Scientists May Have Finally Figured Out Why We Have Eyebrows

A Neanderthal skull
A Neanderthal skull
Stephane De Sakutin, AFP/Getty Images

If you look at a pictures of some of the earlier branches of humanity's family tree, like Neanderthals or Homo erectus, you might notice that Homo sapiens got off relatively lightly, eyebrow-wise. Most early hominins had thick, bony brow ridges rather than the smooth brows of modern humans. For years, researchers have been arguing over why those thick ridges existed—and why modern humans evolved tinier brows. A new study suggests that heavy brow ridges had social usefulness that was more important than their physiological function.

Previous research has suggested that thick brow ridges helped connect early hominins' eye sockets with their brain cavities, or protected the skull from the physical stress put on it by chewing jaws, or even helped early hominins take punches to the face.

The new study by University of York researchers, published in the journal Nature Ecology & Evolution, used a digital model of a fossil skull, thought to be between 125,000 and 300,000 years old, of an extinct species called Homo heidelbergensis that evolved sometime between 300,000 and 600,000 years ago in what is now Zambia. The researchers manipulated the model, changing the size of the brow ridge and seeing what happened when they applied different bite pressures. They found that the brow ridge was much bigger than it needed to be if its purpose was just to connect the eye sockets with the brain case, and that it didn't seem to protect the skull from the force of biting.

Instead, the researchers suggest that the brow ridge played a social role. Other primates have similar brow ridges that serve a social purpose rather than a mechanical one, like male mandrills, whose colorful, heavy-browed muzzles serve as dominance displays. Heavy brow ridges may have played a similar role in early human species.

As Homo sapiens evolved, more subtle communication may have taken precedence over the permanent social signal of a giant brow ridge. As foreheads became more vertical, eyebrows could move more freely and subtly, leading to important social signals in modern humans, like expressions of surprise or indignation.

An accompanying analysis in the same journal, by Spanish paleontologist Markus Bastir, cautions that the results of the new study are appealing, but should be taken with a grain of salt. The specimen used for the digital model was missing a mandible, and the researchers subbed in a mandible from a Neanderthal, a related species but still a distinct one from Homo heidelbergensis. This may have altered the analysis of the model and bite stresses. Still, the study provides "exciting prospects for future research," he writes.

People Have Been Dining on Caviar Since the Stone Age

iStock.com/Lisovskaya
iStock.com/Lisovskaya

Millennia before caviar became a staple hors d'oeuvre at posh parties, it was eaten from clay pots by Stone Age humans. That's the takeaway of a new study published in the journal PLOS One. As Smithsonian reports, traces of cooked fish roe recovered from an archeological site in Germany show just how far back the history of the dish goes.

For the study, researchers from Germany conducted a protein analysis of charred food remains caked to the shards of an Stone Age clay cooking vessel. After isolating roughly 300 proteins and comparing them to that of boiled fresh fish roe and tissue, they were able to the identify the food scraps as carp roe, or eggs. The scientists write that the 4000 BCE-era hunter-gatherers likely cooked the fish roe in a pot of water or fish broth heated by embers, and covered the pot with leaves to contain the heat or add additional flavor.

The clay shards were recovered from Friesack 4 in Brandenburg, Germany, a Stone Age archaeological site that has revealed about 150,000 artifacts, including items crafted from antlers, wood, and bone, since it was discovered in the 1930s. In the same study, the researchers report that they also found remnants of bone-in pork on a vessel recovered from the same site.

Other archaeological digs have shown that some of the foods we think of as modern delicacies have been around for thousands of years, including cheese, salad dressing, and bone broth. The same goes for beverages: Recently a 13,000-year-old brewery was uncovered in the Middle East.

[h/t Smithsonian]

Dozens of Cat Mummies, Plus 100 Cat Statues, Discovered in 4500-Year-Old Egyptian Tomb

iStock.com/Murat İnan
iStock.com/Murat İnan

The mummification of cats was a common practice in ancient Egypt, but it’s always a pleasant surprise when the felines are found thousands of years later. As NPR reports, dozens of mummified cats and 100 wooden cat statues were recently discovered in a 4500-year-old tomb near Cairo.

These items were uncovered by Egyptian archaeologists while excavating a newly discovered tomb in Saqqara, whose necropolis served the ancient city of Memphis. Another nearby tomb remains sealed, and it’s possible that it may have evaded looters and remained untouched for millennia.

In addition to the wooden statues, one bronze cat statue was found. It was dedicated to Bastet, goddess of cats, who was said to be the daughter of Re, god of the Sun. While cats were revered by ancient Egyptians, they weren’t directly worshipped. Rather, gods like Bastet were often depicted with the physical characteristics of an animal that was considered divine.

Even rarer than the mummified cats were a couple collections of mummified scarab beetles that were found in the tomb—the first of their kind to be unearthed in this particular necropolis, Egypt's Ministry of Antiquities announced in a Facebook post. The scarabs were still in “very good condition” because they had been wrapped in linen and placed inside two limestone sarcophagi, whose lids had black scarabs painted on top.

"The (mummified) scarab is something really unique. It is something really a bit rare," Mostafa Waziri, secretary general of Egypt's Supreme Council of Antiquities, told Reuters and other media. "A couple of days ago, when we discovered those coffins, they were sealed coffins with drawings of scarabs. I never heard about them before."

The beetles were an important religious symbol in ancient Egypt, representing renewal and rebirth. The Ministry of Antiquities said archaeologists also found wooden statues of a lion, a cow, and a falcon, as well as painted wooden sarcophagi of cobras (with mummies inside) and wooden sarcophagi of crocodiles.

[h/t NPR]

SECTIONS

arrow
LIVE SMARTER