Tag Archives: skulls

Neanderthal-Shaped Skulls Could Shed Light on Why Some Individuals Experience Headaches

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3D Models of Skulls from Modern Humans and Neanderthals

Courtesy of Kimberly Anne Plomp

Abnormalities in the skull that compress the lower brain can lead to headaches and various neurological issues, potentially passed down from Neanderthals.

Individuals with Chiari malformations possess a smaller, flatter skull base near the spine junction, causing the cerebellum to be pressed into the neck’s spinal canal.

Type 1 Chiari malformations, which are the least severe, may impact about 1 in 100 individuals. Symptoms can include headaches, neck pain, sleep apnea, and numbness, although some may remain asymptomatic.

Approximately 15 years ago, Yvens Barbosa Fernandes, a neurosurgeon at Campinas State University in Brazil, observed that the skull base of his Chiari patients bore resemblance to Neanderthal specimens from the European Museum, particularly the gentle slopes of the occipital bone where the cerebellum rests. Neanderthals had larger brains than modern humans, yet their skulls were more oblique at the foreheads and bases, resulting in a flatter shape compared to the rounder modern human skulls.

In 2013, Barbosa Fernandes published his hypothesis, suggesting that the shape of Chiari skulls could have a genetic link to an extinct human species, Homo sapiens. “In Chiari’s case, I began to consider a lost connection between anthropology and medicine,” he stated.

Motivated by this theory, Kimberly Plomp from the University of the Philippines in Quezon City and her team created digital 3D models of 46 Chiari 1 skulls and 57 unaffected skulls using CT scans. Their comprehensive mathematical analysis confirmed that the Chiari-affected skulls exhibited more cerebral compression at a flat angle at the base where the cerebellum is located.

Subsequently, the group compared these recent skulls with digital models of eight fossilized heads from Homo Neanderthalensis, Homo Erectus, Homo Heidelbergensis, and ancient Homo sapiens.

They discovered that the skull base measurements of Neanderthal heads closely matched those of modern humans with Chiari, while the skull bases of all other ancient species resembled typical modern humans without Chiari. “This underscores the notion that these modern humans may share Neanderthal characteristics,” suggesting another way Neanderthal genes could influence our health.

For Barbosa Fernandes, this research offers solid backing for his hypothesis. “It makes sense; a less pronounced angle results in less space for the modern human brain,” he noted. “Until now, I lacked scientific evidence to support my theory. This research brings me significantly closer to that proof.”

Looking ahead, the team intends to analyze the DNA of individuals with Chiari malformations in search of Neanderthal genetic markers, according to Plomp.

Other Chiari malformations (types 2-4) are believed to stem from various causes. Type 2 is associated with severe forms of spina bifida, while types 3 and 4 are exceedingly rare and can pose life-threatening risks.

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Source: www.newscientist.com

The specialized adaptation of fox skulls for diving into snow

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Red fox diving into the snow to catch prey

Maxime Riendau/Getty Images

Some foxes can dive headfirst into snow without causing harm, and we now know how the shape of their skulls is adapted to this technique.

In colder climates, where small rodents live deep beneath the snow, red foxes (Vulpes Vulpes Vulpes) and arctic fox (Vulpes lagopus) has a special hunting technique known as mouse. They use their strong sense of hearing to pinpoint the location of their prey, then jump into the air and dive face-first into large piles of snow at speeds of up to 4 meters per second, catching their prey by surprise.

“This is a very interesting and unique behavior,” he says. Jung Sung-hwan At Cornell University in New York. “Not all foxes do that.”

To learn more about why red and arctic foxes are so adept at snow diving, Jung et al. scanned.

Their analysis found that felines tend to have broader and shorter snouts compared to foxes. This creates a stronger bite, which is more beneficial for felines, which typically hunt alone, Jung said.

Foxes, on the other hand, which hunt in packs, had much longer and more pointed skulls. This leads to a weak bite. The red fox and the arctic fox have similarly narrow muzzles that are slightly longer than other foxes.

The researchers dropped a 3D-printed model of a regular arctic fox skull and a flattened version of the skull into snow from a height of 50 centimeters.

“What we found is that a sharper nose compresses the snow less, reducing the impact,” Jung says. This reduces the risk of injury. Its longer, pointier snout gently pushes the snow aside, as if it were liquid, he said. “Such an elongated shape helps foxes dive safely into the snow so they can focus on hunting.”

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Source: www.newscientist.com