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]

Homo Erectus Might Have Been Really Lazy

Shipton et. al,
Shipton et. al, PLOS ONE (2018)

Of all the human species that once roamed the world, only one remains—us. Why did our primitive cousins go extinct? For Homo erectus, something like laziness may have played a role, Cosmos reports.

A new study in the journal PLOS ONE explores the role that H. erectus's lack of drive may have contributed to its extinction. The international team of researchers based their analysis on an excavation of a paleolithic site in central Saudi Arabia, finding that the tools H. erectus made were of consistently lower quality than what tool makers in later periods used. Their tools were constructed with whatever material was easiest to get, rather than what would make the best tools.

And it wasn’t because better materials weren’t available. "At the site we looked at, there was a big rocky outcrop of quality stone just a short distance away up a small hill,” study co-author Ceri Shipton of the Australian National University said in a press release. “But rather than walk up the hill, they would just use whatever bits had rolled down and were lying at the bottom.” He added, “They knew it was there, but because they had enough adequate resources, they seem to have thought, ‘why bother?’”

A row of stone tools excavated from Saffaqah
Some of the stone tools
Shipton et. al, PLOS ONE, (2018)

Meanwhile, other hominin species, like our own Homo sapiens, were happily clambering up mountains to seek out better materials for their tools. Shipton suggests that H. erectus lacked the tendency toward exploration and curiosity that has helped our species thrive.

This “laziness,” combined with changes to their environment, was likely what did in H. erectus. As the humid environment around them became drier, H. erectus seemingly didn’t adapt: They didn't invent new kinds of tools to deal with the changing landscape, nor did they relocate or travel farther afield. The research team found the tools largely near dry river beds, suggesting that H. erectus neither progressed technologically nor modified their behavior for their altered habitat.

H. erectus did manage to walk upright as we do—a first in human evolution—and it was likely the first hominin to expand their habitat beyond Africa. But the combination of these two newly identified shortcomings may have contributed to H. erectus's demise.

[h/t Cosmos]

Intriguing New Theory Might Explain the Fate of Easter Island's Civilization

iStock
iStock

Standing up to 33 feet high and weighing 81 tons, the huge moai statues of Easter Island (Rapa Nui) are the most recognizable artifacts of a thriving civilization that peaked at the middle of the last millennium. For hundreds of years, Polynesian peoples lived on the small island 2300 miles west of Chile and developed a complex culture. By the 1700s, when Europeans first arrived, much of the society was decimated.

For years, scientists thought they knew why—but fresh archaeological evidence has provided an alternative theory.

The Journal of Pacific Archaeology published a paper [PDF] this week contradicting the commonly held belief that, in the 1600s, Rapa Nui's inhabitants descended into a Lord of the Flies–like era of infighting and violence as a result of dwindling resources. According to new research, the island’s population may not have devolved into barbarism. Instead, they were collaborating on toolmaking.

University of Queensland archaeologist Dale Simpson, Jr. theorized that the raw materials used in the carving tools would reveal clues about the dynamics of the community. He and his colleagues collected 17 tools found near the moai, including axe-like toki. Using a mass spectrometer to analyze the chemical composition of the tools and samples from stone quarries on the island, Simpson and his colleagues found that most of the toki came from a single quarry.

Simpson believes this is evidence that Rapa Nui's people had not fallen into violent conflict, but were instead sharing resources—or at least allowing one another access to a favorite quarry for tool production. If the islanders were split into factions, it’s unlikely that whoever was controlling the quarry would permit rivals to make use of it.

If accurate, it would join other recent theories that are drawing a revised picture of Rapa Nui's civilization. Explorers once described a surplus of spear-like objects presumably used for combat, but modern researchers examining the tools (called mata’a) in 2015 found that their surfaces were too blunt to pierce skin and were probably used for tilling soil.

While Simpson's take on the newly discovered carving tools is an intriguing theory, researchers aren't ready to rewrite history just yet. Other scholars, including study co-author Jo Anne Van Tilburg, point out that raw materials for the tools could have been seized by force or some form of coercion.

More research will be needed to see if Simpson’s new theory holds up. If it does, it would present a new wrinkle in the storied history of Rapa Nui.

[h/t Gizmodo]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios