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Denisovan DNA discovered in a Tibetan cave may be only 45,000 years old

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denisovan dna discovered in a tibetan cave may be only 45000 years old

DNA belonging to Denisovans – the ancient human ancestor – discovered in a Tibetan cave may be only 45,000 years old, scientists say. 

The ancient Denisovan mitochondrial DNA was recovered in sediments from Baishiya Karst Cave, a limestone cave at the northeast margin of the Tibetan Plateau, 3,280 meters above sea level. 

Samples indicate Denisovans occupied the high-altitude cave as early as 100,000 years ago, and possibly as recently as 45,000 years ago, as well as at a point in-between. 

If the DNA is indeed only 45,000 years old, the species would have lived alongside modern humans in northeast central Asia. 

Site of Baishiya Karst Cave, a Tibetan Buddhist sanctuary and a high-altitude paleoanthropological site for researchers

Site of Baishiya Karst Cave, a Tibetan Buddhist sanctuary and a high-altitude paleoanthropological site for researchers

Site of Baishiya Karst Cave, a Tibetan Buddhist sanctuary and a high-altitude paleoanthropological site for researchers

Denisovans, a group of extinct hominins that diverged from Neanderthals about 400,000 years ago, may have more widely inhabited northeast central Asia than scientists previously thought.  

Samples of sediments were analysed by an international team including Charles Perreault at Arizona State University.

‘When we started developing this project about 10 years ago, none of us expected Baishya Cave to be such a rich site,’ he said

‘We’ve barely scratched the surface – three small excavation units have yielded hundreds of stone tools, fauna and ancient DNA. There’s a lot that remains to be done.’ 

‘Future work in Baishiya Cave may give us a truly unique access to Denisovan behavior and solidifies the picture that is emerging, which is that Denisovans, like Neanderthals, were not mere offshoots of the human family tree.

‘They were part of a web of now-extinct populations that contributed to the current human gene pool and shaped the evolution of our species in ways that we are only beginning to understand.’

By examining the sediment of Baishiya Karst Cave located on a high plateau in Tibet, researchers identified ancient mitochondrial DNA from Denisovans, indicating their presence possibly 45,000 years ago

By examining the sediment of Baishiya Karst Cave located on a high plateau in Tibet, researchers identified ancient mitochondrial DNA from Denisovans, indicating their presence possibly 45,000 years ago

By examining the sediment of Baishiya Karst Cave located on a high plateau in Tibet, researchers identified ancient mitochondrial DNA from Denisovans, indicating their presence possibly 45,000 years ago

A mandible fossil (the ‘Xiahe mandible’) from the same cave, which was dated to 160,000, had been previously identified as Denisovan, based on a single amino acid position. 

This new study of the DNA dispels any doubt left that the Denisovans occupied the cave, according to the researchers. 

Evidence of archaic hominins this far above sea level is unusual due to the severity of the conditions at high altitude.  

Life on the plateau is harsh due to its thin air, and humans can develop altitude sickness anywhere above 2,500 meters above sea level. 

Presence of the DNA suggests the Denisovans may have evolved adaptations to high altitude, much like modern Tibetans. 

The dates of the sediments with mitochondrial DNA, along with the older 160,000-year-old Xiahe mandible, suggest that the Denisovans have been on the Plateau continuously for tens of thousands of years.

Pictured, the Xiahe mandible remains. The Denisovan jawbone was originally discovered in 1980 by a local monk

Pictured, the Xiahe mandible remains. The Denisovan jawbone was originally discovered in 1980 by a local monk

Pictured, the Xiahe mandible remains. The Denisovan jawbone was originally discovered in 1980 by a local monk

This would have been more than long enough for genetic adaptations to emerge in Denisovans to help them survive adverse effects of high altitude. 

This discovery in Baishiya Karst Cave is the first time Denisovan DNA has been recovered from a location that is outside Denisova Cave in Siberia, Russia. 

This Siberian cave was previously the single location in the world where a handful of DNA-bearing Denisovan fossil bones have been discovered. 

In 2010, a fingerbone belonging to a previously unknown hominin species was found buried in Denisova Cave in the Russian Altai Mountains. 

Evidence of this new species forced anthropologists to revise their model of human evolution outside of Africa. 

