All posts tagged: human evolution

New research finds early humans first used fire over one million years ago

New research finds early humans first used fire over one million years ago

Published by Jenni Sidey

Fire leaves behind a simple story when it is fresh. Ash settles, bones blacken, wood chars. Over a million years later, that story becomes much harder to read. In South Africa’s Wonderwerk Cave, researchers now say some of the oldest traces of fire linked to early humans reach back between 1.07 and 1.79 million years. That pushes the timeline deeper into the Early Acheulean and strengthens the case that hominins were not merely encountering wildfire on the landscape. They were likely bringing it into the cave and sustaining it there. The new evidence comes from Wonderwerk Cave in the Kalahari Desert, a site that has already played a central role in debates over early fire use. Earlier work there had identified strong evidence of burning around 1 million years ago. The latest study, published in PLOS One, extends that chronology with signs of repeated burning in older deposits. At the center of the new work is a method that picks up traces of intense heat in fossil bone by using light. The Wonderwerk Cave. (CREDIT: …

Humans nearly went extinct 930,000 years ago, researchers find

Humans nearly went extinct 930,000 years ago, researchers find

Published by Jenni Sidey

For more than a century, human origins have been told as a story of expansion, migration, and survival. But deep in that story sits a long, quiet stretch when almost nothing seems to happen. Fossils thin out. The trail goes cold. Then our lineage reappears. A new genetic analysis argues that this silence was anything but uneventful. Between about 930,000 and 813,000 years ago, the ancestral population that eventually gave rise to modern humans appears to have fallen to an average of roughly 1,280 breeding individuals. According to a new study, published in the journal Science, that collapse lasted about 117,000 years. Moreover, it wiped out nearly 98.7 percent of the ancestral population at the start of the bottleneck. It also erased about 65.85 percent of the genetic diversity seen in the lineage before it. That number is startling on its own. It is even more striking when set against the fossil record. Human remains in Africa and Eurasia become unusually scarce between roughly 950,000 and 650,000 years ago during this interval. Schematic diagram of …

Alice Roberts: ‘We are fundamentally, at the end of the day, animals’

Alice Roberts: ‘We are fundamentally, at the end of the day, animals’

Published by skeptic

Physically, Homo sapiens is not that special in the animal world. But the species has discovered ways of finding food and beating the odds of survival in every habitat from jungle to Arctic wasteland. It has also come to obsess Alice Roberts, who started off in medicine, becoming a surgeon and an anatomist. She was captivated by the evolutionary story of the ape that walked and talked, and is now professor of public engagement in science at the University of Birmingham, UK. Her expertise spans anthropology, archaeology and palaeopathology. She also has a huge track record of TV shows, from Digging for Britain and The Lost Scrolls of Pompeii to Witches of Essex, and a growing pile of books. Roberts was editor-in-chief of the latest, Humans: The evolution of a species, which tells the story of human evolution with illustrations and contributions from an international team, including Michael Marshall, who quizzed her about her latest work.   Michael Marshall: What’s the big idea in this latest part of your journey into the human past? Alice …

Neandertal ancestry significantly affects our immune system today

Neandertal ancestry significantly affects our immune system today

Published by Jenni Sidey

The legacy of Neandertals in modern people has often been framed as a genetic gift for fighting infection. This time, the picture looks less flattering. A new analysis suggests some inherited archaic variants are tied to higher levels of common DNA viruses in people today. In particular, this is true for Epstein-Barr virus. This hints at a more complicated immune inheritance than earlier work suggested. That matters because viruses have long been among humanity’s most persistent enemies. Many DNA viruses do not simply infect and leave. In fact, they can linger for life, usually quietly. Their levels rise and fall depending on how well the immune system contains them. The new study focused on whether archaic human ancestry, mostly from Neandertals, helps explain some of that variation. In present-day non-African populations, roughly 2% of the genome traces back to Neandertals. In Oceania, an added 2% to 4% comes from Denisovan ancestry. Those inherited fragments have already been linked to many traits, including immune function. However, their role in DNA virus defense has remained largely unclear. …

Malaria may have shaped human evolution for thousands of years

Malaria may have shaped human evolution for thousands of years

Published by Jenni Sidey

Malaria may have shaped early human life across Africa far earlier than once thought, steering where people could safely live and when groups stayed apart. By tracing ancient mosquito habitats, researchers found an overlooked disease barrier running through humanity’s deep past. For decades, scientists believed climate was the main force guiding where early humans lived across Africa. Shifting rain patterns opened green corridors. Expanding deserts cut populations apart. Wet and dry cycles pushed groups into new landscapes or trapped them in isolated regions. But a new study suggests another powerful force may have quietly shaped human history for tens of thousands of years: malaria. Researchers from the Max Planck Institute of Geoanthropology, the University of Cambridge and several collaborating institutions found evidence that malaria likely influenced where ancient human groups could safely live between 74,000 and 5,000 years ago. Their findings suggest the disease helped separate populations across Africa long before agriculture emerged. The study paints a striking picture of early human life. Ancient people were not only adapting to changing climates and dangerous predators. …

