TIME archeology

The Mystery of a 8,000-Year-Old Skeleton Has Been Solved

KENNEWICK MAN SKULL
Elaine Thompson—AP A plastic casting of a controversial 9,200-year-old skull sits in the basement of archaeologist James Chatter's home July 24, 1997 in Richland, Wash.

He may have lived a simple life back then, but Kennewick Man’s remains have sparked controversy and legal battles that the latest scientific investigation may finally put to rest

Finding a human skull doesn’t happen often, but the skull that two college students stumbled upon in the Columbia River in 1996 proved rarer still. It happened to belong to an ancestor that roamed North America nearly 8500 years ago. Near the skull were remains of practically an entire skeleton belonging to a male who was likely buried along the riverbank by his people in Kennewick, Washington.

Kennewick Man, as he is known, quickly became the subject of a custody battle between scientists eager to study his remains, which are among the oldest and most complete of a human ancestor in North America, and a group of five Native American tribes who claimed the bones as the Ancient One, one of their own forebears. The U.S. Army Corps of Engineers, which manages the land on which the remains were found, intended to return the ancient bones to the Native Americans. The archeologists sued for the right to study them, and in 2004, a judge ruled that the fossils should be studied further.

MORE: Ice Age Infant’s Genes Show That Native Americans First Came From Asia

The results of that analysis were published in a popular book that detailed the lifestyle that Kennewick Man likely led, but since then, advances in genetic sequencing made it possible to do a complete genome study of his DNA. And those results, published in the journal Nature, resolve a long-standing dispute over where Kennewick Man came from — Europe or Asia, or whether he was, as the Native American tribes claimed, an early ancestor who gave rise to some of the Native American populations that subsequently resided in North America.

His genes show that Kennewick Man was more closely related to Native Americans than to European or Asian populations. “It’s very clear the genome sequence shows that he is most closely related to contemporary Native Americans,” says Eske Willerslev, from the Center for GeoGenetics at the University of Copenhagen, who led the analysis.

MORE: A Tale Told by Ancient Bones

Hints of these results first leaked in January, when emails obtained from a Freedom of Information Act request by reporters at the Seattle Times revealed that Willerslev’s group shared some of their early findings with the Army Corps of Engineers to update them on the genetic analysis, which was done in Copenhagen. And presumably, it puts to rest any lingering questions about Kennewick Man’s origins.

Those began when the first archeologist to evaluate the skull’s anatomical features declared it to be more Caucasian than Native American, and continued when Douglas Owsley, a physical anthropologist at the Smithsonian Institution who is considered the expert on North American human remains, agreed with that conclusion. Owsley pointed out that the prominent forehead of Kennewick Man and thinner brain case made him more like Japanese Ainu or Polynesians rather than Native Americans.

His genes tell a different story, however, and when Willerslev’s group also compared Kennewick Man’s DNA to that of the Ainu, Polynesians and Europeans, they found that it did not share the same similarities as it did with those of the contemporary Colville, a Native American tribe from the Columbia River area that agreed to provide DNA samples. No other Native American groups provided genetic material, so it’s possible that other tribes have an even closer connection to the ancient remains than the Colville.

The results do not show that Kennewick Man was a direct ancestor of any tribe living today, says Willerslev. It’s not known whether, for example, an older population of Native Americans living in North America then split into a branch that led to Kennewick Man, and another to the contemporary tribes such as the Colville, or whether Kennewick Man is the ancestor of the Colville and other modern Native Americans.

The genetic analysis does little to change archeologists’ current theories about the first North Americans. The first people to spread into the Americas likely came 5,000 to 6,000 years before Kennewick Man’s time, probably from Siberia via a now non-existent land bridge that allowed them to traverse the Bering Strait.

As for Kennewick Man’s future, Willerslev says that he has been in contact with several members of the Colville throughout the analysis and says that “To me, they seemed pretty excited, and found it interesting.” Whether the remains will now go back to the Native American groups under the Native American Graves Protection and Repatriation Act isn’t clear. But Willerslev acknowledges the irony in the findings. “The reason why we came to this conclusion scientifically speaking is because the remains were almost kept out of science,” he says.

TIME medicine

Scientists Find a Gene That Regulates Sleep

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Vincent Besnault—Getty Images

It's a study in flies but it could have implications for us, too

Flies, it turns out, sleep about as much as young children do. Males need about 12 hours a day, while females can do with about 10 hours. To find out which genes might be responsible for guiding how much slumber flies get a night, Kyunghee Koh did a massive experiment that you can only do with fruit flies.