Scientists had thought that modern humans left Africa about 60,000 years ago and, as they colonized Western Eurasia, found a world empty of any other archaic hominin species.

But this assumption stemmed in part from the fact that the prehistory of Asia is poorly known compared to that of Africa and Europe. 

Researchers suspected that Denisovans were widespread in Asia, based on the widespread Denisovan genomic signal among present-day Asians. 

The new study has been published in the journal Science.                   

It is thought that the shared ancestors of Denisovans and Neanderthals, which are unknown in the fossil record, likely split from the ancestors of modern humans around 800,000 years ago

It is thought that the shared ancestors of Denisovans and Neanderthals, which are unknown in the fossil record, likely split from the ancestors of modern humans around 800,000 years ago

It is thought that the shared ancestors of Denisovans and Neanderthals, which are unknown in the fossil record, likely split from the ancestors of modern humans around 800,000 years ago

WHO WERE THE DENISOVANS?

The Denisovans are an extinct species of human that appear to have lived in Siberia and even down as far as southeast Asia.

Although remains of these mysterious early humans have only been discovered at one site – the Denisova Cave in the Altai Mountains in Siberia, DNA analysis has shown they were widespread.

DNA from these early humans has been found in the genomes of modern humans over a wide area of Asia, suggesting they once covered a vast range.

DNA analysis of a fragment of pinky finger bone in 2010, (pictured) which belonged to a young girl, revealed the Denisovans were a species related to, but different from, Neanderthals.

DNA analysis of a fragment of pinky finger bone in 2010, (pictured) which belonged to a young girl, revealed the Denisovans were a species related to, but different from, Neanderthals.

DNA analysis of a fragment of pinky finger bone in 2010, (pictured) which belonged to a young girl, revealed the Denisovans were a species related to, but different from, Neanderthals.

They are thought to have been a sister species of the Neanderthals, who lived in western Asia and Europe at around the same time.

The two species appear to have separated from a common ancestor around 200,000 years ago, while they split from the modern human Homo sapien lineage around 600,000 years ago. 

Bone and ivory beads found in the Denisova Cave were discovered in the same sediment layers as the Denisovan fossils, leading to suggestions they had sophisticated tools and jewellery.

DNA analysis of a fragment of a fifth digit finger bone in 2010, which belonged to a young girl, revealed they were a species related to, but different from, Neanderthals.

Later genetic studies suggested that the ancient human species split away from the Neanderthals sometime between 470,000 and 190,000 years ago. 

Anthropologists have since puzzled over whether the cave had been a temporary shelter for a group of these Denisovans or it had formed a more permanent settlement.

DNA from molar teeth belonging to two other individuals, one adult male and one young female, showed they died in the cave at least 65,000 years earlier.

Other tests have suggested the tooth of the young female could be as old as 170,000 years.

A third molar is thought to have belonged to an adult male who died around 7,500 years before the girl whose pinky was discovered.

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Pollution regulations to reduce dirty air have saved 1.5 BILLION birds in the US over 40 years

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pollution regulations to reduce dirty air have saved 1 5 billion birds in the us over 40 years

US pollution controls aren’t just good for the atmosphere, they’re saving our winged friends, too.

Ozone gasses, a leading contributor to smog, is linked tied to health problems in both humans and avians. 

A new study found that regulations intended to reduce the pollution have also slowed the decline of bird populations in the US.  

Scientists at Cornell and the University of Oregon tracked changes in bird abundance, ozone emissions and regulation status across the nation over a 15 year period.

Extrapolating their findings, they found caps on ozone emissions may have saved as many as 1.5 billion birds in the past 40 years, – equal to 20 percent of all birds in the United States today.

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A new Cornell study on EPA policies shows

A new Cornell study on EPA policies shows

A new Cornell study on EPA regulations shows efforts to curb ozone production have saved more than a billion birds in the last 40 years. The gas is not only harmful to the animals’ respiratory system, it can kill off the plants and insects they eat

Ozone occurs naturally, but automobiles and power plants have contributed to a significant increase in its production. 

While it’s necessary in the upper atmosphere to protect us from the sun’s ultraviolet rays, at ground level ozone causes smog and contributes to respiratory and cardiovascular disease, especially in the young and the elderly.

