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World’s oldest DNA sequenced from million-year-old mammoths – Al Jazeera English

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Teeth from mammoths buried in the Siberian permafrost for more than a million years have yielded the oldest DNA ever sequenced, according to a study published on Wednesday, shining a genetic spotlight into the deep past.

Researchers said the three specimens, one roughly 800,000 years old and two more than a million years old, provide important insights into the giant Ice Age mammals, including the ancient heritage of the woolly mammoth.

The genomes far exceed the oldest previously sequenced DNA – a horse dating to between 780,000 and 560,000 years ago.

“This DNA is incredibly old. The samples are a thousand times older than Viking remains, and even predate the existence of humans and Neanderthals,” said Love Dalen, a professor of evolutionary genetics at the Centre for Palaeogenetics in Stockholm and the senior author of the study published in the journal, Nature.

The mammoths were originally discovered in the 1970s in Siberia and held at the Russian Academy of Sciences in Moscow.

Researchers first dated the specimens geologically, with comparisons to other species, like small rodents, known to be unique to particular time periods and found in the same sedimentary layers.

This suggested that two of the mammals were ancient steppe mammoths more than a million years old.

The youngest of the trio is one of the earliest woolly mammoths yet found.

DNA jigsaw

Researchers also extracted genetic data from tiny samples of powder from each mammoth tooth, “essentially like a pinch of salt you would put on your dinner plate,” Dalen told a press briefing.

A woolly mammoth tusk emerges from the permafrost on central Wrangel Island in northeastern Siberia. Analysis of teeth from the animals has yielded the oldest DNA ever sequenced [Love Dalén via AFP]

While it had degraded into very small fragments, scientists were able to sequence tens of millions of chemical base pairs, which make up the strands of DNA and conduct age estimates from the genetic information.

This suggested that the oldest mammoth, named Krestovka, is even older at approximately 1.65 million years old, while the second, Adycha, is about 1.34 million years old and the youngest Chukochya is 870,000 years old.

Dalen said the discrepancy for the oldest mammoth could be an underestimation in the DNA dating process, meaning the creature was likely around 1.2 million years old, as suggested by the geological evidence.

But he said it was possible the specimen was indeed older and had thawed out of the permafrost at one point and then become wedged in a younger layer of sediment.

The DNA fragments were like a puzzle with millions of tiny pieces, “way, way, way smaller than you would get from modern, high-quality DNA”, said lead author Tom van der Valk, of the Science for Life Laboratory, Uppsala University.

Using a genome from an African elephant, a modern relative of the mammoth, as a blueprint for their algorithm, researchers were able to reconstruct parts of the mammoth genomes.

The study found that the older Krestovka mammoth represents a previously unrecognised genetic lineage, which researchers estimated diverged from other mammoths around two million years ago and was ancestral to those that colonised North America.

The study also traced the lineage from the million-year-old Adycha steppe mammoth to Chukochya and other more recent woolly mammoths.

It found gene variants associated with life in the Arctic, like hairiness, thermoregulation, fat deposits and cold tolerance in the older specimen, suggesting mammoths were already hairy long before the woolly mammoth emerged.

Ice Age giants

Siberia has alternated between dry and cold Ice Age conditions and warm, wet periods.

Now climate change is melting the permafrost and revealing more specimens, Dalen said, although increased rainfall could mean remains are washed away.

He said new technologies mean it may be possible to sequence even older DNA from remains found in the permafrost, which dates back 2.6 million years.

Researchers are keen to look at creatures such as the ancestors of moose, muskox, wolves and lemmings, to shine a light on the evolution of modern species.

“Genomics has been pushed into deep time by the giants of the Ice Age,” said Alfred Roca, a professor in the Department of Animal Sciences at the University of Illinois, in a comment piece published in Nature.

“The wee mammals that surrounded them might soon also have their day.”

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Outbreak reported at Peterborough student residence – ThePeterboroughExaminer.com

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A gathering last week has led to a COVID-19 outbreak at a local student residence and the closure of the building to visitors.

There are six confirmed cases at Severn Court, at 555 Wilfred Drive, health officials confirmed Saturday. A Section 22 order was issued Saturday by Dr. Rosana Salvaterra, closing the building to visitors and requiring residents to self-isolate. Anyone who visited the building between Feb. 20 and 27 is asked to self-isolate and get tested if they show symptoms.

“Based on initial investigations, several of the exposures occurred during a private gathering on Feb. 20,” Peterborough Public Health reports in a press release.

“This outbreak is very concerning not only because it involves a variant of concern and could lead to many more cases and high-risk contacts, but because it was also completely preventable,” stated Salvaterra.

The specific strain of variant is not yet known.

The privately run student residence, located near Fleming College, has about 200 post-secondary students as tenants. Salvaterra said representatives of the Severn Court Management Company have been working with health officials to contain the spread, as have Trent University and Fleming College.

The news comes as Peterborough Public Health reports eight new cases of COVID-19 in the area Saturday.

The health unit, which tracks cases confirmed in the city and county, Curve Lake First Nation and Hiawatha First Nation, reports that there have now been 635 cases of COVID-19 since last March. Of those, 582 have been resolved.

One of those cases has involved a COVID-19 variant.

There are currently 41 active cases. There have been nine deaths.