She and her team at Thomas Jefferson University reported in the journal Current Biology that they took 3,000 flies, introduced random mutations in them and then monitored how well they slept. That allowed them to zero in on the genes that most directly affected slumber, and they found one, taranis, that may become an important target for sleep-related research even in people.

Flies with abnormal forms of taranis only get about 25% of their daily sleep; removing the gene keeps the flies buzzing almost non stop.

Koh’s team found that taranis works with a couple of other proteins to balance sleeping and waking. Normally, taranis and cyclin A pair up to keep the activity of another enzyme down. That enzyme generally keeps the flies awake. So when all three are working in concert, taranis and cyclin A shut down the enzyme so flies can get 10 to 12 hours of sleep. But when taranis is mutated, it doesn’t do its job as well, and the enzyme keeps the flies alert and unable to sleep.

It turns out that taranis has a related gene in mammals that may work in similar ways. The gene typically controls the way cells divide, “We don’t know yet whether these genes have a role in sleep in mammals or humans, but our hope is that somehow these genes we find in flies may have similar roles in people, and might ultimately give us some novel drug targets to help us sleep better,” says Koh.

TIME Diet/Nutrition

This Kind of Fat Messes With Your Memory

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Samuel Kessler—Getty Images

These fats can build up in artery walls and spell disaster for the heart, but they can also harm the brain

The latest study gives support to the Food and Drug Administration’s (FDA) decision to phase out the fats in three years. In a report published Wednesday in the journal PLOS One, researchers say that eating any amount of trans fats, such as those found in processed baked goods and cookies and some margarines, can wreak havoc on your memory.

Dr. Beatrice Golomb, professor of medicine at University of California San Diego, and her colleagues analyzed diet information on 1018 healthy men and women who were part of a study on cholesterol-lowering drugs. The participants answered detailed information about what they ate, including how their food was prepared, and the scientists then calculated the amount of trans fats the volunteers consumed based on their responses. Each participant also took part in a word recall test to measure their memory; they were presented with a series of word cards; the first time they saw a set of 104 cards, then they saw another set in which only 22 words remained the same, and were asked to identify which were new and which were repeats.

MORE: This Is Why FDA Is Banning Trans Fats

When the researchers matched up trans fat consumption with performance on the memory test, they found that those with the highest trans fat in their diet labeled the most words incorrectly. And, this effect seemed to be worse among younger volunteers than older ones.

“These results fit with other work showing that trans fats are key to brain function, including mood and behavior,” says Golomb. “And now we have another outcome showing that they adversely impair cell energy and oxidative stress.”

MORE: You’re Eating More Trans Fat Than You Think, Study Finds

While her study didn’t delve into how the trans fats are impeding memory, there is ample evidence that trans fats promote oxidative damage to cells. The presence of the fats can lead to a higher level of unstable oxygen molecules which can in turn destabilize DNA, proteins and other fats, prompting affected cells to die off. Some studies show that the memory center of the brain, in the hippocampus, is particularly vulnerable to such changes, which could explain the results Golomb saw.

The fact that the younger participants seemed to show worse effects than older ones may simply reflect the fact that older people are already experiencing declines in memory due to other, cumulative effects of brain injury, from poor sleep to a lifetime of traumatic injuries. In older people, the difference in memory changes won’t be as robust as they are in younger people.

MORE: Trans Fats Are Hiding All Over Your Grocery List

Essentially, for every gram per day of dietary trans fat the participants ate, the volunteers were able to accurately recall 0.76 fewer words. The FDA currently allows companies whose products contain 0.5g of trans fats to label them as having zero trans fats; even if a person eats eight such products (a reasonable amount, considering they’re found in canned chili, frozen cheesecake and popcorn) for a total of 8g of trans fats, that would mean they might remember three fewer words on the memory test on average. “That association does not appear to be tiny in my view,” says Golomb.

“There is no good consumption or exposure level; there is no positive purpose in my view of trans fat consumption,” says Gololmb.

The FDA, it seems, finally agrees.

TIME Infectious Disease

South Korea’s Latest Fashion Accessory: Face Masks

Residents of the country’s densely packed capital are relying on face masks for protection. But how effective are they?