Numerous studies have connected ozone at levels currently found in many urban areas to low birth weights, asthma, and even early death.  

It’s also detrimental to bird life, especially the small migratory birds — like sparrows and finches — that make up more than three-quarters of all North American species. 

Ozone is a leading ingredient in smog and has been linked to respiratory illness, cardiovascular disease and low birth weight, among other health risks

Ozone is a leading ingredient in smog and has been linked to respiratory illness, cardiovascular disease and low birth weight, among other health risks

Ozone is a leading ingredient in smog and has been linked to respiratory illness, cardiovascular disease and low birth weight, among other health risks 

As with humans, it impacts their respiratory system — but it can also kill off the plants and insects that serve as their chief food sources.

‘Not surprisingly, birds that cannot access high-quality habitat or food resources are less likely to survive or reproduce successfully,’ said Amanda Rodewald, director of Cornell’s Center for Avian Population Studies and co-author of a new report in Proceedings of the National Academy of Sciences.

‘The good news here is that environmental policies intended to protect human health return important benefits for birds, too.’

To get an idea of how regulations have impacted this country’s winged population, Rodewald and environmental economist Ivan Rudik combined pollution data with environmental policies and bird observations from the Cornell Lab of Ornithology, tracking.

A separate 2019 study by the Cornell Lab of Ornithology showed that North American bird populations have declined by nearly 3 billion birds since 1970

A separate 2019 study by the Cornell Lab of Ornithology showed that North American bird populations have declined by nearly 3 billion birds since 1970

A separate 2019 study by the Cornell Lab of Ornithology showed that North American bird populations have declined by nearly 3 billion birds since 1970

They tracked monthly changes in bird abundance, air quality, and regulation status over 15 years in more than 3,200 counties.

The team focused on the EPA’s NOx (nitrogen oxide) Budget Trading Program, a cap-and-trade initiative launched in 2003 to reduce ozone emissions from power plants and other large industrial sources during the summer months.

A separate 2019 study by the Cornell Lab of Ornithology showed that North American bird populations have declined by nearly 3 billion birds since 1970.

Without existing environmental regulations, Rodewald and Rudik say, an estimated 1.5 billion more birds would have died.

‘Our research shows that the benefits of environmental regulation have likely been underestimated,’ said Rudik. 

‘Reducing pollution has positive impacts in unexpected places and provides an additional policy lever for conservation efforts.’  

The Trump administration has been criticized for rolling back dozens of environmental regulations,

In June 2017, then-EPA administrator Scott Pruitt announced he was delaying enforcement of an Obama-era regulation governing ozone emissions, The New York Times reports.

In August of that year, one day after 16 state attorneys general filed a lawsuit claiming the agency was violating the Clean Air Act, Pruitt reversed his decision and said he would enforce the policy.

Heather McTeer Toney, a former regional EPA administrator under the Obama administration, is among a short-list of candidates being considered to lead the agency under President-elect Biden, Reuters reports. 

This post first appeared on dailymail.co.uk

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Trove of arrows dating back 6,000 years are discovered in Norway after drastic amounts of ice melts 

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trove of arrows dating back 6000 years are discovered in norway after drastic amounts of ice melts

A veritable treasure trove of ancient artifacts has been discovered in an Norwegian ice patch that climate change has caused to melt.

Researchers found nearly 70 arrow shafts, plus shoes, textiles and reindeer bones on a mountainside in Jotunheimen, about 240 miles from Oslo.

Based on radiocarbon dating, the oldest arrows are from around 4100 BC, with the most recent dating from 1300 AD.

While the discovery confirms the region was a popular spot for reindeer hunting millennia ago, it upends conventional wisdom about how ice patches can be used to interpret the historical record.

Archaeologists had assumed the ice preserved items as they were deposited, sealing them in place and providing a timeline — with older relics on the bottom and newer ones on top.

But the different amounts of weathering on the objects, as well as their seemingly random order, counters the theory that ice patches are like photographs, presenting a preserved image of the past.

