Early humans adapted to extreme habitats. Researchers say it set the stage for global migration
Humans are the only animal that lives in virtually every possible environment, from rainforests to deserts to tundra.
This adaptability is a skill that long predates the modern age. According to a new study published Wednesday in Nature, ancient Homo sapiens developed the flexibility to survive by finding food and other resources in a wide variety of difficult habitats before they dispersed from Africa about 50,000 years ago.
'Our superpower is that we are ecosystem generalists,' said Eleanor Scerri, an evolutionary archaeologist at the Max Planck Institute of Geoanthropology in Jena, Germany.
Our species first evolved in Africa around 300,000 years ago. While prior fossil finds show some groups made early forays outside the continent, lasting human settlements in other parts of the world didn't happen until a series of migrations around 50,000 years ago.
'What was different about the circumstance of the migrations that succeeded — why were humans ready this time?' said study co-author Emily Hallett, an archaeologist at Loyola University Chicago.
Earlier theories held that Stone Age humans might have made a single important technological advance or developed a new way of sharing information, but researchers haven't found evidence to back that up.
This study took a different approach by looking at the trait of flexibility itself.
The scientists assembled a database of archaeological sites showing human presence across Africa from 120,000 to 14,000 years ago. For each site, researchers modeled what the local climate would have been like during the time periods that ancient humans lived there.
'There was a really sharp change in the range of habitats that humans were using starting around 70,000 years ago,' Hallet said. 'We saw a really clear signal that humans were living in more challenging and more extreme environments.'
While humans had long survived in savanna and forests, they shifted into everything from from dense rainforests to arid deserts in the period leading up to 50,000 years ago, developing what Hallet called an "ecological flexibility that let them succeed.'
While this leap in abilities is impressive, it's important not to assume that only Homo sapiens did it, said University of Bordeaux archaeologist William Banks, who was not involved in the research.
Other groups of early human ancestors also left Africa and established long-term settlements elsewhere, including those that evolved into Europe's Neanderthals, he said.
The new research helps explain why humans were ready to expand across the world way back when, he said, but it doesn't answer the lasting question of why only our species remains today.
___
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Science and Educational Media Group and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
The Guardian
11 hours ago
- The Guardian
Why Dr Paris uses her bare arms in the fight against Australia's mosquito-borne diseases
Dr Véronique Paris has a very hands-on approach to her research. She slides her bare arm inside a special cage and lets hundreds of mosquitoes bite her – all in the name of science. 'For most of the ones I feed, I just feel a little sensation,' the University of Melbourne medical entomologist says. 'Some species do have a bit more of a mechanical feel to them.' Sign up for Guardian Australia's breaking news email She describes the buzzing cage of mosquitoes as her 'colony', and 'to make sure they stay healthy' Paris feeds them her blood about once a week. 'If I am running an experiment or want to collect more eggs for upcoming work, this can increase to about four times a week.' Her research is focused on reducing the transmission of mosquito-borne diseases to humans, such as the flesh-eating Buruli ulcer – that if untreated can cause disfiguration and tissue loss. Paris enjoys sharing her work – and methods – with her community of 13,000 followers on Instagram. The 35-year-old says she moved to Instagram and away from professional social media platforms such as LinkedIn, or even Bluesky, to 'reach people that are not necessarily already looking for scientific content'. '[It] has been very rewarding and there are lots of people that ask lots of questions,' she says. Paris's interest in mosquito research began when she started her PhD at the University of Melbourne, after moving to Australia from Germany. 'I wanted to do something for the local community and understand local mosquitoes [and] locally transmitted diseases like Ross River virus and Buruli ulcer.' Cases of Buruli ulcer have risen sharply in recent years, from 135 in 2020 to 238 in late 2023, according to the Victorian Department of Health. The disease, which is spreading across Victoria, is also found in far north Queensland and the Northern Territory. While possums have long been suspected to play a role in the spread of Buruli ulcer, a 2024 study provided the first strong evidence linking mosquitoes to its transmission. Paris and other researchers are trying to find out how exactly mosquitoes acquire and transmit the pathogen to humans. Sign up to Breaking News Australia Get the most important news as it breaks after newsletter promotion Paris said she was shocked when she first saw her scientific colleagues feeding the insects their blood. 'I was planning big experiments and wanting to have my own mosquito colony, so I felt like I wanted to try it at least once to see if that is something that I can do.' Now it's a part of her weekly lab routine. 'My body has certainly adapted to it … I can feed a cage of mosquitoes and then it's itchy right after, and then I need to be good about not scratching, so I distract myself for about an hour.' Researchers feeding their own colonies is not compulsory, Paris says. 'There will always be volunteers around that can do that, so no one has to feed mosquitoes if they don't want to and that's totally fine.' But outside the lab, getting involuntarily bitten by mosquitoes is a completely different story. Paris says if a mosquito bites her on the ankle while she's in the garden, it might itch for days. Each bite is different, depending on the location on her body and the species of mosquito doing the biting, she says. There are about 300 species of mosquitoes in Australia, how much they itch depends on the person they bite, she explains, adding that the bump and itch is caused by someone's immune response to the bite, so it very person specific. Her top tip? Don't scratch the bite as it only makes the itching worse.