It may be more psychological than logical. Everyone from school children to the nation’s famously fashion-forward teens are covering up in the face of MERS, or Middle East Respiratory Syndrome, a coronavirus that aims straight for the lungs and makes breathing a challenge. The culprit? Virus particles that spread between people who are in close contact, presumably from saliva and secretions that are released when people cough or sneeze.

Most cases, including the 154 reported so far in South Korea, are spread from infected patients in hospitals to health care personnel or close caregivers. But that hasn’t stopped Korean residents from buying out the supply of face masks in the capital city of Seoul, where the first patient sough medical care after becoming ill.

According to the U.S. Centers for Disease Control and Prevention, health care personnel or others who come in contact with MERS patients should wear something called an N-95 respirator, which has a disposable, fitted facepiece filter that can prevent users from breathing in droplets that may contain the virus.

Paper face masks, which fit loosely over the face, can also block large droplets or splatter but can’t completely prevent someone from inhaling viruses, especially if they are in close contact with an infected person for a relatively long time. Public areas in South Korea aren’t particularly high-risk locales, but the idea that some barrier is better than no barrier is likely driving the sales of these masks, some of which come adorned with popular cartoon characters and other logos. It’s also an extension of the Asian habit of donning masks when you’re sick—not so much to protect yourself from getting infected with something, but to prevent you from infecting others.

Read next: This Photo Symbolizes Just How Much MERS Is Taking Over South Korea

TIME Aging

This Is When Women Using IVF Should Consider Donor Eggs

The latest study says success rates decline considerably after this age

In a report presented at the European Society of Human Reproduction and Embryology, researchers provided some much-needed information that they hope will help couples using IVF to make more informed decisions about how best to use the reproductive technology.

Infertility increases with age, and while there are many reasons why couples have a hard time conceiving, one important contribution is the quality of the woman’s eggs. Because women are born with all of the eggs they use throughout their lifetime, the older the eggs are, the more vulnerable they are to developing genetic and other abnormalities that make them weaker candidates for getting fertilized by sperm and developing into a healthy baby.

But at what age does this process truly decline? Most reproductive data shows that live birth rates start to decline when the woman reaches 35, so Dr. Marta Devesa from the department of obstetrics and gynecology at Women’s Health Dexeus in Barcelona, Spain and her colleagues decided to analyze birth rates by age and whether women used fresh or frozen embryos in their IVF cycle. They found that the cumulative live birth rate—which includes every transfer of an embryo from a single stimulation cycle (most women produce multiple eggs and many of these are fertilized to become embryos, one of which is usually transferred to the womb and the rest of which are frozen for future transfer)—dropped with age.

MORE: Exclusive: Meet the World’s First Baby Born With an Assist from Stem Cells

But they also learned that the live birth rate was really driven by the first transfer of the fresh embryo, and wasn’t significantly increased by transferring additional frozen embryos if the first transfer didn’t result in a pregnancy. In other words, the first, fresh embryo provides the best chance for pregnancy, particularly in women age 42 or older. “The benefit from the frozen embryos is very limited,” says Devesa.

The findings don’t suggest that freezing embryos isn’t worth the effort or the cost, however. For women ages 38-39, the extra benefit from transferring frozen embryos a live birth was 13%; for women ages 40-41, 9%, and for women 42-43, 2%. For women 42 years or older, the frozen embryos only added a 1% increased chance of a live birth. For them, their chances of pregnancy may be higher with a donor egg.

The number of embryos may also be an indicator of a couple’s chances of having a baby. “If we have more embryos to freeze, the live birth rate from the fresh embryo is significantly higher than if we didn’t have any embryos to freeze,” she says. “Why? Because more embryos means we have a better chance of selecting the best embryo.”

The findings, she hopes, will help doctors and patients to better assess their chances of pregnancy and provide more accurate information for couples about whether they should continue with IVF using their own eggs and sperm and when they should consider using donor eggs. While each couple decides on how they want to proceed with IVF, with the current findings, “at least we can give them real expectations about their chances of a live birth, so they can manage their expectations correctly and properly,” Devesa says.

TIME Cancer

Researchers Grow a Breast In a Dish

Technically, it’s breast tissue but it develops in a lab culture the same way it would in a teen hitting puberty. And it could help scientists to better understand how the breast develops and what happens when things go awry in breast cancer

For the first time, scientists have taken healthy breast cells from women and isolated the stem cells that can recreate major breast structures—including the milk-feeding ducts and structures that actually produce breast milk. In a new paper in the journal Development, they report that they’ve set up a model for studying how normal breast tissue develops during puberty, and, in coming months, expect to introduce mutations in these cells to study how they might develop cancer.