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A 1,300-year-old arrow discovered at Langfonne. A record-setting 68 arrows were found in all in the Norwegian ice patch, some with their arrowheads still attached

A 1,300-year-old arrow discovered at Langfonne. A record-setting 68 arrows were found in all in the Norwegian ice patch, some with their arrowheads still attached

A 1,300-year-old arrow discovered at Langfonne. A record-setting 68 arrows were found in all in the Norwegian ice patch, some with their arrowheads still attached

A record-setting 68 arrows were found in all, some with their arrowheads still attached.

The heads were made from a variety of materials — iron, quartzite, slate, mussel shell and even bone.

 Several still had the twine and tar used to affix them to a wooden shaft.

The biggest number of arrows dated to 700 through 750 AD, but the oldest were some 6,000 years old.

A 4,000-year-old arrowhead made from quartzite. Other arrow tips were made from slate, bone and sharpened mussel shell.

A 4,000-year-old arrowhead made from quartzite. Other arrow tips were made from slate, bone and sharpened mussel shell.

A 4,000-year-old arrowhead made from quartzite. Other arrow tips were made from slate, bone and sharpened mussel shell.

A 4,000-year-old arrow shaft found on the ice. Based on radiocarbon dating, the oldest arrows are from around 4100 BC, with the most recent dating from 1300 AD

A 4,000-year-old arrow shaft found on the ice. Based on radiocarbon dating, the oldest arrows are from around 4100 BC, with the most recent dating from 1300 AD

A 4,000-year-old arrow shaft found on the ice. Based on radiocarbon dating, the oldest arrows are from around 4100 BC, with the most recent dating from 1300 AD

An aerial photo of Langfonne's three separate main ice patches.  Because of global warming, it is now less than 30 percent of the size it was just two decades ago, according to Pilø

An aerial photo of Langfonne's three separate main ice patches.  Because of global warming, it is now less than 30 percent of the size it was just two decades ago, according to Pilø

An aerial photo of Langfonne’s three separate main ice patches.  Because of global warming, it is now less than 30 percent of the size it was just two decades ago, according to Pilø

‘This is earlier than finds from any other ice site in Northern Europe,’ according to archaeologist Lars Holger Pilø, ‘and about 800 years earlier than Ötzi,’ the 5,100-year-old ice mummy found in the Tyrolean Alps in 1991.

Other artifacts from Langfonne include a well-preserved shoe from more than 3,000 years ago and fabric Pilø says may have been used to package meat.   

The Langfonne ice patch was first uncovered in 2006, when hiker Reidar Marstein discovered a leather shoe from the early Bronze Age there and reported it to Pilø.

At the time, researchers had assumed new layers of snow added to a patch, like strata in the earth, with older layers near the core and newer layers near the surface.

Map of ice sites in Innlandet County. The Langfonne ice patch was first discovered in 2006

Map of ice sites in Innlandet County. The Langfonne ice patch was first discovered in 2006

Map of ice sites in Innlandet County. The Langfonne ice patch was first discovered in 2006

Examples of arrows found at Langfonne. Left shows the nock end of an arrow and right shows a partially preserved arrow shaft in four fragments at the bottom left of the picture

Examples of arrows found at Langfonne. Left shows the nock end of an arrow and right shows a partially preserved arrow shaft in four fragments at the bottom left of the picture

Examples of arrows found at Langfonne. Left shows the nock end of an arrow and right shows a partially preserved arrow shaft in four fragments at the bottom left of the picture

‘The idea was, ice is like a time machine. Anything that lands on it stays there and is protected,’ Pilø, a researcher with the Innlandet County Council Cultural Heritage Department, told National Geographic.

But a closer examination showed the ice melted and re-froze numerous times over the millennia, shifting the arrows around from their original locations.

In addition, if the patch was acting like a time machine, older artifacts should have been just as well preserved as newer ones.

Archaeologists taking samples and artifacts from Langfonne. Analysis of the arrows found on the site disprove the theory that ice patches present a perfectly preserved image of history 'like a time machine'

Archaeologists taking samples and artifacts from Langfonne. Analysis of the arrows found on the site disprove the theory that ice patches present a perfectly preserved image of history 'like a time machine'

Archaeologists taking samples and artifacts from Langfonne. Analysis of the arrows found on the site disprove the theory that ice patches present a perfectly preserved image of history ‘like a time machine’

Instead, the Neolithic arrows were broken and heavily weathered, suggesting they had been exposed to the elements at various times.

