istock
istock

Human Ancestors Made Tools 3.3 Million Years Ago

istock
istock

Flints, hammers, anvils, and more found on the western edge of Lake Turkana in Kenya indicate that human relatives have been making and using tools for even longer than we thought. Tool use dates back to 3.3 million years ago, according to a new study in the journal Nature, moving the timeline for when human ancestors began using tools back by 700,000 years. Previous estimates put the development of tools at approximately 2.6 million years ago.

Making and using tools has long been considered a key factor in higher cognition and intelligence, and prehistoric tools provide important insight into how humans evolved. While it’s unclear who made these tools, these artifacts are more than a half-million years older than the earliest fossils scientists have discovered of Homo, the genus that includes the human species and their immediate ancestors. 

Stony Brook University archaeologist Sonia Harmand with a prehistoric tool. Image Credit: MPK-WTAP

The stone tools excavated in Kenya are more primitive than the 2.6-million-year-old evidence of tools found in Ethiopia, but they still indicate that those early human ancestors had decent enough motor control to wield a stone hammer. Markings on the stones suggest that the stones were used to pound things, and some, called cores, were shaved to produce sharp flakes that could have been used for cutting plants or animal material. 

Tools aren’t just the purview of humankind. Several other animals use tools, including a few primates, dolphins, and crows. But unlike humans, they don’t make the tools themselves. While the ability to fashion complex tools has been important to the evolution and survival of the human species, this finding suggests that manufacturing tools was an important part of life even before the earliest humans appeared on the scene. 

A tool found at the excavation site in Kenya. Image Credit: MPK-WTAP

“We know now that at least one group of ancient hominin [humans and their close ancestors] started intentionally knapping stones to make tools long before previously thought,” says study author Sonia Harmand of Stony Brook University in New York. “They show that the knappers already had an understanding of how stones can be intentionally broken, 3.3 million years ago, beyond what the first hominin who accidentally hit two stones together and produced a sharp flake would have had.”

nextArticle.image_alt|e
iStock
Drought Reveals Ancient Sites in Scotland That Can Only Be Spotted From the Air
iStock
iStock

Typically rainy Scotland is in the middle of an unusually dry summer—and local archaeologists are taking advantage of it. As the BBC reports, the drought has revealed ancient sites, including Roman camps and Iron Age graves, that have been hidden by farm soil for years.

Historic Environment Scotland has been conducting aerial surveys of the country's landscape since the 1930s, but it's in seasons like this, when the crops recede during dry weather, that the buried remains of ancient structures are easiest to spot. Conditions this summer have been the best since 1976 for documenting archaeological sites from the sky.

Aerial view of field.
Historic Environment Scotland

The crescent-shaped crop mark in the photo above indicates a souterrain, or underground passageway, that was built in the Scottish Borders during the Iron Age. The surveyors also found remains of a Roman temporary camp, marked by straight lines in the landscape, built in modern-day Lyne—an area south of Edinburgh already known to have housed a complex of Roman camps and forts.

Aerial view of field.
Historic Environment Scotland

In the image below you'll see four small ditches—three circles and one square—that were likely used as burial sites during the Iron Age. When crops are planted over an ancient ditch, they have more water and nutrients to feed on, which helps them grow taller and greener. Such crops are especially visible during a drought when the surrounding vegetation is sparse and brown.

Aerial view of field.
Historic Environment Scotland

Historic Environment Scotland has a team of aerial surveyors trained to spot the clues: To date, they've discovered more than 9000 archaeological sites from the air. HSE plans to continue scoping out new areas of interest as long as the dry spell lasts.

It's not just in Scotland that long-hidden settlements are coming to light: similar aerial surveys in Wales are finding them too.

[h/t BBC]

nextArticle.image_alt|e
iStock
Billion-Year-Old Rocks Reveal the First Color Ever Produced by a Living Thing
iStock
iStock

Billions of years ago, before there were plants and animals on Earth, there were rocks, tiny organisms, water, and not much else. It’s hard to envision what our barren planet looked like back then, but scientists now have some idea of what colors dominated the landscape.

As Vice reports, a team of researchers from Australian National University (ANU) were able to pinpoint the oldest colors ever produced by a living creature: purple-red hues dating back more than 1.1 billion years. The pigments, which appear pink when diluted, were found in molecular fossils of chlorophyll that had been preserved in rocks beneath the Sahara desert. A billion years ago, though, this area was “an ancient ocean that has long since vanished,” Nur Gueneli of ANU said in a statement.

Chlorophyll may very well be green, but these pinkish pigments are a result of "fossilized porphyrins, a type of organic compound that forms an atomic ring around a magnesium ion to form a chlorophyll molecule," Vice explains.

While this provides an interesting visual, the color itself is less important than what it reveals about some of the earliest life forms on Earth. Scientists determined that the chlorophyll was produced by ancient organisms called cyanobacteria, which derived energy via photosynthesis and ruled the oceans at that time, researchers wrote in a paper published in the Proceedings of the National Academy of Sciences. Larger planktonic algae—a potential food source for bigger life forms— were scarce, which may explain why large organisms didn’t roam the Earth a billion years ago. That kind of algae was about a thousand times larger than the cyanobacteria.

“The cyanobacterial oceans started to vanish about 650 million years ago, when algae began to rapidly spread to provide the burst of energy needed for the evolution of complex ecosystems, where large animals, including humans, could thrive on Earth," ANU associate professor Jochen Brocks said.

So the next time you encounter algae, you can thank it for helping you secure a spot on this planet.

[h/t Vice]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios