There Are Genetic Differences Between Early Risers and Night Owls

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iStock

Whether or not you’re a morning person may be encoded in your DNA. A team of geneticists from the University of Leicester has identified almost 80 genes in flies that seem to be associated with different circadian rhythms, as they explain in a study published in the journal Frontiers in Neurology.

Fruit flies are often used as model organisms in genetic research because a large portion of their genetic material can also be found in humans. Flies emerge from their pupal case at different times based on their internal clock, with some types of fruit flies making the transition to adulthood at dawn (so-called "larks"), and others late at night ("owls"). Looking at the gene expression of these early risers and night owls, the geneticists were able to pinpoint significant differences in the genetic systems of the two groups, as you can see in this diagram: 

Gene expression levels during the day in fruit flies. Purple represents expression levels above the mean, green below the mean. Image Credit: University of Leicester

Most of the gene expressions that differed between the two groups of flies did not have anything to do with the clock genes that have previously been linked to circadian rhythms. Study author Eran Tauber explains the phenomenon as a kind of pinball machine. 

“Once a gene expression is delayed (in Larks), a completely different cascade of molecular events is carried, similar to the ball in a pinball machine that takes a different route in each run,” he says in a press statement. “The end point might be similar, but the different molecular routes result in a different journey time."

Identifying which genes are involved in the process of regulating the body’s internal clock could one day lead to better treatment for dysfunctional circadian systems, which not only cause sleep issues but have also been implicated in obesity, cancer, and psychiatric disorders

[h/t: Eurekalert]

Does the Full Moon Really Make People Act Crazy?

iStock.com/voraorn
iStock.com/voraorn

Along with Mercury in retrograde, the full moon is a pretty popular scapegoat for bad luck and bizarre behavior. Encounter someone acting strangely? Blame it on the lunar phases! It's said that crime rates increase and emergency rooms are much busier during the full moon (though a 2004 study debunked this claim). Plus, there's that whole werewolf thing. Why would this be? The reasoning is that the Moon, which affects the ocean's tides, probably exerts a similar effect on us, because the human body is made mostly of water.

This belief that the Moon influences behavior is so widely held—reportedly, even 80 percent of nurses and 64 percent of doctors think it's true, according to a 1987 paper published in the Journal of Emergency Medicine [PDF]—that in 2012 a team of researchers at Université Laval's School of Psychology in Canada decided to find out if mental illness and the phases of the Moon are linked [PDF].

To test the theory, the researchers evaluated 771 patients who visited emergency rooms at two hospitals in Montreal between March 2005 and April 2008. The patients chosen complained of chest pains, which doctors could not determine a medical cause for the pains. Many of the patients suffered from panic attacks, anxiety and mood disorders, or suicidal thoughts.

When the researchers compared the time of the visits to the phases of the Moon, they found that there was no link between the incidence of psychological problems and the four lunar phases, with one exception—in the last lunar quarter, anxiety disorders were 32 percent less frequent. "This may be coincidental or due to factors we did not take into account," Dr. Geneviève Belleville, who directed the team of researchers, said. "But one thing is certain: we observed no full-moon or new-moon effect on psychological problems."

So rest easy (or maybe not): If people seem to act crazy during the full Moon, their behavior is likely pretty similar during the rest of the lunar cycle as well.

This story was updated in 2019.

NASA Reveals How Living in Space for a Year Affected Scott Kelly’s Poop

NASA, Getty Images
NASA, Getty Images

When you agree to be part of a yearlong space study, you forfeit some right to privacy. In astronaut Scott Kelly’s case, the changes his body endured while spending a year at the International Space Station (ISS) were carefully analyzed by NASA, then published in a scientific journal for all to see. Kelly submitted blood samples, saliva samples, and cheek swabs. Even his poop was subjected to scrutiny.

As PBS reports, Scott Kelly’s fecal samples revealed that his gut microbiome underwent significant but reversible changes during his time in orbit. In what was surely good news for both Kelly and NASA, his gut bacteria didn’t contain anything “alarming or scary,” according to geneticist Martha Hotz Vitaterna, and it returned to normal within six months of landing on Earth.

Even after being subjected to the challenging conditions of space, “Scott’s microbiome still looked like Scott’s microbiome, just with a space twist on it,” said Vitaterna, who was one of the study’s authors.

The fecal probe was one small part of a sweeping NASA study that was just published in the journal Science, more than three years after Kelly’s return. Dubbed the Twins Study, it hinged on the results of Kelly’s tests being compared with those of his identical twin, retired astronaut Mark Kelly, who remained on Earth as the control subject.

NASA’s goal was to gain insight into the hazards that astronauts could face on proposed long-term missions to the Moon and Mars. The agency has gone to great lengths to get this information, including offering to pay people $18,500 to stay in bed for two months in order to replicate the conditions of anti-gravity.

It also explains why NASA was willing to launch unmanned rockets into space to collect samples of Kelly’s poop. On four different occasions at the ISS, Kelly used cotton swabs to pick up poo particles. When the rockets arrived to drop off lab supplies, they returned to Earth with little tubes containing the swabs, which had to be frozen until all of the samples were collected. The process was tedious, and on one occasion, one of the SpaceX rockets exploded shortly after it launched in 2015.

The study also found that his telomeres, the caps at the ends of chromosomes, had lengthened in space, likely due to regular exercise and a proper diet, according to NASA. But when Kelly returned to Earth, they began to shorten and return to their pre-spaceflight length. Shorter telomeres have a correlation with aging and age-related diseases. “Although average telomere length, global gene expression, and microbiome changes returned to near preflight levels within six months after return to Earth, increased numbers of short telomeres were observed and expression of some genes was still disrupted,” researchers wrote.

Researchers say more studies will be needed before they send the first human to Mars. Check out NASA's video below to learn more about what they discovered.

[h/t PBS]

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