The 14th century arrows, though, ‘looked as though they were shot just yesterday,’ National Geographic reported. 

‘This led to a suspicion that something had happened to them while inside the ice,’ Pilø wrote in a blog post on Wednesday.

A view of Langfonne ice patch, from the top of the mountain

A view of Langfonne ice patch, from the top of the mountain

A view of Langfonne ice patch, from the top of the mountain

In a new report in the journal Holocene, Pilø says that makes it hard to glean certain information about the people who used these artifacts.

‘The ice is an artifact-preserver but it is also at the same time a destroyer of history,’ he told Nat Geo.

New discoveries may still present themselves as Langfonne, now split into three smaller patches, continues to thaw.

Its melting is part of a worldwide pattern of retreating mountain glaciers linked to global warming, Pilø wrote.

‘Langfonne has retreated dramatically in the last two decades. It is now less than 30 percent of the size it was 20 years ago. This retreat is clearly visible in the landscape.’

And the patch is only 10 percent of what it was at its height, he said, during the ‘Little Ice Age’ that took place between the 15th and 20th century.

This post first appeared on dailymail.co.uk

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When will Earth be eco-friendly? Most Americans believe the world will be greener by 2042

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when will earth be eco friendly most americans believe the world will be greener by 2042

This year may have been rough, but as 2020 comes to a close many Americans are looking forward to a better future – and a greener one.

A new survey reveals 59 percent foresee a ‘completely environmentally friendly’ Earth by year 2042, but the majority understands that it is only possible if we all work together.

The idea of going green is producing zero waste and running on renewable energy, along with swapping cars for a bicycle or walking and adopting a plant-based diet.

Among ways to create a better world, 70 percent of the respondents also believe climate change is the single biggest threat facing humanity.

A new survey reveals 59 percent foresee a ‘completely environmentally friendly' Earth by year 2042, but the majority understands that it is only possible if we all work together. The idea of going green is producing zero waste and running on renewable energy

A new survey reveals 59 percent foresee a ‘completely environmentally friendly' Earth by year 2042, but the majority understands that it is only possible if we all work together. The idea of going green is producing zero waste and running on renewable energy

A new survey reveals 59 percent foresee a ‘completely environmentally friendly’ Earth by year 2042, but the majority understands that it is only possible if we all work together. The idea of going green is producing zero waste and running on renewable energy

The study was conducted by Cool Effect, which survey 2,000 adults living in the US to understand how Americans feel about climate change and the steps they are willing to take to combat its effects, according to StudyFinds.

The top answers for what a completely environmentally friendly world was a tie of 57 percent for zero waste and using nothing but renewable energy.

Approximately 52 percent said banning single-use plastics, which is a law in eight states currently.

Nearly half of the respondents suggested people bike or walk to their destination instead of driving, while some Americans think an eco-friendly life is a more plant-based diet.

Respondents also suggested swapping cars for a bicycle or walking and adopting a plant-based diet. Among ways to create a better world, 70 percent of the respondents also believe climate change is the single biggest threat facing humanity

Respondents also suggested swapping cars for a bicycle or walking and adopting a plant-based diet. Among ways to create a better world, 70 percent of the respondents also believe climate change is the single biggest threat facing humanity

Respondents also suggested swapping cars for a bicycle or walking and adopting a plant-based diet. Among ways to create a better world, 70 percent of the respondents also believe climate change is the single biggest threat facing humanity

A finding that came out of the new survey shows that a third of those polled have actually switched careers for a more eco-friendly company and 68 percent have or are willing to pack up their lives and move to a more sustainable city

However, although these Americans are willing to fight for a greener world, the research found that many of them are not aware of their own personal carbon footprint – only 36 percent could produce an answer.

The survey also suggests that Americans tend to ignore their personal responsibility  and feel their own carbon footprint is not making an impact on the warming world.

A previous study from 2019 found that some Americans overestimate their contribution – both findings suggests they need to meet in the middle  

However, data from the United States Department of Energy shows the average American emits roughly 17 tons of carbon per year – survey respondents said it was only 11.4 tons.

This post first appeared on dailymail.co.uk

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