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"Neanderthal Boy," Michael McCullough, Flickr // CC BY-NC-ND 2.0
"Neanderthal Boy," Michael McCullough, Flickr // CC BY-NC-ND 2.0

Humans and Neanderthals Interbred 40,000 Years Earlier Than We Thought

"Neanderthal Boy," Michael McCullough, Flickr // CC BY-NC-ND 2.0
"Neanderthal Boy," Michael McCullough, Flickr // CC BY-NC-ND 2.0

We've known for a while that some Neanderthals and early modern humans mated; most of us still carry a small percentage of Neanderthal DNA (which may have some ill effects on us). But when exactly did that mating take place? An article, published in the journal Nature, suggests that interbreeding between humans and Neanderthals began 100,000 years ago. This extends the previously accepted timeline by 40,000 years, the BBC reports.

For the study, the scientists used the genome of a female Neanderthal who was discovered in a remote cave in the mountains of Siberia. While Neanderthal DNA found in modern humans supports the idea that the two groups met during migration out of Africa between 47,000 and 65,000 years ago, the presence of human DNA in the Neanderthal woman adds an earlier encounter to the narrative. That evidence may change what we knew about when migration out of Africa started and where early modern humans went.

"We conclude that in addition to later interbreeding events, the ancestors of Neanderthals from the Altai Mountains and early modern humans met and interbred, possibly in the Near East, many thousands of years earlier than previously thought," the scientists wrote.

Paleoanthropologist Chris Stringer of the Natural History Museum in London, who was not involved in the study, told the BBC that experts still aren't sure exactly where those interbreeding events took place. "We really don't know how widespread Neanderthals and early modern humans might have been in the regions between Arabia and China at this time," he said.

Stringer added that scientists are also unsure about the nature of the events or whether they were even consensual. One way to tell the difference would be to determine if human DNA was transferred solely from males to females or if there was a balance. Stringer says a lot more data is needed to determine that.

[h/t BBC]

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New Patient Test Could Suggest Whether Therapy or Meds Will Work Better for Anxiety
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Like many psychological disorders, there's no one-size-fits-all treatment for patients with anxiety. Some might benefit from taking antidepressants, which boost mood-affecting brain chemicals called neurotransmitters. Others might respond better to therapy, and particularly a form called cognitive behavioral therapy, or CBT.

Figuring out which form of treatment works best often requires months of trial and error. But experts may have developed a quick clinical test to expedite this process, suggests a new study published in the journal Neuropsychopharmacology.

Researchers at the University of Illinois at Chicago have noted that patients with higher levels of anxiety exhibit more electrical activity in their brains when they make a mistake. They call this phenomenon error-related negativity, or ERN, and measure it using electroencephalography (EEG), a test that records the brain's electric signals.

“People with anxiety disorders tend to show an exaggerated neural response to their own mistakes,” the paper’s lead author, UIC psychiatrist Stephanie Gorka, said in a news release. “This is a biological internal alarm that tells you that you've made a mistake and that you should modify your behavior to prevent making the same mistake again. It is useful in helping people adapt, but for those with anxiety, this alarm is much, much louder.”

Gorka and her colleagues wanted to know whether individual differences in ERN could predict treatment outcomes, so they recruited 60 adult volunteers with various types of anxiety disorders. Also involved was a control group of 26 participants with no history of psychological disorders.

Psychiatrists gauged subjects’ baseline ERN levels by having them wear an EEG cap while performing tricky computer tasks. Ultimately, they all made mistakes thanks to the game's challenging nature. Then, randomized subjects with anxiety disorders were instructed to take an SSRI antidepressant every day for three months, or receive weekly cognitive behavioral therapy for the same duration. (Cognitive behavioral therapy is a type of evidence-based talk therapy that forces patients to challenge maladaptive thoughts and develop coping mechanisms to modify their emotions and behavior.)

After three months, the study's patients took the same computer test while wearing EEG caps. Researchers found that those who'd exhibited higher ERN levels at the study's beginning had reduced anxiety levels if they'd been treated with CBT compared to those treated with medication. This might be because the structured form of therapy is all about changing behavior: Those with enhanced ERN might be more receptive to CBT than other patients, as they're already preoccupied with the way they act.

EEG equipment sounds high-tech, but it's relatively cheap and easy to access. Thanks to its availability, UIC psychiatrists think their anxiety test could easily be used in doctors’ offices to measure ERN before determining a course of treatment.

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Newly Discovered 350-Year-Old Graffiti Shows Sir Isaac Newton's Obsession With Motion Started Early
Hulton Archive//Getty Images
Hulton Archive//Getty Images

Long before he gained fame as a mathematician and scientist, Sir Isaac Newton was a young artist who lacked a proper canvas. Now, a 350-year-old sketch on a wall, discovered at Newton’s childhood home in England, is shedding new light on the budding genius and his early fascination with motion, according to Live Science.

While surveying Woolsthorpe Manor, the Lincolnshire home where Newton was born and conducted many of his most famous experiments, conservators discovered a tiny etching of a windmill next to a fireplace in the downstairs hall. It’s believed that Newton made the drawing as a boy, and may have been inspired by the building of a nearby mill.

A windmill sketch, believed to have been made by a young Sir Isaac Newton at his childhood home in Lincolnshire, England.
A windmill sketch, believed to have been made by a young Sir Isaac Newton at his childhood home in Lincolnshire, England.
National Trust

Newton was born at Woolsthorpe Manor in 1642, and he returned for two years after a bubonic plague outbreak forced Cambridge University, where he was studying mechanical philosophy, to close temporarily in 1665. It was in this rural setting that Newton conducted his prism experiments with white light, worked on his theory of “fluxions,” or calculus, and famously watched an apple fall from a tree, a singular moment that’s said to have led to his theory of gravity.

Paper was a scarce commodity in 17th century England, so Newton often sketched and scrawled notes on the manor’s walls and ceilings. While removing old wallpaper in the 1920s and '30s, tenants discovered several sketches that may have been made by the scientist. But the windmill sketch remained undetected for centuries, until conservators used a light imaging technique called Reflectance Transformation Imaging (RTI) to survey the manor’s walls.

Conservators using light technology to survey the walls of Woolsthorpe Manor,  the childhood home of Sir Isaac Newton.
A conservator uses light technology to survey the walls of Woolsthorpe Manor, the childhood home of Sir Isaac Newton.
National Trust

RTI uses various light conditions to highlight shapes and colors that aren’t immediately visible to the naked eye. “It’s amazing to be using light, which Newton understood better than anyone before him, to discover more about his time at Woolsthorpe,” conservator Chris Pickup said in a press release.

The windmill sketch suggests that young Newton “was fascinated by mechanical objects and the forces that made them work,” added Jim Grevatte, a program manager at Woolsthorpe Manor. “Paper was expensive, and the walls of the house would have been repainted regularly, so using them as a sketchpad as he explored the world around him would have made sense," he said.

The newly discovered graffiti might be one of many hidden sketches drawn by Newton, so conservators plan to use thermal imaging to detect miniscule variations in the thickness of wall plaster and paint. This technique could reveal even more mini-drawings.

[h/t Live Science]

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