecting materials into space–and eventually those materials, including some building blocks of life, might have made it to Earth.
Would the sudden change in environment have been too harsh for the fledgling building blocks to survive
? Benner doesn’t think so. “Let’s say life starts on Mars, and becomes very happy in the Martian environment,” Benner explains. “A meteor comes to hit Mars, and the impact ejects rocks on which your predecessor is sitting. Then you land on Earth, and you discover that there is lots of water that you were treating as a scarce element. Will it find the environment adequate? It certainly appreciated the existence of enough water that it didn’t have to worry.”
So, sorry Lil Wayne, looks like it might be time to relinquish your claim to the fourth rock from the Sun. As Brenner notes, “The evidence seems to be building that we are actually all Martians.”
August 22, 2013
Modern archeologists, excavating ancient Egyptian tombs, have often found something unexpected amongst the tombs’ artifacts: pots of honey, thousands of years old, and yet still preserved. Through millennia, the archeologists discover, the food remains unspoiled, an unmistakable testament to the eternal shelf-life of honey.
There are a few other examples of foods that keep–indefinitely–in their raw state: salt, sugar, dried rice are a few. But there’s something about honey; it can remain preserved in a completely edible form, and while you wouldn’t want to chow down on raw rice or straight salt, one could ostensibly dip into a thousand year old jar of honey and enjoy it, without preparation, as if it were a day old. Moreover, honey’s longevity lends it other properties–mainly medicinal–that other resilient foods don’t have. Which raises the question–what exactly makes honey such a special food?
The answer is as complex as honey’s flavor–you don’t get a
food source with no expiration date without a whole slew of factors working in perfect harmony.
The first comes from the chemical make-up of honey itself. Honey is, first and foremost, a sugar. Sugars are
hygroscopic, a term that means they contain very little water in their natural state but can readily suck in moisture if left unsealed. As Amina Harris, executive director of the Honey and Pollination Center at the Robert Mondavi Institute at Univeristy of California, Davis explains, “Honey in its natural form is very low moisture. Very few bacteria or microorganisms can survive in an environment like that, they just die. They’re smothered by it, essentially.” What Harris points out represents an important feature of honey’s longevity: for honey to spoil, there needs to be something inside of it that can spoil. With such an inhospitable environment, organisms can’t survive long enough within the jar of honey to have the chance to spoil.
Honey is also naturally extremely acidic. “It has a pH that falls between 3 and 4.5, approximately, and that acid will kill off almost anything that wants to grow there,” Harris explains. So bacteria and spoil-ready organisms must look elsewhere for a home–the life expectancy inside of honey is just too low.
But honey isn’t the only hygroscopic food source out there. Molasses, for example, which comes from the byproduct of cane sugar, is extremely hygroscopic, and is acidic, though less so than honey (molasses has a pH of around 5.5). And yet–although
it may take a long time, as the sugar cane product has a longer shelf-life than fresh produce, eventually molasses will spoil.
So why does one sugar solution spoil, while another lasts indefinitely? Enter bees.
“Bees are magical,” Harris jokes. But there is certainly a special alchemy that goes into honey. Nectar, the first material collected by bees to make honey, is naturally very high in water–anywhere from 60-80 percent, by Harris’ estimate. But through the process of making honey, the bees play a large part in removing much of this moisture by flapping their wings to literally dry out the nectar. On top of behavior, the chemical makeup of a bees stomach also plays a large part in honey’s resilience. Bees have an enzyme in their stomachs called glucose oxidase (PDF). When the bees regurgitate the nectar from their mouths into the combs to make honey, this enzyme mixes with the nectar, breaking it down into two by-products: gluconic acid and hydrogen peroxide. “Then,” Harris explains, “hydrogen peroxide is the next thing that goes into work against all these other bad things that could possibly grow.”
For this reason, honey has been used for centuries as a medicinal remedy. Because it’s so thick, rejects any kind of growth and contains hydrogen peroxide, it creates the perfect barrier against infection for wounds. The earliest recorded use of honey for medicinal purposes comes from Sumerian clay tablets, which state that honey was used in 30 percent of prescriptions. The ancient Egyptians used medicinal honey regularly, making ointments to treat skin and eye diseases. “Honey was used to cover a wound or a burn or a slash, or something like that, because nothing could grow on it – so it was a natural bandage,” Harris explains.
What’s more, when honey isn’t sealed in a jar, it sucks in moisture. “While it’s drawing water out of the wound, which is how it might get infected, it’s letting off this very minute amount of hydrogen peroxide. The amount of hydrogen peroxide comes off of honey is exactly what we need–it’s so small and so minute that it actually promotes healing.” And honey for healing open gashes is no longer just folk medicine–in the past decade, Derma Sciences, a medical device company, has been marketing and selling MEDIHONEY, bandages covered in honey used in hospitals around the world.
If you buy your honey from the supermarket, that little plastic bottle of golden nectar has been heated, strained and processed so that it contains zero particulates, meaning that there’s nothing in the liquid for molecules to crystallize on, and your supermarket honey will look the same for almost forever. If you buy your honey from a small-scale vendor, however, certain particulates might remain, from pollen to enzymes. With these particulates, the honey might crystallize, but don’t worry–if it’s sealed, it’s not spoiled and won’t be for quite some time.
A jar of honey’s seal, it turns out, is the final factor that’s key to honey’s long shelf life, as exemplified by the storied millennia-old Egyptian specimens. While honey is certainly a super-food, it isn’t supernatural–if you leave it out, unsealed in a humid environment, it will spoil. As Harris explains, ” As long as the lid stays on it and no water is added to it, honey will not go bad. As soon as you add water to it, it may go bad. Or if you open the lid, it may get more water in it and it may go bad.”
So if you’re interested in keeping honey for hundreds of years,
do what the bees do and keep it sealed–a hard thing to do with this delicious treat!