Starting with breast tissue from women who have had breast reduction surgery, Dr. Christina Scheel, from the Helmholtz Center for Health and Environmental Research, and her colleagues managed to isolate the few stem cells within them that are responsible for generating the new breast tissue that results in the breast’s constant remodeling during puberty, at each menstrual cycle and with each pregnancy.

Only one in about 2,000 of these cells are stem cells, but by mixing up a more nurturing culture solution, they were able to increase the growth of these cells by five-fold, and before their eyes the cells began to form the branchlike structures that serve as the duct network of the breast. With other adjustments, Scheel was also able to promote the growth of the cluster-like cells that produce milk. By labeling the initial stem cell, they saw that all of the complex structures in the breast remarkably arose from a single cell, guided by the right developmental instructions.

“[During puberty,] the normal breast tissue grows [aggressively] into the surrounding connective tissue,” says Scheel. “The cells push forward into the surrounding tissue almost like an invasive tumor but in a very controlled process.”

The fact that the normal breast tissue growth is so intense is leading Scheel to next study whether breast cancer might result from some loss of this very controlled regulation of breast tissue growth, similar to a car without brakes.

She and her team also found that when they grew the breast stem cells on a more rigid platform, the cells grew more aggressively and acted more tumor-like compared to when they were grown on a more flexible, softer framework. That may explain why women with dense breasts, which contain more connective tissue, tend to have higher rates of breast cancer. “This model will allow us to better study normal breast development, and then to understand the first steps that predispose women to developing tumors,” she says.

TIME medicine

5 Ways to Make Binge Watching Less Terrible for You

Your brain will undoubtedly thank you for the one benefit of binge watching — not having to wait in suspense to see what happens next. But your body might not be so forgiving.

It’s time for season three of Orange Is the New Black on Netflix, so we know where most of you will be this weekend. If you must get your OITNB dose in one mammoth session on your couch, here’s some advice on how to break it up so at least some of health harms from all that sitting—the perils of which cannot be overstated—don’t come back to haunt you.

Get up halfway through each episode.

The latest data shows that getting up every 30 minutes (whether you’re binge watching or at your desk at work) can keep your metabolism from flagging and your heart muscle from getting too relaxed. You don’t have to run a mile but getting up and walking upstairs or downstairs can get your circulation going.

Go easy on the snacks.

Just keep enough around you to keep you sated through the next half hour—because, per above, you’ll be getting up anyway. But don’t eat nonstop, either. Have episode-on, episode-off rules for eating.

Don’t eat just chips and pizza and beer.

If it’s impossible to avoid the binge-watching staples, at least mix in a few fruits and nuts—which just got another thumbs up from a health perspective, or these veggies that are even healthier than kale. That will keep your taste buds occupied too and you won’t get bored eating the same thing for hours. And in case you are so inclined to snack on fries, read this: Should I Eat French Fries?

Drink water.

Side benefit — it will make you want to go to the bathroom more often, and that will force you to get up (see above). Skip soda, juice and even seemingly healthy beverages like coconut water and just grab yours from the tap. You, like most American kids, probably aren’t drinking enough of the stuff anyway.

Do something physical for 1 minute whenever your favorite character comes on.

Think of it like a drinking game, but with exercise. Use each appearance of your favorite prisoner to do a minute of jumping jacks. Or squats. Or lunges. Anything, in other words, that gets you off your butt and moving. Recent research shows that micro-workouts as short as 1 minute make a big difference when you add it all up.

TIME Diet/Nutrition

Mom’s Diet During Pregnancy Can Affect Child’s Lifetime Cancer Risk

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Getty Images

Expectant mother’s nutrition during pregnancy can have lasting effects on their children’s health, especially when it comes to cancer risk

In a new report published in the journal Genome Biology, researchers combed the genome to find regions that are particularly vulnerable to outside influences, such as diet, nutrition and environmental exposures, to determine how these factors might affect a developing fetus.

While the genes encoded in every person’s genome determines his characteristics, a second layer of genetic activity, called epigenetics, controls which genes are turned on and which are shut off, at different times in different cells. It’s epigenetics that is responsible for ensuring that a hair cell becomes a hair cell and not a liver cell, and so on. For the most part, these instructions are set during early development in the embryo.