Neanderthals practiced dental care 59,000 years ago

Neanderthals practiced dental care 59,000 years ago

Published by Jenni Sidey

A deep cavity in a single Neanderthal molar from Siberia looks less like random damage and more like a deliberate act of treatment, a finding that pushes invasive dental care far deeper into human history. The tooth, known as Chagyrskaya 64, came from Chagyrskaya Cave in Russia’s Altai region and dates to about 59,000 years ago. In a study published in PLOS One, Alisa Zubova of the Peter the Great Museum of Anthropology and Ethnography in St. Petersburg and colleagues argue that the tooth was not simply worn down by age, broken by chance, or altered after burial. Instead, they say, a Neanderthal appears to have drilled into a decayed molar to reach infected tissue and ease pain. That makes the specimen the oldest known evidence of successful dental treatment, and the first such case documented outside Homo sapiens. “We were intrigued by the unusual shape of the concavity on the tooth’s chewing surface,” Zubova said. “It differed from the normal morphology of the pulp chamber and did not match the typical pattern of carious …

The strange reason nearly all humans are right-handed

The strange reason nearly all humans are right-handed

Published by Jenni Sidey

Roughly nine out of 10 people favor their right hand, a pattern so common it can feel almost invisible. Yet in evolutionary terms, it is deeply strange. No other primate species comes close to showing such a strong, consistent population-wide bias. A new analysis suggests that this familiar human trait may have grown out of two of the biggest changes in our evolutionary history. These are standing upright and growing a larger brain. Researchers led by the University of Oxford examined handedness across 41 species of monkeys and apes. They drew on data from 2,025 individuals. Their results, published in PLOS Biology, suggest humans no longer look like an outlier once two factors are taken into account. These two factors are brain size and the relative length of the arms compared with the legs, a standard marker tied to bipedalism. That matters because human handedness has long resisted easy explanation. Scientists have spent years tracing its roots in genes, brain specialization and development. Hand preference seems to begin early, possibly even before birth, and it …

Red meat once helped human evolution but now carries serious risks

Red meat once helped human evolution but now carries serious risks

Published by Jenni Sidey

Red meat has long occupied a near-mythic place in the story of human evolution. It is often cast as the food that helped make us human, feeding bigger brains, stronger bodies, and more complex societies. But a sweeping new review in The Quarterly Review of Biology argues that the story no longer ends there. The same food source that may once have helped early humans survive is now tied to chronic disease, environmental damage, and a global food system whose scale looks nothing like anything in the human past. In the review, Juston Jaco, Kalyan Banda, Ajit Varki, and Pascal Gagneux from the University of California, San Diego pull together evidence from archaeology, anthropology, nutrition, epidemiology, and molecular biology. Their conclusion is not that meat was a mistake. It is that modern red meat consumption has drifted far from its original biological and ecological setting. “The nature, scale, and context of red meat consumption today differ drastically from those of our evolutionary past,” the authors write. As Homo sapiens increasingly relied on animal-derived foods—whether hunted …

Homo erectus and modern humans may have more in common than previously thought

Homo erectus and modern humans may have more in common than previously thought

Published by Jenni Sidey

A handful of ancient teeth from China are giving scientists an unusual look at one of the hardest chapters in human evolution to read. For decades, Homo erectus has stood at the center of that mystery. The species was the first known member of the human genus to leave Africa, spreading across huge stretches of Eurasia and lasting for nearly 2 million years. Yet even with its importance, researchers have had little molecular evidence to work with. Fossils of H. erectus are rare and culturally invaluable, which has made destructive testing a nonstarter in many cases. That impasse may now be starting to shift. A team led by Fu Qiaomei of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences recovered protein evidence from six H. erectus teeth using a minimally invasive acid-etching technique that left the teeth’s overall morphology intact. The work, published in Nature, points to a possible genetic connection between East Asian H. erectus, Denisovans, and some present-day human populations. It also offers a new way to study …

Ancient teeth hint at links between Denisovans and Homo erectus

Ancient teeth hint at links between Denisovans and Homo erectus

Published by skeptic

A tooth found in Sunjiadong, China, thought to belong to Homo erectus Qiaomei Fu, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences For the first time, researchers have obtained substantial amounts of preserved protein from fossils believed to belong to the ancient human species Homo erectus. While proteins have been recovered from H. erectus fossils before, this is the first time they have revealed meaningful information about the species. The proteins suggest that H. erectus interbred with another group of hominins in Asia, the Denisovans. H. erectus was one of the most long-lived and widespread hominin species. They appear in the fossil record 2 million years ago in Africa and reached Eurasia by 1.8 million years ago – as shown by fossils from Dmanisi, Georgia. Some of them went all the way to Java in what is now Indonesia, where they survived until as recently as 108,000 years ago. In 2020, researchers led by Frido Welker at the University of Copenhagen in Denmark obtained proteins from the dental enamel of one H. erectus …