There are countless crime scenes every day. It's up to experts to turn back time and figure out what happened using evidence left behind, such as blood.

Until now, blood DNA tests could determine someone's ethnicity and sex, but they couldn't determine age. The tests also took several days to yield results. But now things are changing.

A new ACS publications study could help crime scene experts better analyze blood evidence. The study researchers developed a new blood test that can be used at a crime scene to determine someone's age range from blood left at the scene. The test works with blood samples collected within two days of being deposited. 

The test measures the levels of an enzyme, called alkaline phosphatase, in blood. The levels of this enzyme change in the body between childhood and adulthood.

Researchers completed the study by synthesizing human blood. They then calculated the ages of the people it could have come from. When trialing the blood test, the team was able to correctly identify ages at an almost 100% success rate.

The blood test is still in early development, which means, of course, that there are a couple of problems that still require further testing. For example, scientists are still unsure about how much human blood they need for the test to be accurate. Also, since many crime scenes are discovered more than 2 days after the blood is deposited there, it may be too diluted to use in tests if the crime scene is too old.

MORE: A surprising number of animals can reproduce without sex

UP NEXT: I asked more than 20 healthcare leaders for their best career advice — here's the one that stuck with me

Join the conversation about this story »

NOW WATCH: This is how big an asteroid would need to be to wipe out New York City

Unsurprisingly, a majority of research on what traits men find attractive in women has focused on various aspects of women's bodies. Because we know it's not all about looks, here are 7 qualities men find attractive in women from studies that didn't focus solely on appearances. 

Follow TI:On Facebook

Join the conversation about this story »

When most people think of sharks, a particular image comes to mind: a dorsal fin sticking out of the water, or for some people, just the very fictional great white shark from "Jaws."

And while the average person really has no reason to worry about sharks in the first place, depictions of sharks in popular media tend to focus on just a few species: white sharks, bull sharks, and tiger sharks, especially.

But there are all kinds of different sharks out there — more than 500 species, in a great variety of shapes and sizes. They've been around since before the dinosaurs, and the vast majority of species have never even accidentally nibbled on a human swimmer. 

So check out some of the weirdest, most fascinating creatures in the ocean.

The rarely seen megamouth shark can live 100 years and resides thousands of feet below the surface — but it rises up at night to snack on tiny plankton.

Source: Reuters, Discovery

Though they are almost never seen and don't get to be much larger than 6 feet, the frilled shark certainly looks like it could be responsible for tales of ancient sea monsters — check out those rows of teeth!

This teeny tiny pocket shark, discovered last year, is just the second one ever found.

Source: Business Insider

Just this past June, a 2-year-old boy was playing near the water at a Disney World resort when an alligator attacked and killed him. A black bear attacked a woman running the marathon in New Mexico just a few days later. In Colorado, a mother had to fight off a mountain lion to save her 5-year-old son that was attacked in their own backyard.

Even when the headlines about wildlife don’t involve attacks — a bear is spotted swimming in a backyard pool, for example, or a great white shark is tagged off the coast of Cape Cod — we are still vividly reminded that America is not only our home, but also the home to some dangerous, wild predators as well. And sometimes these creatures are closer than we think.

But how dangerous are these animals really? How afraid of them should we be? Well, it turns out, we shouldn’t be too afraid since the animals we fear most might not actually be the most deadly. For example, dogs, deer, and cows kill more Americans every year than bears, sharks, or alligators.

So from wolves to spiders, here is a look at 10 creatures that most normal Americans fear, where they live, and just how dangerous they really are.

SEE ALSO: Great whites are back in Cape Cod — here's what you need to know

DON'T MISS: Lionfish have invaded the Mediterranean — here's why scientists are worried

Bears

Odds are if you see a bear, it will be a black bear, as they are the most common in the US. There are at least 600,000 black bears in North America and about half of those are found in the US. As opportunistic eaters, they have also developed a taste for human food and garbage, which has made them more brazen and more dangerous.

Grizzly bears are bigger, weighing upwards of 700 pounds, and they are very fast runners (some have been clocked running at 30 miles per hour, according to National Geographic.) There are an estimated 1,800 grizzly bears remaining in the lower 48 states.

Your chances of being injured by a bear are approximately 1 in 2.1 million, according to the National Park Service. Between 1900 and 2009, around 63 people were killed in 59 incidents involving black bears, according to a report in Wildlife Management, which is a relatively low number. Grizzlies are more threatening, with the average encounter being 21 times more dangerous than a black bear encounter, reports National Geographic. Encounters with mothers and their cubs create the most dangerous situations.

So, if you are in bear country, remember to try not to attract bears with food and perfume. Carry bear spray if you are hiking and travel in groups. Stand your ground, don’t run, and make loud noises if you run into one to try to scare them away.

Sharks

For those of us that have seen the movie Jaws, sharks can be terrifying. Of the many different kinds of sharks swimming in our oceans, some of the ones most often involved in attacks on humans are great whites, bull sharks, and tiger sharks. While great whites might be the biggest, bull sharks are the most aggressive. They also hunt closer to shore and in shallower waters.

