Month: December 2022

Scientists discovered the oldest known DNA and used it to reveal what life was like 2 million years ago in the northern tip of Greenland. Today, it’s a barren Arctic desert, but back then it was a lush landscape of trees and vegetation with an array of animals, even the now extinct mastodon.

“The study opens the door into a past that has basically been lost,” said lead author Kurt Kjaer, a geologist and glacier expert at the University of Copenhagen.

With animal fossils hard to come by, the researchers extracted environmental DNA, also known as eDNA, from soil samples. This is the genetic material that organisms shed into their surroundings — for example, through hair, waste, spit or decomposing carcasses.

Studying really old DNA can be a challenge because the genetic material breaks down over time, leaving scientists with only tiny fragments.

But with the latest technology, researchers were able to get genetic information out of the small, damaged bits of DNA, said senior author Eske Willerslev, a geneticist at the University of Cambridge. In their study, published Wednesday in the journal Nature, they compared the DNA to that of different species, looking for matches.

The samples came from a sediment deposit called the Kap Kobenhavn formation in Peary Land. Today, the area is a polar desert, Kjaer said.

But millions of years ago, this region was undergoing a period of intense climate change that sent temperatures up, Willerslev said. Sediment likely built up for tens of thousands of years at the site before the climate cooled and cemented the finds into permafrost.

The cold environment would help preserve the delicate bits of DNA — until scientists came along and drilled the samples out, beginning in 2006.

During the region’s warm period, when average temperatures were 20 to 34 degrees Fahrenheit (11 to 19 degrees Celsius) higher than today, the area was filled with an unusual array of plant and animal life, the researchers reported. The DNA fragments suggest a mix of Arctic plants, like birch trees and willow shrubs, with ones that usually prefer warmer climates, like firs and cedars.

The DNA also showed traces of animals including geese, hares, reindeer and lemmings. Previously, a dung beetle and some hare remains had been the only signs of animal life at the site, Willerslev said.

One big surprise was finding DNA from the mastodon, an extinct species that looks like a mix between an elephant and a mammoth, Kjaer said.

Many mastodon fossils have previously been found in what were temperate forests in North America. That’s an ocean away from Greenland, and much farther south, Willerslev said.

“I wouldn’t have, in a million years, expected to find mastodons in northern Greenland,” said Love Dalen, a researcher in evolutionary genomics at Stockholm University who was not involved in the study.

Because the sediment built up in the mouth of a fjord, researchers were also able to get clues about marine life from this time period. The DNA suggests horseshoe crabs and green algae lived in the area — meaning the nearby waters were likely much warmer back then, Kjaer said.

By pulling dozens of species out of just a few sediment samples, the study highlights some of eDNA’s advantages, said Benjamin Vernot, who researches ancient DNA at Germany’s Max Planck Institute for Evolutionary Anthropology and was not involved in the study.

“You really get a broader picture of the ecosystem at a particular time,” Vernot said. “You don’t have to go and find this piece of wood to study this plant, and this bone to study this mammoth.”

Based on the data available, it’s hard to say for sure whether these species truly lived side by side, or if the DNA was mixed together from different parts of the landscape, said Laura Epp, an eDNA expert at Germany’s University of Konstanz who was not involved in the study.

But Epp said this kind of DNA research is valuable to show “hidden diversity” in ancient landscapes.

Willerslev believes that because these plants and animals survived during a time of dramatic climate change, their DNA could offer a “genetic roadmap” to help us adapt to current warming.

Stockholm University’s Dalen expects ancient DNA research to keep pushing deeper into the past. He worked on the study that previously held the “oldest DNA” record, from a mammoth tooth around a million years old.

“I wouldn’t be surprised if you can go at least one or perhaps a few million years further back, assuming you can find the right samples,” Dalen said.

Source: Voice of America

Britain’s Conservative government on Wednesday approved the United Kingdom’s first new coal mine in three decades, a decision condemned by environmentalists as a leap backwards in the fight against climate change.

Hours earlier, the government reversed a ban on building new onshore windfarms in Britain. Opponents called that announcement a cynical attempt to offset criticism of the mine decision.

Cabinet Minister Michael Gove decided the mine in the Cumbria area of northwest England would have “an overall neutral effect on climate change and is thus consistent with government policies for meeting the challenge of climate change,” the government said.

It said coal from the mine would be used to make steel — replacing imported coal — rather than for power generation.

The mine will extract coking coal, the type used in steelmaking, from under the Irish Sea and process it on the site of a shuttered chemical plant in Whitehaven, a town 550 kilometers northwest of London.

Supporters say the mine will bring much-needed jobs to an area hard hit by the closure of its mines and factories in recent decades.

Opponents say the mine is a major blow to the U.K.’s status as a world leader in replacing polluting fossil fuels with clean renewable energy. They argue it will undermine global efforts to phase out coal and make it harder for Britain to meet its goals of generating 100% of electricity from clean energy sources by 2035 and reaching net-zero carbon emissions by 2050.

John Gummer, a Conservative politician who heads the Climate Change Committee, a government advisory body, said the decision “sends entirely the wrong signal to other countries about the U.K.’s climate priorities.”

Doug Parr, policy director at Greenpeace U.K., said “the U.K. government risks becoming a superpower in climate hypocrisy rather than climate leadership. How can we possibly expect other countries to rein in fossil fuel extraction when we’re building new coal mines here?”

Britain has taken steps to bolster its domestic energy supply since Russia’s invasion of Ukraine sent oil and gas prices soaring. The U.K. imports little Russian oil or gas, but its lightly regulated energy market leaves customers highly exposed to price fluctuations.

Many homes and businesses have seen bills double or triple in the past year, though a government price cap — due to end in April — has prevented even steeper hikes.

The invasion of Ukraine has made countries across Europe reconsider plans to cut their use of fossil fuels. Britain has also approved more North Sea oil and gas drilling, while the Czech Republic reversed a plan to stop coal mining in a key region.

France recently restarted a shuttered coal plant, abandoning an earlier vow by President Emmanuel Macron to close all coal-burning plants in the country by the end of this year.

The mine decision came a day after Prime Minister Rishi Sunak lifted a ban on building new windfarms on British soil.

Wind produced more than a quarter of the U.K.’s electricity in 2021. But since 2015, the Conservative government has opposed new wind turbines on land because of local opposition. A majority of Britain’s wind farms are at sea.

While running for the Conservative Party’s leadership in the summer, Sunak pledged to keep the ban. But amid growing calls for change from Conservative lawmakers, the government said Tuesday it could allow wind farms in areas where communities support them, pending a “technical consultation.”

Source: Voice of America