An 88,000-Year-Old Middle Finger May Change What We Know About Human Migration

Ian Cartwright
Ian Cartwright

A middle finger might change what we thought we knew about human migration from Africa. As Gizmodo reports, a new study in Nature Ecology and Evolution analyzes what may be the oldest modern human fossil outside of Africa and the Levant (modern-day Israel, Lebanon, Syria, and Jordan). Found in an ancient lake bed in the Arabian desert, the bone has been dated to 88,000 years ago, indicating that human migration from Africa may have started much earlier than previously thought.

Previous research has suggested that Homo sapiens populations migrated out of Africa and into Eurasia (perhaps thanks to climate change) in one big wave around 60,000 years ago. The fossilized finger bone, about an inch long, indicates the story might be more complicated.

A paleontologist with the Saudi Geological Survey, Iyad Zalmout, found the bone in 2016. He and his fellow researchers created 3D scans of the bone and compared them with other finger bones from Homo sapiens, Neanderthals, and modern primates like gorillas to determine that it is, in fact, a human bone. They then dated the fossil using uranium series dating, a measure of the bone's ratio of radioactive elements, to arrive at an estimated age of roughly 88,000 years old. They also found animal fossils and sediment at the site to be around 90,000 years old.

A surveyor stands in the desert.
The area in Saudi Arabia where the finger was found.
Klint Janulis

At that time, the area in the Nefud Desert where the bone was found would have been semi-arid grasslands surrounding a freshwater lake, a more hospitable climate than it is today. At some parts during this era, the Red Sea between Africa and the Arabian Peninsula would have been low enough to make it essentially just a big river, so humans could have crossed there, as a related article in the journal by anthropologist Donald Henry notes.

Several scientists told Gizmodo that it's possible that the bone isn't human at all—it could belong to a relative of Homo sapiens—and that the authors of the new study are overstating the significance of their finding, so the analysis is somewhat controversial.

However, other evidence has pointed to an earlier African exit date for humans. In 2015, scientists in China discovered human teeth they dated to 80,000 years ago, though they weren't able to date the bone directly—instead, they analyzed the teeth's surroundings. In January 2018, scientists announced that they had found a partial jawbone in an Israeli cave dating back at least 177,000 years.

"The ability of these early people to widely colonize this region [of Arabia] casts doubt on long held views that early dispersals out of Africa were localized and unsuccessful," said lead author Huw Groucutt, of the University of Oxford and the Max Planck Institute for the Science of Human History, in a statement.

[h/t Gizmodo]

Scientists Find Fossil of 150-Million-Year-Old Flesh-Eating Fish—Plus a Few of Its Prey

M. Ebert and T. Nohl
M. Ebert and T. Nohl

A fossil of an unusual piranha-like fish from the Late Jurassic period has been unearthed by scientists in southern Germany, Australian news outlet the ABC reports. Even more remarkable than the fossil’s age—150 million years old—is the fact that the limestone deposit also contains some of the fish’s victims.

Fish with chunks missing from their fins were found near the predator fish, which has been named Piranhamesodon pinnatomus. Aside from the predator’s razor-sharp teeth, though, it doesn’t look like your usual flesh-eating fish. It belonged to an extinct order of bony fish that lived at the time of the dinosaurs, and until now, scientists didn’t realize there was a species of bony fish that tore into its prey in such a way. This makes it the first flesh-eating bony fish on record, long predating the piranha. 

“Fish as we know them, bony fishes, just did not bite flesh of other fishes at that time,” Dr. Martina Kölbl-Ebert, the paleontologist who found the fish with her husband, Martin Ebert, said in a statement. “Sharks have been able to bite out chunks of flesh, but throughout history bony fishes have either fed on invertebrates or largely swallowed their prey whole. Biting chunks of flesh or fins was something that came much later."

Kölbl-Ebert, the director of the Jura Museum in Eichstätt, Germany, says she was stunned to see the bony fish’s sharp teeth, comparing it to “finding a sheep with a snarl like a wolf.” This cunning disguise made the fish a fearful predator, and scientists believe the fish may have “exploited aggressive mimicry” to ambush unsuspecting fish.

The fossil was discovered in 2016 in southern Germany, but the find has only recently been described in the journal Current Biology. It was found at a quarry where other fossils, like those of the Archaeopteryx dinosaur, have been unearthed in the past.

[h/t the ABC]

Advanced CT Scans Reveal Blood Vessels and Skin Layers in a Mummy's Hand

Jenny Romell, et al./Radiology
Jenny Romell, et al./Radiology

Mummies hold some intriguing secrets to their pasts, like the food they ate and the diseases they had when they were alive. Now scientists are using a tool originally designed for medicine to get an even deeper look at the clues mummified bodies carry with them into the present day, Gizmodo reports.

In a proof-of-concept study published in the journal Radiology, researchers from the KTH Royal Institute of Technology in Sweden detail how a new-and-improved CT scanning technique can be used to visualize the interior of mummies on a microscopic level. By creating detailed X-ray images, CT scans allow doctors to see inside their patients without invasive surgery. Archaeologists have been using this technology to study delicate ancient artifacts for years, but the level of detail that can be achieved this way—especially when it comes to looking at interior soft tissue—is limited.

The upgraded version of the tech, called phase-contrast CT scanning, measures the phase shift, or the change in the position of a light wave, that occurs when X-rays pass through solid objects. The images generated this way have a higher contrast level than conventional X-rays, which means they capture more detail.

Cross-section of mummy hand.
Jenny Romell, et al./Radiology

Doctors have been using this 10-year-old technology to examine soft tissues like organs and veins in living patients, but it hadn't been used on a mummy until recently. Working with a mummified human right hand dating back to 400 BCE in Egypt, which they borrowed from the Museum of Mediterranean and Near Eastern Antiquities in Stockholm, the researchers fired up a phase-contrast CT scanner. It produced images with a resolution of 6 to 9 microns, giving a clear picture of the different layers of skin, individual cells in the connective tissue, and the blood vessels in the nail bed—all without damaging the artifact. Previously, researchers looking to study these same tissues in mummies would have needed to use a scalpel.

As Ars Technica reports, a phase-contrast CT scanner is similar in cost to the conventional machine. The study authors hope their work will lead to phase-contrast CT scanning becoming just as common in archaeology as regular CT scanning, potentially creating new research opportunities in mummies that will be discovered in the future and even in artifacts that have already been examined.

[h/t Gizmodo]

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