It is important to note though, that no shark typically hunts humans, according to NOAA, and when they do, it is usually a case of mistaken identity— we humans are mistaken for their normal prey, such as seals. Typically, the US sees only about 30-40 shark attacks a year, reports USA Today, and, on average, maybe only one of those is deadly.

If you are planning on swimming in the ocean, try to swim in groups, don’t swim with any kind of open cut, take off any shiny jewelry, and try not to splash too much. It is also best to avoid swimming at dawn and dusk, when sharks usually prey.

Mountain lions and Florida panthers

Mountain lions go by many names, including pumas, cougars, or catamounts. They are North America’s largest wildcat and they can be fierce predators, with powerful limbs, sharp claws, and the ability to leap as high as 15 feet and as far as 40 feet, according to Defenders of Wildlife.

The big cats roam from California to Texas, and some — like P-22, the cougar accused of killing a koala at the LA Zoo — live near cities. There are an estimated 30,000 of these animals in the US. The Florida panthers, a subspecies of the mountain lion, are less commonly seen because they are critically endangered, with only 100 to 180 left in the wild.

The chances of a person being attacked are small, though, because the cats are shy and usually avoid humans. When they do attack, children or solitary adults are usually the victims. According to National Geographic, there are on average only four mountain lion attacks and one fatality each year in all of the U.S. and Canada.

At a certain time of the month, men can smell that women are more attractive.

That time is the 12 to 24-hour window when a woman is ovulating, scientists have found.

Multiple studies have concluded that men find women more attractive during ovulation.

This is the one time a month that the ovaries release an egg ready for fertilization.

So it's the time when women are most fertile, and men seem to be biologically programmed to pick up on that.

It's rather entertaining how many times different scientists have subjected men (who are usually undergrads getting a small chunk of change) to bizarre smelling experiments.

Scientists have had men smell women's T-shirts and underarm patches, and men consistently rate the women who are ovulating as more attractive. It's unclear, however, how powerful this effect might be; other factors that shape our perception of attraction are likely far stronger in the real world.

Smelling samples from ovulating women also encouraged men to make riskier decisions in one study.

Ovulation typically happens around the 14th day of a 28-day menstrual cycle. Many types of birth control block ovulation from happening in order to prevent pregnancy, so women on the pill, for example, may not benefit from this attractiveness peak.

These days, there are apps like Glow that can help women determine when they're ovulating.

Pro-tip: Maybe if you try that Smell Dating service, ladies, you should make sure you're ovulating on the days when you wear the T-shirt.

MORE: Here's how your Fourth of July fireworks work

UP NEXT: Here's how you can finally get over regret

Join the conversation about this story »

NOW WATCH: 7 qualities in women that men find attractive, according to science

It happens all the time. A new album comes out, you listen to it, and before you know it, you have a new favorite song. So you play it again. And again. And again. It’s on loop for days: in the car, at home. Maybe you even hum it to yourself while you work.

But then, all of the sudden, it changes. You get sick of that same song you once loved.

So why does this happen? We asked Elizabeth Hellmuth Margulis, author of “On Repeat: How Music Plays the Mind” and director of the Music Cognition Lab at the University of Arkansas, for the answer.

The brain listening to music

Every time we listen to music, our brain responds.

Researchers have shown, using fMRI brain scans, that when listening to music, not only does the auditory cortex (that part of the brain responsible for processing sounds) light up, but other parts do as well, including brain regions involved in movement, planning, attention and memory.

This means when we listen to music, we aren’t just processing sound. We are involved. We are focusing and learning. Sometimes we even “feel” the song.

“We have a lot of measures demonstrating that people are experiencing this participatory sense when they are listening to music,” Margulis told Business Insider. The involvement of the motor parts of the brain is also why we sometimes feel the urge to tap our feet along to the beat, or rock out with an air guitar.

Falling in love with the song

When we like a song, we are more likely to listen to it again, and by doing so, we are starting the cycle of “falling in love” with it.  A study in PLOS ONE found that more of the brain’s emotional circuitry tends to be active when we listen to music we are familiar with. We are more likely to experience an emotional reaction.

The second time you listen, your brain also has an easier time processing it. In other words, Margulis said, “your brain can handle [the song] better because it knows what to predict about it [and] your brain understands it.” Each additional listen only amplifies this effect.

In fact, research by Swedish psychologist Alf Gabrielsson found that when people had really pleasurable experiences with music, they sometimes reported “losing themselves” to the melody for its duration. “Repetition is really helping that happen,” Margulis explained. “It is helping you embody the tune.”

That is, until all this repetition gets old.

Why we get sick of it

At some point, a contravening force kicks in, Margulis said, and makes us want to start looking for something new to explore and learn about. “If we keep revisiting the same place again and again and again, we never learn,” she said. “So there is a competing drive to explore and find new things.” Your brain is no longer surprised by what it hears and a different instinct drives you away from it so you can find a new song to discover and love.  

And then, it begins all over again.

SEE ALSO: Dogs are a wonderful source of comfort after a tragedy — here's why

Join the conversation about this story »

NOW WATCH: Here's what popular dog breeds looked like before and after 100 years of breeding

Goats might be more like dogs than we thought.