BBC News
2 days ago
- BBC News
Rare ducklings hatch at Chester Zoo
A group of rare ducklings have hatched at Chester Maccoa duck is one of Africa's rarest and most endangered duck the first time the species has ever been successfully bred at the say only around 5,000 of the ducks remain in the wild, with the latest surveys finding just 14 individuals in Kenya and fewer than 100 in Tanzania - prompting concern over the future of the conservationists say they hope the successful hatching will lead to more protection for the birds. Maccoa ducks are diving ducks often found in nutrient-rich wetland habitats, like freshwater wetlands and are known for their stiff tails and deep-blue species is listed as endangered on the International Union for the Conservation of Nature's (IUCN) Red List of Threatened degradation, water pollution and climate change have been blamed for the species decline. There are just twelve zoos in the world that look after Maccoa ducks. Andrew Owen, Head of Birds at Chester Zoo, said:"This success gives a real boost to the future of the species... These birds are facing rapid decline in the wild, so every hatchling really does count."
Metro
2 days ago
- Metro
Human population nearly went extinct – with just 1,280 people left
Hiyah Zaidi Published June 20, 2025 12:50pm Link is copied Comments Humans have been around for a while, but we haven't always been an abundant species. In fact, ancient humanity was almost wiped out around 900,000 years ago and the global population dwindled to a mere 1,280 reproducing individuals, a study claims. And the researchers also claim that they stayed like this for 117,000 years. So, what is going on? (Picture: Getty) The study, which is published in the journal Science, reveals human ancestors in Africa almost faced extinction, and the research suggests there was a drastic reduction in the population of our ancestors well before our species, Homo sapiens, also known as modern humans, emerged. The information is based on a new computer model developed by a group of scientists based in China, Italy and the United States (Picture: Getty) The researchers used a statistical method and gathered genetic information from 3,154 present-day human genomes. They found that around 98.7% of human ancestors were lost. The researchers say that the population crash matches with a gap in the fossil record. They say this could have led to a new hominin species that was a common ancestor of modern humans, or Homo sapiens, and Neanderthals (Picture: Getty) Senior author Dr Yi-Hsuan Pan, an evolutionary and functional genomicist at East China Normal University, said: 'The novel finding opens a new field in human evolution because it evokes many questions, such as the places where these individuals lived, how they overcame the catastrophic climate changes, and whether natural selection during the bottleneck has accelerated the evolution of the human brain' (Picture: Getty) The exact cause is unknown, but it is thought that the near-extinction has been blamed on Africa's climate getting much colder and drier. Dr Pan said: 'The novel finding opens a new field in human evolution by raising many new questions. 'Where did these individuals live? How did they overcome catastrophic climate change? And did natural selection during the bottleneck affect their evolution? All this remains to be answered' (Picture: Getty) It's fine to say 900,000 years ago, but in what period of human evolution did this happen? The researchers say that the signature of this bottleneck can be seen in the genetics of people with non-African heritage. Therefore, it would have been hundreds of thousands of years before humans migrated outside of Africa. The researchers estimated that there would have been an effective population size of around 1,280 individuals between 930,000 and 813,000 years ago. But, this doesn't mean this was the entire population, only this number successfully bred and passed on their genes to the next generation (Picture: Getty) The bottleneck also coincided with dramatic changes in climate during what's known as the mid-Pleistocene transition. At this time, glacial periods became longer and more intense, leading to a drop in temperature and very dry climatic conditions. However, the researchers also suggested that the control of fire, as well as the climate shifting to be more hospitable for human life, may have led to a later rapid population increase around 813,000 years ago (Picture: Getty)