But, as Robert Waterland, associate professor of pediatrics and molecular and human genetics at Baylor College of Medicine and his team found, there are discrete places in the genome where epigenetic changes are more vulnerable to external influences like diet. They conducted a genome-wide survey to find these regions, and then tried to match them up with easily measurable factors such as nutrition or mothers’ diets.

They did this in a population of women in Gambia, where changing seasonal availability of food allowed them to compare women who conceived during times when food was scarce, to those who conceived when crops were more abundant. Indeed, they honed in on a specific variant in a gene that is involved in suppressing tumors. When this gene is epigenetically activated, it leads to protection against cancer, but may lead to lower immune system function and this activation is influenced by a mother’s nutrition. Lower levels of vitamin B2 may contribute to inceeased cancer suppressing activity, and that may establish an lower risk for cancer among children while they are still in the womb.

“Very different maternal nutritional status nudges the distribution of the epigenetic state in one direction or the other,” says Waterland. “In the next phase of research we want to directly test whether individual epigenetic variations in fact leads to changes in the risk of diseases included cancer and immune-related conditions.”

What’s encouraging about the findings is the fact that in addition to the gene they studied in detail, the scientists also found 108 other genes that might be influenced by factors such as diet. Other such external contributors that Waterland is hoping to investigate are things such as mother’s obesity and the effect of IVF, in addition to environmental contaminants such as pollution or cigarette smoke.

TIME Brain

Mental and Social Activity Delays the Symptoms of Alzheimer’s

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Rich Seymour—Getty Images

There’s evidence that such activities do little to change the underlying drivers of Alzheimer’s, but doctors say they delay symptoms

Among the many frustrations surrounding an Alzheimer’s diagnosis is the fact that there is little that patients can do to halt or treat the disease. While promising drugs are under development, the only advice physicians give patients is to stay as mentally active as they can — by learning new languages, reading, piquing the brain with puzzles, and maintaining their social life. Such constant stimulation is supposed to keep the healthy parts of the brain as unaffected by the disease for as long as possible. There’s also evidence that a lifetime of such activity can build up so-called reserves, which can compensate for brain functions when Alzheimer’s sets in.

In a report published in the journal Neurology, Dr. Keith Johnson from Massachusetts General Hospital and Harvard Medical School and his colleagues reveal that people who report higher levels of intellectual stimulation throughout their lifetimes don’t actually exhibit lower levels of protein plaques and other signs of Alzheimer’s compared to those who don’t. But they also found that staying mentally and socially active can push back the appearance of memory problems and other symptoms of Alzheimer’s.

So while the results don’t show that mental activity can affect the biology of Alzheimer’s in any way, it can have a meaningful impact on symptoms. And that is “huge,” says Dr. David Knopman, professor of neurology at Mayo Clinic College of Medicine, who reviewed the paper and recommended it for publication. “If that resulted in a year or two delay in symptoms across the population, that would be a huge effect.”

MORE: Many Doctors Don’t Tell Patients They Have Alzheimer’s

The study involved 186 healthy volunteers with an average age of 74 years who agreed to report their current and past cognitive activities, as well as undergo a brain scan to measure levels of the Alzheimer’s-associated protein called amyloid and the volumes of specific regions of the brain responsible for memory. The group reporting more intellectual activity over their lifetimes did not show lower levels of Alzheimer’s progression as those who reported less cognitive stimulation. But the former group were able to delay the appearance of symptoms, presumably because their stronger intellectual base compensated for the effects of the disease for a longer period of time.

“If two people had the same amount of Alzheimer’s pathology, and one had higher education and engaged in more cognitively stimulating activities, and one had lower educational attainment and didn’t participate in as many mentally stimulating activities, then the symptoms [of Alzheimer’s] would appear earlier in the person with less cognitively stimulating activity,” says Knopman.

MORE: This Alzheimer’s Breakthrough Could Be a Game Changer

While earlier studies relied on studies on autopsy brains to draw connections between cognitive activity and Alzheimer’s disease, this is among the first to investigate the connection in healthy living people, by using state-of-the-art imaging techniques to pick up protein deposits in the brain and following the volunteers to see if any develop the disease. Next up will be studies looking at whether picking up more cognitive activities after an Alzheimer’s diagnosis can have the same effect of slowing memory problems as having a lifetime of such skills.

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