A new study, published in Biology Letters, suggests that goats, like dogs, have the capacity to communicate their intentions or desires to people.

Scientists gave the animals a simple task: take the lid off a box to receive a food reward while a human sat nearby. Over time, the researchers made it increasingly difficult to open the box, until the task became “impossible.”

At that point the goats, when they were faced with this unsolvable problem, looked repeatedly between the reward and the human, and even stared at the human “imploringly” to try to indicate that they needed help to get to the treat.

This behavior had been previously noted in dogs — animals with which we are known to feel a special bond — but this was new when it came to goats.

“Goats gaze at humans in the same way as dogs do when asking for a treat that is out of reach,” said Dr. Christian Nawroth, study author, in a press release. “Our results provide strong evidence for complex communication directed at humans in a species that was domesticated primarily for agricultural production, and show similarities with animals bred to become pets or working animals, such as dogs and horses.”

There are about a billion goats worldwide, reports The Telegraph, and these animals are believed to be the first livestock species to be domesticated, roughly 10,000 years ago. Unlike dogs though, goats were domesticated for their meat and milk, not to provide a social need (as dogs were to help us hunt).

Perhaps, the reason for this cross-species sociability has something to do with goats’ natural desire to explore, Dr. Jenna Kiddie, senior lecturer in animal behavior and welfare at Anglia Ruskin University, told The Guardian. Sheep, in comparison, are more skittish and tend to cluster in packs, so they don’t have much need to gaze up at us.

The study authors hope that their research will lead to a better understanding of just how skilled livestock are in their ability to solve problems and interact with humans based on their cognitive abilities.

SEE ALSO: 9 special abilities that show how smart dogs really are

DON'T MISS: Dogs are a great source of comfort after a tragedy — here's why

Join the conversation about this story »

NOW WATCH: 4 ways aliens could be contacting Earth without us knowing

The slingjaw wrasse, Epibulus insidiator, is a species of wrasse with an astounding jaw. Its mouth can extend over half the length of the fish's body. The fish can protrude its jaws longer than any other on the planet. Peter Wainwright of UC Davis recorded this video of the wrasse feeding in slow motion.

Footage courtesy of the Wainwright Lab and the NOAA Photo Library.

Follow TI:On Facebook

MORE: There could be a super-simple way to lose weight that doesn't involve diet or exercise

UP NEXT: Here's why some beaches have crystal-clear water and others are murky and gray

Join the conversation about this story »

For thousands of years, humans have searched for ways to extend life, perhaps to become immortal.

And while immortality seems to be as distant a goal as it ever has been, scientists have made significant progress in terms of extending life. The average lifespan for women in developed countries grew from under 50 to around 80 in the past 150 years or so, for example. But much of that difference comes from reducing infant mortality.

Defeating the diseases that affect us at the end of life — cancer, heart disease, diabetes, and others — has proven a harder venture.

One of the only life-extension strategies that we believe might actually work is extreme caloric restriction, which presents a whole set of practical challenges and potential health concerns. But researchers have been investigating a diet that requires just five days of fasting a month (potentially doing this every few months) to achieve the same cancer and disease fighting benefits. And this diet, the fasting-mimicking diet (FMD), might actually be able to transform health and slow the effects of aging.

Researchers think that perhaps the reason this diet works is that it lowers levels of a specific growth hormone, insulin-like growth factor-1 (IGF-1).

Scientists have studied people who naturally have low levels of this growth hormone (who also have a form of dwarfism, not due to the low levels of this hormone) and have found that they have shockingly low rates of cancer and diabetes, even if they are overweight or obese. The idea behind the FMD is to lower levels of this hormone in otherwise healthy people.

Lowering the same growth hormone in mice created the longest-lived lab mice in the world. And other more extensive studies in mice related to this same diet that may lower levels of this hormone showed changes that led to improved cognitive performance, a stronger immune system, and lower cancer risks. There were no negative side effects.

Although severalinitial studies of the FMD, including at least onein humans, have been promising and have lowered IGF-1 levels, more research will be needed to show that it's definitively safe and that modifying hormone levels is truly the cause of these potential health benefits. Still, it's fascinating to see how these tiny tweaks of small factors like hormone levels may have a huge impact.

SEE ALSO: 6 habits the longest-living people have in common

DON'T MISS: This science-backed online calculator will tell you your 'fitness age'

Join the conversation about this story »

NOW WATCH: This incredible bionic suit makes you feel like a 75-year-old

It's impossible to gaze at a magnificent underwater creature, like a dolphin or a trout, without pondering how it feels—to swim so fast, to dive so deep, to feel so comfortable in such as strange environment.

But have you ever wondered, as they go about their watery lives, what they're smelling?

Because all vertebrates come from the sea, smelling actually evolved there, too, says Dr. Keith Tierney, a fish olfaction expert at the University of Alberta. (Indeed, he points out, all olfaction arguably occurs underwater, as it requires the mucus in your nose.)

But ever since the first proto-mammal crawled onto the shore, our smellvolution has diverged, leaving underwater creatures with adaptations that seem curious, and occasionally mysterious, to us landlubbers.

