Archaeologists Unearth 2.75 Million-Year-Old Stone Tools in Kenya

Archaeologists have unearthed Oldowan stone tools across three distinct archaeological layers at the Namorotuknan site, dated to roughly 300,000 years (2.75 million to 2.44 million years ago) within the Koobifora Formation in northeastern Turkana Basin, Marsabit District, Kenya. This discovery, indicating careful selection of rock materials, points to the sustained practice of toolmaking across epochs.

A 2.58 million year old stone tool excavated from the Namorotuknan ruins in Kenya. Image credit: Brown others., doi: 10.1038/s41467-025-64244-x.

The initial phases of toolmaking, which date back over 3 million years, emphasize percussion techniques that are prevalent in the human lineage and shared with other primates.

The practice of tool use associated with extractive foraging continues to be a notable aspect of certain modern primate species.

The earliest structured creation of sharp stone tools, referred to as Oldowan, has been documented at hominin sites in eastern Africa: Lady Gerar and Gona in the Afar Basin (2.6 million years ago), Ethiopia, and Nyayanga in western Kenya (2.6 to 2.9 million years ago).

Professor David R. Brown, an anthropologist at George Washington University and the Max Planck Institute for Evolutionary Anthropology, along with his team, discovered stone tools across three archaeological horizons at the Namorotuknan site, estimated to be 2.75 million years ago, 2.58 million years ago, and 2.44 million years ago.

“This site tells an extraordinary story of cultural continuity,” Professor Brown remarked.

“What we observe is a long-standing tradition of technology rather than a singular innovation.”

“Our findings imply that tool usage might have been a more widespread adaptation among our primate ancestors,” stated Dr. Susana Carvalho, science director at Gorongosa National Park in Mozambique.

“Namorotsukunan offers a unique perspective into a transforming world: flowing rivers, fierce fires, expanding arid regions, and resilient tools.”

Stone tools discovered at the Three Horizons site at the Namorotuknan site in Kenya. Image credit: Brown others., doi: 10.1038/s41467-025-64244-x.

“For 300,000 years, the same tools have endured, possibly revealing the origins of our fundamental habit of using technology to adapt to change,” remarked Dr. Dan V. Parc Laurier, a researcher at GeoEcoMar, Utrecht University, and the University of São Paulo.

“Early humans showed remarkable consistency in creating sharp stone tools, reflecting advanced technology and knowledge handed down through numerous generations.”

Researchers have utilized volcanic ash dating, ancient sediment magnetic signals, chemical signatures in rocks, and microscopic plant remains to construct a broad narrative of climate change, providing context for the influence of technology on human evolution.

These toolmakers managed to persevere through significant environmental transformations. Their innovative technology facilitated new dietary practices, including the consumption of meat, transforming challenges into survival advantages.

“These discoveries indicate that humans had already mastered the creation of sharp stone tools by approximately 2.75 million years ago, suggesting that the inception of Oldowan technology is older than previously believed,” stated Dr. Nigas Baraki, a researcher at George Washington University.

Dr. Francis Forrest, a researcher at Fairfield University, added: “At Namorotuknan, cut marks connect stone tools with carnivory, indicating a diverse diet that thrived amidst shifting landscapes.”

“The record of plant fossils narrates a fascinating tale: the landscape transitioned from rich wetlands to fire-prone arid grasslands and semi-deserts,” noted Dr. Rahab N. Kinyanjui, a researcher at the National Museum of Kenya and the Max Planck Institute for Geoanthropology.

“Despite changes in vegetation, the production of tools remained consistent. This reflects resilience.”

of result Posted in today’s diary nature communications.

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Dr. Brown others. 2025. Early Oldowan technology flourished during Pliocene environmental change in the Turkana Basin of Kenya. Nat Commun 16, 9401;doi: 10.1038/s41467-025-64244-x

Source: www.sci.news

Over 140 Facebook moderators in Kenya diagnosed with severe PTSD from digital media duties

Over 140 Facebook content moderators have been diagnosed with severe post-traumatic stress disorder as a result of being exposed to distressing social media content, including violent acts, suicides, child abuse, and terrorism.

Dr. Ian Kananya revealed that these moderators, based at a facility in Kenya contracted by social media companies, worked long hours and were diagnosed with PTSD, generalized anxiety disorder (GAD), and major depressive disorder (MDD) by the Head of Mental Health Services at Kenyatta National Hospital in Nairobi.

A lawsuit filed against Meta, Facebook’s parent company, and the outsourcing company Samasource Kenya, which employed moderators from across Africa, brought to light the distressing experiences faced by these employees.