An outreak has also been reported at Empress Gardens.

Vaccinations at Curve Lake are scheduled over two days next week, on Wednesday and on March 6. About 1,000 residents who signed up are scheduled to get their first dose of the Pfizer vaccine over the two days.

Getting tested

More than 43,400 residents, or 29.3 per cent, have been tested at least once for the virus, the health unit reportes.

COVID-19 testing continues at Peterborough Regional Health Centre and at Northcrest Arena, both by appointment only. To book a spot, visit prhc.on.ca and at peterboroughpublichealth.ca.

Testing by Peterborough Public Health staff can also be arranged in the home by calling 705-743-1000.

Some people can be tested at the Shoppers Drug Mart at High and Lansdowne streets, by appointment. Call 705-748-6141 or email asdm614@shoppersdrugmart.ca to book an appointment.

This is specifically for people who meet certain criteria: Asymptomatic students, teachers and staff in schools and child-care settings; Residents or workers in long-term care homes; Visitors to a long-term care home; Residents or workers in homeless shelters; International students who have passed their 14-day quarantine period; Farm workers; Self-identified Indigenous people.

Neighbouring areas

There were three new cases reported Saturday across the area covered by the Haliburton Kawartha Pine Ridge District Health Unit Saturday, all three in Northumberland County.

No new cases were reported in Haliburton or in the City of Kawartha Lakes.

There have been 1,029 cases confirmed in the area since last March, with 53 confirmed deaths and 13 probably COVID-19 deaths.

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Twelve people tested positive for the N501Y mutation of the coronavirus – two in the City of Kawartha Lakes and 10 in Northumberland County.

In Durham Region, there were 34 new cases confirmed Saturday, with 260 active cases and 23 people in hospital.

There were two COVID-19 deaths in Durham over the past week, for a total of 295 since the pandemic began.

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Fireball caught on-camera over the sky in Chatham, Ont. – Global News

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Those looking out at the night sky in Southwestern Ontario Friday night might have spotted a shooting star, or as it’s technically known, a fireball shooting across the sky.

This event was captured by several all-sky meteor cameras belonging to the NASA All Sky Fireball Network and the Southern Ontario Meteor Network, operated by Western University.

Peter Brown, Professor and Canada Research Chair of Meteor Physics Western Institute for Earth & Space Exploration, reported on Twitter the fireball was as bright as the moon and passed directly over Chatham, Ont.

Read more:
Fireball that lit up Prairie sky was a comet fragment travelling 220,000 km/h: University of Alberta

He said the event happened Friday at 10:07 p.m. and that the fireball ended at 30 km height just north of Lake St. Claire near Fair Haven, Michigan.

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In a tweet, he wrote “very small or no meteorites likely.”

According to NASA, the video data shows that the meteor appeared 90 kilometres above Erieau on the northern shore of Lake Erie and moved northwest at a speed of 105,800 kilometres per hour, crossing the U.S./Canada border before eroding over Fair Haven, Michigan.

NASA reports the meteor was likely caused by a fragment of a Jupiter family comet, though an asteroidal origin is also possible.

The space agency estimates the brightest of the fireball combined with the speed means any fragment would be at least two kilograms and around five inches in size.

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Manitoba company helps land Perseverance rover on Mars with high-speed camera – CBC.ca

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It’s only about the size of a loaf of bread. But a high-speed, tough-as-nails camera created by a company in Minnedosa, Man., played an instrumental role in landing NASA’s Perseverance rover on Mars last week.

“You could run over it, it could fall, you could throw it out your window. That’s how tough they need to be,” Canadian Photonic Labs president Mark Wahoski said of the camera used in the monumental landing on Feb. 18.

His company, based in the southwestern Manitoba town — population around 2,500 — manufactures high-speed cameras for industrial, scientific and military markets, according to its website.

It took years to design the Perseverance camera in a way that would allow it to withstand the planet’s gravitational force — and snap images fast enough, Wahoski told host Marjorie Dowhos on CBC’s Radio Noon on Friday.

“It’s really hard to comprehend just how fast that is,” he said. “They go anywhere from normal, 30 frames per second — like your cellphone camera — all the way up to 250,000 frames per second.”

And the testing involved to make sure it’s up to the task before it gets sent into space is just as complex.

One of the simulations involved sending a metal sled with rocket engines strapped on top of it down a five-mile railroad bed in California, Wahoski said.

Another saw a helicopter lift a parachute, tied to that same rocket sled, up thousands of feet in the air before sending the sled down the track.

“On one of the tests, they determined they had to make this particular part stronger. So without those tests, the lander probably would not make it,” Wahoski said.

The Manitoba company’s relationship with NASA dates back roughly 15 years, he said — but much of the work that’s happened in that time has been cloaked in secrecy.

“A lot of it you can’t speak about…. You do the test and you do the support and you move on to the next project,” he said.

However, the attention around the Perseverance rover landing has been an exciting development, Wahoski said.

This photo provided by NASA shows the first color image sent by the Perseverance Mars rover after its landing on Feb. 18. (NASA/JPL-Caltech/The Associated Press)

Once the landing finally happened, he said he had one word to describe how he felt: awesome.

“We had to just reflect back and say, ‘Oh gee, yeah, we did some of that.'”

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