Here's how some of our aquatic friends sniff around, and what they find when they do.

MORE: 8 of the world's coolest telescopes that are changing the way that we look at the universe

UP NEXT: Coney Island beaches were closed after sharks were spotted nearby

Fish

If you look closely at your goldfish's face, you might notice two tiny holes in his snout, not unlike the nostrils in your own.

Instead of heading down the throat like ours, though, these pinpricks, called "nares," lead into a small chamber padded with olfactory receptors. When water flows into these nares, it brings all the scents of the underwater world along with it.

While your average fish doesn't have too many different receptors (about 100, compared to a mouse's 1300), each of these receptors can detect many unique odors. As a result, Tierney says, fish can really read the room—not only figuring out who is predator and who is prey, but noting when other fish are stressed or ready to mate, and using scent cues to find their way back home.

They can also recognize all the new, smelly stuff we've been pumping into waterways. "Sometimes fish will avoid toxic chemicals," says Tierney, "but sometimes they appear to be attracted to them." The nose doesn't always know.

Crustaceans

When a lobster in a tank waves his appendages in your direction, he's not beckoning you over — he's probably trying to sniff you out.

Rather than bringing odors all the way into their faces, crustaceans have external organs called antennules — moustache-looking mini-antennae draped with fine hairs.

To smell, lobsters and crabs use these antennule like chemosensitive whips, grabbing smell samples during the downward snap and investigating them during the slower upstroke, explains marine biologist Dr. Mimi Koehl in a 2010 paper. In other words, Koehl writes, "each antennule flick is a 'sniff.'"

Once they've figured out what they're smelling, crustaceans can do a lot with the info: choose a mate, navigate in the dark, and establishurine-based dominance hierarchies. Smelling is so important, lobsters walk far more slowly when they're doing it, like deliberate detectives on the odor beat.

Whales, dolphins, and manatees

For a long time, scientists thought whales couldn't smell at all. The Inupiat, though, knew differently. Twice each year, as they hunted bowheads off the coast of Alaska, they were careful not to light fires on the ice and to build latrines upwind, for fear the smell of smoke or sewage would drive the whales away.

In 2008, anatomist Dr. Hans Thewissen tagged along on a bowhead hunt and came back with four whole whale brains.

Dissection revealed a distinct olfactory bulb, connected to the nostrils by a nerve several feet long, and DNA analysis showed plenty of genes that code for smell sensors. While bowheads still have no way of smelling underwater—they would choke—these structures indicates that when they come up for air, they get a whiff of the world.

This goes for manatees as well, although no behavioral studies have been conducted to see how they react to smells, says Nicola Erdsack of the Mote Marine Laboratory Manatee Research Program.

Meanwhile, most toothed whales, including dolphins, lack this olfactory structure entirely, suggesting that they're smell-blind in and out of the water. This is probably good, as whale breath smells,in the words of one observer, like "an unholy mingling of fart and fishiness."

Traveling can be an eye-opening experience for chimpanzees, forcing them to become more innovative. 

According to a study published Tuesday in the journal eLife, well-traveled chimpanzees are more inventive when it comes to devising tools to get access to food. 

This is believed to be because travel creates a need for more high-energy food, which in turn forces chimpanzees to improvise new ways to collect it.

The scientists arrived at these findings by analyzing 7 years of field experiments where 52 chimpanzees had to try to get honey from a hole in a wooden log. The limited amount of honey in the hole made it necessary for chimpanzees to use a tool, like a folded leaf or a stick, to get it out. The primates that only used their fingers to get to the honey didn't have much success.

The researchers found that the primates that interacted with the log and used tools to get to the honey were generally those that had travelled more than average in the previous weeks and those that had eaten fewer ripe fruits.  Those that were better-fed and less well-travelled didn't seem as motivated to get to the honey.  

In other words, the well-traveled primates had a more genuine and immediate need to replenish their energy, so they improvised tools to get to the delicious honey. 

UP NEXT: Here's what a serving size of each of your favorite foods looks like

MORE: Gypsy moth caterpillars have decimated large portions of New England forests this summer

Join the conversation about this story »

NOW WATCH: A spacecraft is about to explore Jupiter like never before — here’s what NASA fears the most

Bats can be found around the world, from Texas to Thailand. They make up a quarter of the world's known mammals. There are approximately 1,100 species of bats.

Bats around the world are threatened by increasing habitat loss and in North America, they are threatened by white nose syndrome. This is a fungal disease that deteriorates bats' wing membranes and damages their muzzles, ears, and skin. White nose syndrome also awakens bats out of torpor (their form of winter hibernation) before they are ready. White nose syndrome now affects bats in at least 29 states and 5 Canadian provinces. 

While a lot of people see bats as "scary" or "creepy," they play a vital role in their ecosystems. Bats help pollinate plants when they travel, they disperse seeds throughout forests, and their droppings even act as a fertilizer. Some even eat bugs and mosquitoes. 

Below is a list of 5 of the most unique bat species. (Warning: you might actually like bats after reading this.)

MORE: These beaches glow neon blue in the middle of the night — here’s why

UP NEXT: Sea turtles are hatching around the world — here’s how they make it to the ocean

Ghost bats

The ghost bat is also known as the false vampire bat. It is about 4.3 inches long and weighs anywhere from 74 to 144 grams, which actually makes it ones of the biggest bats in the world. It has large eyes, a leaf-shaped nose and very large ears that are joined together above its head. Its fur is very light brown or gray, and some appear to be almost white. It does not have a tail. 

The ghost bat eats insects, reptiles, frogs, birds, small mammals, and even occasionally other bat species. The ghost bat lives in small colonies in arid and rainforest regions around the world.

There are less than 10,000 total individuals left in the world. Its population has decreased over the last 100 years due to mining, which disturbs roost sites in caves. The ghost bat also only produces one offspring every year, making any recovery efforts for their species slow. 

Bumblebee bats

Only about 1.1 inches long, the bumblebee bat is the smallest mammal in the world. It weighs only 2 grams. In fact, it is so small that it is actually about the same size as a bumblebee, explaining its name.

The Bumblebee bat is reddish-brown to gray in color, with a pig-like nose, large ears, and tiny eyes. It has relatively long forearms (1 inch) that helps it achieve a special trick: hover mid-air like hummingbirds. It eats flies and spiders.

The bumblebee bat lives in groups of varying size (from 10 up to 500) inside limestone caves within evergreen or deciduous forests in Thailand and Myanmar. The species was first discovered in 1974, but today the bumblebee bat is endangered and its population is declining.  It has become an attraction for collectors and tourists who want to catch a glimpse of this tiny creature.  The burning of forests near the caves where it lives is also threatening its survival.  

Hammer-headed bats

Hammer-headed bats are the largest bats in Africa.  They live in the swamps, mangroves, and palm forests of central Africa. 

They show strong sexual dimorphism, meaning males and females are very different looking from one another. Both males and females have large, square-shaped heads, brown fur with a white collar, and a large, flexible thumb. But males are bigger and have large lips, warty snouts, and a split chin with cheek pouches. 

These bats eat the juice of mangoes, bananas, and guavas. They mate in an arena type setting — 25 to 130 bats will gather along tree branches by the river at night to mate. 

The good news is that hammer-headed bats are under no special conservation status and their numbers are currently sustainable. 

Everyone knows "Parmesan cheese"— or at least they think they do.

In the US, we frequently think of it as the stuff we grate or worse, buy grated to put on pasta.

Largely, that's because in this country, the arbiters of US trademark law have decided that "Parmesan" is a generic term, explains Larry Olmsted in his new book, "Real Food/Fake Food: Why You Don't Know What You're Eating and What You Can Do about It." We call Parmesan generic, despite the fact that the name of the Italian cheese that translates to Parmesan, Parmigiano-Reggiano, is a protected name that can only be used for cheese that's prepared in an incredibly specific way and comes from the region around the Italian city of Parma.

That authentic cheese, Olmsted explains, is a truly special product. The cows that produce the milk can only eat grass and hay from pure pastures and cannot receive antibiotics or supplements. The cheesemaking process must begin within 18 hours of milking, and the cheese can only include milk, rennet (a naturally occurring complex of enzymes used to make cheese), and salt. A standard-sized wheel of cheese is produced, one that hasn't changed for hundreds of years, and it must be cared for and aged for at least one year before it's sold.

Meanwhile, in the US, all kinds of cheese are passed off as Parmesan. In restaurants or pre-grated packages they may be other hard cheeses, like Pecorino Romano or Gran Padano. Others are imitations made here that have little in common with the real thing. In the worst cases, they may not even be cheese. As a particularly bad scandal earlier this year revealed, some of those canisters of cheese contained cellulose, or wood pulp. 

Olmsted tells Tech Insider that the sometimes sensationalized scandals aside, the real tragedy is that people don't know what they're missing when they get a low quality imitation of a truly good food.

"It’s the real foods that are really important," he says. "They’re being knocked off because they’re good."

Even in the case where it's "legal" to produce these imitations of Parmesan, they'll never have the flavor of the real stuff, which breaks apart when pressed with a knife to reveal crumbles of cheese filled with intense and salty crystals of flavor. 

In the case of Parmesan, these legal imitations won't harm anyone physically. But they do affect the reputation and livelihood of the people who dedicate their lives to making these foods. Perhaps even more importantly, the bland imitations of food created largely by our system of mass-production are largely flavorless, which is why sugar and salt are frequently poured into processed foods.

This does affect people's health and it takes away an appreciation for how special those "real foods" are. That's relevant to foods like Parmesan cheese and olive oil, but it's also the case for something as simple as a tomato. A mushy, bland, supermarket tomato just teaches you that they're not worth thinking about; a rich, fully flavored heirloom tomato can make you re-think what those vegetables have to offer.

After appreciating those real foods, it's much easier to see why eating a healthy diet isn't just some boring "eat your vegetables" line — it's actually a transformative delight that can be the highlight of a day.

"When people are used to a certain level of mediocrity, they don't know how much better it can be," says Olmsted.

SEE ALSO: Expert reveals 3 expensive restaurant foods that are often fake

Join the conversation about this story »

NOW WATCH: How a physicist solved one of the greatest baseball mysteries of the early 20th century

As much as 10% of the food you encounter in supermarkets and restaurants may not be what you think it is.

Many of the food items you might think of as basic staples represent the leading categories for fraudulent or counterfeit food. Ground coffee and bagged tea may contain leaves, twigs, sawdust, or cereals. Juices frequently aren't made of what they're advertised to be.

So how do you avoid buying bogus versions of the food you want?

Larry Olmsted, author of the new book "Real Food/Fake Food: Why You Don't Know What You're Eating and What You Can Do about It," has a simple piece of advice for anyone that's concerned:

"The biggest sort of overarching tip is just try to buy the food as close as you can to the whole form— as in intact — as you can," he tells Tech Insider.

Whole bean coffee can't contain the same non-coffee filler materials that might be found in the pre-ground stuff. In 2013, certain samples of "beef" sold in Europe were found to be 80%-100% horse meat — but the horse was ending up in pre-made "beef" lasagnas, not in much more easily identifiable steaks. Cheap lobster rolls or lobster ravioli aren't likely to be filled with the real thing, but you know what you're getting with a whole lobster. If you buy whole fruit instead of juice, you'll get the real flavor that you want and it's a healthier way to go.

Of course, this one tip doesn't always help with something like extra-virgin olive oil, which is often full of lower quality oil, sometimes not even from olives. It doesn't help distinguish real honey from fake stuff filled with corn syrup.

But in those cases, Olmsted recommends looking for trusted local producers (in the case of honey) or in the case of something like olive oil, seals of approval from respected organizations like the California Olive Oil Council, the Extra Virgin Alliance, or UNAPROL.

There's tons of delicious food out there. If you stick to the whole versions of it or look for trusted sources, you'll be able to get the best of it.

Join the conversation about this story »

NOW WATCH: 9 phrases on your résumé that make hiring managers cringe

This weekend is set to be one of the hottest of the summer.

Our bodies can do a lot for us to help us deal with the heat, such as sweating to reduce our core temperature. But one thing it can't do is provide us with a self-made beverage to quench our thirst.

That's right — even though saliva is made up of around 98% water, it simply can't give us the same benefits as drinking a glass of water. This seems a little counterintuitive considering our salivary glands produce up to two liters of liquid a day.

Dr. Len Horovitz at New York City's Lenox Hill Hospital told LiveScience that the reason saliva can't hydrate us is because it is concentrated with things such as proteins, enzymes, and electrolytes — much more so than the water we drink.

This causes a problem with osmosis, which is when two liquids of different concentrations are separated by a membrane (such as the membranes of our cells), the liquid with the lower concentration flows in the direction of the liquid with the higher concentration in an attempt to even out the concentration levels of both.

Since fresh water is much less concentrated with salts and other solutes than the fluids in our body, when we drink it, our body's cells are able to absorb it via osmosis, resulting in that satisfying feeling of a quenched thirst.

But the concentration of saliva is too high, so it can't be absorbed by osmosis. In fact, if we drink it, it will likely make us feel thirstier because it is actually more concentrated than our body's fluids.

To make matters worse, when it's hot out, our saliva becomes even more concentrated when our bodies start to lose water through sweat.

So while desperation might lead people to try to swallow their own saliva to satisfy their thirst, it simply is never going to work. The best bet this weekend — and during any hot weather — is to always keep a water bottle handy and stay hydrated.

MORE: Officials are now investigating what might be the first 2 cases of Zika from a mosquito in Florida

UP NEXT: Here's why it will be so unbearably hot this weekend

Join the conversation about this story »

NOW WATCH: NASA just released a video of what it would be like to land on Pluto, and it's breathtaking

Meet your great-great-great-great-great-great — well, let's just say your very oldest ancestor.

Its name is Luca, short for "last universal common ancestor," and it probably lived near a hydrothermal vent at the bottom of the ocean about four billion years ago.

For the first time, scientists have put together a picture of what it might have looked like genetically. But not everyone is convinced.

The portrait comes from new research published July 25, in which scientists sorted through six million genes to settle on 355 they think Luca may have carried. Genes change in a predictable way over time, which means that comparing the DNA sequences of living organisms lets scientists make hypotheses about organisms we have no other way of studying.

So the scientists, led by William Martin at Heinrich Heine University in Germany, looked at genes from bacteria and archaea: the two large umbrella groups of single-celled life. Genes that could be found in at least two groups of bacteria and two groups of archaea were considered likely to have belonged to Luca.

The 355 genes the researchers picked out suggest Luca survived without oxygen, pulling energy from carbon dioxide and hydrogen instead, that it could survive very high temperatures, and that it required the presence of metals. Scientists have long wondered if life might have begun near hydrothermal vents — places where seawater is heated by hot magma, and unusual microscopic organisms thrive. The picture the new paper paints of Luca matches that lifestyle quite well.

But scientists disagree about where exactly these features would place Luca on the timeline of early organisms. Some of its tricks are quite difficult to accomplish, but it's missing other characteristics considered critically important for life. It carries only a small number of tools to construct amino acids and nucleotides, for example, which are key building blocks for life as we know it.