Images and videos depicting disturbing content caused some moderators to have physical and emotional reactions such as fainting, vomiting, screaming, and leaving their workstations.

The lawsuit sheds light on the toll that moderating such content takes on individuals in regions where social media usage is on the rise, often in impoverished areas.

Many of the moderators in question turned to substance abuse, experienced relationship breakdowns, and felt disconnected from their families, due to the nature of their work.

Facebook and other tech giants use content moderators to enforce community standards and train AI systems to do the same, outsourcing this work to countries like Kenya.

A medical report submitted to the court depicted a bleak working environment where moderators were constantly exposed to distressing images in a cold, brightly lit setting.

The majority of the affected moderators suffered from PTSD, GAD, or MDD, with severe symptoms affecting a significant portion of them, even after leaving their roles.

MetaSource and Samasource declined to comment on the allegations due to the ongoing litigation.

Foxglove, a nonprofit supporting the lawsuit, highlighted the lifelong impact that this work has had on the mental health of the moderators.

The lawsuit aims to hold the companies accountable for the traumatic experiences endured by the moderators in the course of their duties.

Content moderation tasks, though often overlooked, can have significant long-term effects on the mental health of those involved, as seen in this case.

Meta stresses the importance of supporting its content moderators through counseling, training, on-site support, and access to healthcare, while implementing measures to reduce exposure to graphic material.

Source: www.theguardian.com

Two hominin species lived together in Kenya 1.5 million years ago

Paleoanthropologists have discovered 1.5 million-year-old footprints of two very different species of humans. homo erectus and Paranthropus boisei — at the same location near Lake Turkana in Kenya.

A 3D computerized model of the surface of an area near Lake Turkana in Kenya shows fossil footprints. Paranthropus boisei (vertical footprint) separate footprint homo erectus Form a vertical path. Image credit: Kevin Hatala / Chatham University.

Hominin is a term that describes a subdivision of the larger category known as Hominidae.

The hominid family includes all extinct and living organisms that are thought to belong to the human lineage that emerged after we separated from our great ape ancestors. This is thought to have happened about 6 to 7 million years ago.

Paleoanthropologists have long hypothesized that: homo erectus and Paranthropus boisei They coexisted.

According to the fossil record, homo erectus It lasted another million years.

Paranthropus boiseiHowever, they became extinct within a few hundred thousand years. Scientists don’t know why.

Both species had an upright posture and bipedal gait, and were very agile. We still know little about how these coexisting species interacted culturally and reproductively.

“Footprints are important because they fall into the category of trace fossils, which includes footprints, nests, and burrows,” said Craig Feibel, a professor at Rutgers University.

“Trace fossils are not parts of living things, but they provide evidence of behavior. Fossil body parts, such as bones and teeth, are evidence of past life, but they are easily displaced by water and predators. ”

This is a reconstruction by the artist homo erectus. Image credit: Yale University.

Professor Feibel and his colleagues discovered footprints from 1.5 million years ago. homo erectus and Paranthropus boisei Near Lake Turkana in Kenya.

“By being on the same surface and forming closely together over time, these two species are located at the edge of the lake and use the same habitat,” Professor Feibel said.

“Skeletal fossils have long provided the primary evidence for studying human evolution, but new data from fossil footprints reveals fascinating details about the evolution of human anatomy and locomotion. , giving further clues about ancient human behavior and the environment,” said Dr. Kevin Hatala. , a researcher at Chatham University.

“Fossil footprints are interesting because they provide a vivid snapshot of our fossil relatives coming to life.”

“These types of data can help us understand how living individuals millions of years ago moved through their environments, interacted with each other, and potentially interacted with other animals. Masu.”

“That's something you can never get from bones or stone tools.”

Paranthropus boisei. Image credit: © Roman Yevseyev.

The authors used a new method they recently developed that allows them to perform 3D analysis to distinguish one footprint from another.

“Biological anthropology is always interested in finding new ways to extract behavior from the fossil record, and this is a great example,” said Dr. Rebecca Ferrell, program director at the National Science Foundation.

“The team used state-of-the-art 3D imaging technology to create a completely new way to observe footprints, which will help us understand human evolution and the role of cooperation and competition in shaping our evolutionary journey. It will help.”

of findings Published in today's diary science.

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Kevin G. Hatala others. 2024. Footprint evidence of locomotor diversity and common habitats in early Pleistocene hominids. science 386 (6725): 1004-1010;doi: 10.1126/science.ado5275

Source: www.sci.news