Either way, scientists are gathering more clues about some of the earliest lifeforms. They may seem simple and almost alien, but these ancient ancestors eventually developed into humans — and everything else that lives on Earth.

Join the conversation about this story »

NOW WATCH: Archaeologists made a groundbreaking discovery that unveils the mysterious origins of real-life hobbits

On July 5, 1996, Dolly the sheep became the world's first ovine (sheepy) superstar.

She was the first mammal successfully cloned from an adult cell, ushering in an era where you can special-order cloned puppies or elite polo horses.

But scientists were also concerned that Dolly could be a cautionary tale: Genetic testing revealed that her DNA showed signs of aging at just one year old, and at 5, she was diagnosed with arthritis. It wasn't clear whether Dolly's problems were because she was a clone.

Dolly eventually died after being diagnosed with a virus in 2003 at six years old — half the typical life expectancy of a sheep of her kind.

"We're presented with a blank slate in a way," researcher David Gardner said during a press conference in the UK on Monday. "We wanted to assess these animals' physiology to see if they're normal."

As it turns out, Dolly may have just gotten a bad shake. Researchers at the University of Nottingham announced Tuesday that four clones derived from Dolly's cell line are alive and healthy at nine years old.

The four "Nottingham Dollies," as they've been dubbed by their keepers at the Roslin Institute, are the only survivors from a group of 10 Dolly clones born in 2007.

They were raised alongside nine other non-Dolly clones and regular sheep in order to measure their metabolic, cardiovascular, and musculoskeletal health. Despite Dolly's seemingly premature aging in her joints, only one of the four clones, Debbie, showed moderate arthritis.

"Metabolically and cardiovascular-wise, they were indistinguishable from other sheep of that age," veterinarian and collaborator Sandra Corr told the press. "We found that the majority of sheep were really very healthy considering their age."

The are also incredibly soothing to watch.

The idea that five clones could all develop arthritis differently and at different ages is a tantalizing hint in the search to teasing out how epigenetics, or factors that affect how genes are expressed, influence the life of an organism.

The sheep were all cloned using the same method that created Dolly, called somatic-cell nuclear transfer.

In this process, scientists remove the DNA (located in the nucleus of a cell) from the mammary gland of an original sheep, then transfer it into the nucleus of an egg cell. Next they give this new egg cell a small jolt — in the case of the surviving Dollies, caffeine — which triggers the cell to start dividing until it becomes a viable embryo.

As cells mature, they differentiate. A skin cell, for example, is different from a lung cell. Part of what made Dolly's successful birth so remarkable is that scientists were able to "reset" those differentiated cells back to undifferentiated cells so they could grow into an entirely new lamb.

This is the most in-depth study of health of clones over their lifespan, according to lead researcher Kevin Sinclair in a video released by the University of Nottingham. (Sinclair took over the project after his predecessor Keith Campbell, who cloned the sheep nine years ago, passed away in 2012.)

So far, the Dollies' good health — helped along by a lifestyle most farmed sheep would likely consider luxurious — is an indication that clones can live long, healthy lives.

"Were cloning to accelerate aging, we would've seen it in this group," Sinclair told the press on Monday.

Watch Sinclair give more details on the life of the Nottingham Dollies below.

MORE: The 'generic' version of this popular drug could be dangerous

UP NEXT: 13 of the hottest places on Earth

Join the conversation about this story »

NOW WATCH: We visited a one-of-a-kind lab in South Korea that will clone your dog for $100,000

On Tuesday scientists told the world that four clones of Dolly the sheep, known as the Nottingham Dollies, are alive and in good health.

In fact, they're almost indistinguishable from non-cloned sheep of similar ages and each other.

Almost.

Dianna, Daisy, Denise, and Debbie have none of the premature aging scientists feared might result from the cloning process — just a little arthritis, or, in the case of Debbie, moderate arthritis.

(Dolly, who was the first successfully cloned animal, developed severe osteoarthritis at age five.)

So why aren't the Nottingham Dollies — and the original Dolly — exact copies?

It's likely the same and important reason why Debbie the Dollie has more advanced osteoarthritis than her sisters, who are from the same "batch" of Dolly clones and were raised alongside her: epigenetics.

Epigenetics is how geneticists describe subtle but crucial differences in gene expression. DNA often contains genes that aren't expressed — essentially genes that are switched to the "off" position. We know that those switches can flip to "on," but it seems to be linked to environment and experiences.

The Dollies, biologist Kevin Sinclair told reporters at a press conference on Monday, could give us insight into "the extent of epigenetics reprogramming," or how identical genetic sequences lead to different results. Especially since the cloned sheep were all raised together and cared for in the same place.

Epigenetic factors have been linked to obesity, heart disease, and cancer, along with many other diseases and disorders. So if we can understand why Debbie and Dolly got arthritis and their sisters didn't, we're one step closer to understanding how those genes express themselves differently within ourselves, even given similar upbringing.

And why did Dolly die at six years old while her clone sisters have gracefully reached a twilight age of nine years? (Dolly and the Dollies are Finn Dorset sheep, which can live up to 12 years.)

This story, unfortunately, is a sad one.

Dolly became infected with a virus unique to sheep that caused tumors to grow in her lungs. On discovering several tumors, her keepers realized that euthanasia was the most humane option. Dolly the sheep died peacefully in her sleep at six years old.

SEE ALSO: Scientists have finally discovered why no adult can remember being a baby

Join the conversation about this story »

NOW WATCH: Scientists are trying to clone a lion that became extinct 12,500 years ago

If you spend all day sitting down for work — and also while commuting or even relaxing — no doubt you are aware that your sedentary lifestyle is killing you.

But according to a new analysis of studies of this subject, published July 27 in the Lancet, you may actually be able to counteract most or even almost all the negative effects of sitting with enough exercise.

This is both a big deal and surprise. While we've known that exercise has profound effects and can add years to your life, a lot of previous research has shown that even people who meet the US government's recommendations for physical activity can't eliminate the increased risk of early death that's associated with sitting all day.

The catch with the new study is that you have to work out more than most any country's fitness guidelines recommend. The CDC's current fitness guidelines for adults call for at least two and half hours of moderate intensity activity plus at least two muscle-strengthening days a week — a total of about 30 minutes every day. Right now, only 20% of people meet that goal.

But the new review, which included data from 16 studies that followed more than a million people over time, found that people who got at a minimum of 60 to 75 minutes of moderate intensity exercise a day didn't have a significantly increased risk of death compared the baseline group, even if they sat for more than eight hours a day. The baseline group of people sat less than four hours a day and got that minimum of 60 to 75 minutes of exercise.

People who watch more than five hours of television a day also have a dramatically increased risk of early death compared to that baseline group. For people who work out more than an hour a day and yet still watch this much TV, almost all of that increased death risk disappears, but not quite all.

More than an hour of moderately intense exercise each day might sound like a lot, especially for the 80% of people that don't meet current guidelines, but it doesn't take too much to qualify. Brisk walking and moderate cycling count as "moderate intensity exercise."

Why exercise is such a big deal

This analysis can only find associations; it can't tell you cause and effect. People who are especially sedentary have an especially high likelihood of dying sooner because of diabetes, heart disease, or other illnesses. Based on these studies, we know that for people who get a good amount of moderate intensity exercise, that increased risk almost entirely disappears.

After controlling for other possible causes, the researchers think exercise is the reason why.

Other aspects of their data support the idea that exercise is important too. People who don't exercise (less than five minutes a day) but who also sit the least (less than four hours a day) have a much higher risk of death than people in the baseline group.

Digging into the findings

The following two charts help break it down.

This first one breaks down the study populations into four categories based on how much they exercise and then shows people's increased risk of death (y-axis) compared to how much they sit each day. You can read the exercise reference categories from left to right as "at least 60-75 minutes of moderate intensity exercise each day," 50-65 minutes of moderate intensity exercise, 25-35 minutes of moderate intensity exercise, and less than five minutes of exercise a day.

As you can see in the above chart, people who worked out the most had essentially no increased risk of death, while not exercising at all and sitting more than eight hours a day was associated with a more than 50% increase in death risk. The more people exercised, the better.

The following chart compares exercise time to time spent watching TV.

The data here was a little bit more variable, possibly because there was less of it, according to the study. But the general trend still applies. Spending a lot of time watching TV is associated with a higher risk of death. The more you work out, the less increased risk there seems to be. But if you watch more than five hours of television a day, that risk never fully disappears, even if you are among the most active group.

The takeaway? You're in control

The takeaway from this massive review is both a simple and hopeful one. Behavior can make a difference, even if our modern lives are inherently unhealthy, and that's a great thing to hear.

"There has been a lot of concern about the health risks associated with today's more sedentary lifestyles," lead study author Professor Ulf Ekelund, from the Norwegian School of Sports Sciences, Norway and the University of Cambridge, says in a press release. "Our message is a positive one: it is possible to reduce — or even eliminate — these risks if we are active enough, even without having to take up sports or go to the gym."

Just walking or biking does the trick.

Ekelund adds: "For many people who commute to work and have office-based jobs, there is no way to escape sitting for prolonged periods of time. For these people in particular, we cannot stress enough the importance of getting exercise, whether it's getting out for a walk at lunchtime, going for a run in the morning or cycling to work. An hour of physical activity per day is the ideal, but if this is unmanageable, then at least doing some exercise each day can help reduce the risk."

So get moving.

Join the conversation about this story »

NOW WATCH: The science behind the latest advance in fireworks design

Scientists aboard the Ocean Exploration Trust’s Nautilus research vessel came across a mysterious, purple blob when their remotely operated vehicle was exploring the Pacific Ocean off the coast of California. They aren’t sure what it is.

Video courtesy of Ocean Exploration Trust.

Follow TI:On Facebook

MORE: Scientists have found a way to predict whether fisheries are vulnerable to climate change

UP NEXT: It’s International Tiger Day — here is everything you ever wanted to know about these stunning, wild cats

Join the conversation about this story »