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Ancient genomes reveal 7,000 years of demographic history in France

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May 26 (UPI) — According to new genomic analysis, France was populated by a pair of ancient migrations: the first during the Neolithic period, roughly 6,300 years ago, and the second during the Bronze Age, some 4,200 years ago.

“There were almost no data from ancient populations on the territory of present-day France and our study begins to fill a gap that leads to a clearer picture of the evolution of populations throughout Europe,” Eva-Maria Geigl, a researcher with the Jacques Monod Institute in Paris, told UPI in an email.

For the new study, researchers in France generated and analyzed the mitochondrial genomes, Y-chromosome markers and genotypes of 243 individuals, whose remains were recovered from dig sites across present-day France. The dates of the individuals comprised a period spanning 7,000 years.

The analysis — detailed Tuesday in the journal PNAS — revealed several new insights into France’s demographic history, including the persistence of Magdalenian-associated ancestry in hunter-gatherer populations, previously thought to be to relegated to Spain’s Iberian Peninsula.

The new data showed these Magdalenian-associated ancestors were joined in what is now France by Anatolian farmers some 6,300 years ago. The two groups begin mixing during the Neolithic, with admixtures becoming increasingly prevalent in the genomic data by the end of the Neolithic, some 6,400 B.C.

“The admixture with Mesolithic hunter-gatherers harboring ancestry of the population associated with the Magdalenian culture has so far not been reported north of the Iberian Peninsula,” Institut Jacques Monod researcher Thierry Grange said. “We show that it is a definitive feature of Western Europe.”

Parental lineages and genomic data revealed demographic patterns in France similar to those observed in neighboring regions, but offered new details in regards to distribution of Magdalenian-associated hunter-gatherers and the timing of the arrival of Neolithic farmers.

“The genomes of all of our Neolithic farmers harbor the Anatolian Neolithic genome component. The migration went from northwestern Anatolia into southeast Europe in the 7th millennium BC,” Geigl said. “The Neolithic farmers moved northward to Hungary and then westward throughout Europe and arrived in western France around 5350 BC.”

After a few dozen centuries of admixing between the lineages of hunter gatherers and lineages of Anatolian farmers, the region received an influx of new genetic heritage from migrants hailing from the Pontic steppe.

“The admixture with steppe herders during the Bronze Age led to a replacement of the paternal lineages, Y chromosome, that lasts up to now,” Grange said.

In future studies, researchers hope to narrow the temporal scale of their analysis to hone in on the details of demographic dynamics in prehistoric France.

“Our group at the Jacques Monod Institute will analyze more individuals and attempt a higher genome coverage in order to increase the resolution of the analysis so that we can obtain more information about the functioning of these societies,” Geigl said.

“We will focus on more individuals from shorter time spans to have a better resolution of the protohistoric events, and also to get a better understanding of the evolution of genetic changes that led to the genetic structure of the present-day populations, in particular those that underlie our beneficial adaptations but also our detrimental inadequacies,” Geigl added.



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Florida Current study confirms decline in strength of Gulf Stream

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Aug. 7 (UPI) — New research suggests the strength of the Florida Current, which forms the beginning of the Gulf Stream, has weakened considerably over the last century.

The findings, published Friday in the journal Nature Climate Change, corroborate the predictions of several models that suggest the Gulf Stream has slowed over the last several decades.

The Florida Current is a thermal ocean current that flows from west to east around the tip of Florida, joining the Gulf Stream off Florida’s east coast.

Scientists have been tracking the strength of the Florida Current since the early 1980s — not long enough to identify multi-decadal or centennial trends.

To better understand the current’s historical changes, Christopher Piecuch, researcher at the Woods Hole Oceanographic Institution in Massachusetts, decided to study the relationship between coastal sea level and the strength of near-shore currents.

While researchers have only been measuring the Florida Current for a few decades, scientists have been recording sea level data since the early 1900s. Piecuch was able to use the data to predict historic changes in the strength of near-shore currents.

“In the ocean, almost everything is connected,” Christopher Piecuch, sole author of the new study, said in a news release. “We can use those connections to look at things in the past or far from shore, giving us a more complete view of the ocean and how it changes across space and time.”

The statistical analysis performed by Piecuch showed the Florida Current and Gulf Stream are the weakest they’ve been during the last 110 years.

The findings are in agreement with ocean current models that suggest climate change has caused a slowdown of the Atlantic Meridional Overturning Circulation, of which the Gulf Stream is a part.

Piecuch said he hopes his research will help other scientists use coastal current data to study changes in bigger currents like the Gulf Stream.

“If we can monitor something over the horizon by making measurements from shore, then that’s a win for science and potentially for society,” he said.



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SpaceX, ULA win large government launch contracts

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Astronauts make round trip to space station from U.S. soil

NASA astronaut Douglas Hurley (C) waves to onlookers as he boards a plane at Naval Air Station Pensacola to return him and NASA astronaut Robert Behnken home to Houston a few hours after the duo landed in their SpaceX Crew Dragon Endeavour spacecraft off the coast of Pensacola, Fla,, on August 2, 2020. Photo by Bill Ingalls/NASA | License Photo



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High levels of mercury, plastic toxins found in stranded whales, dolphins

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ORLANDO, Fla., Aug. 10 (UPI) — Dolphins and whales stranded on beaches in the southeastern United States had high levels of toxins, including mercury and chemicals found in plastic, according to a study published in the journal Frontiers in Marine Science.

Scientists who led the study said the data provides new, troubling information about the impact of pollution on marine mammals — knowledge that could help save vulnerable and declining species.

The findings also could be a warning for humans, because whales and dolphins eat seafood that people also eat, researchers said.

“We must do our part to reduce the amount of toxicants that enter into our marine environment, which have important health and environmental implications not just for marine life, but for humans,” lead author Annie Page-Karjian said.

“Dolphins eat a variety of fish and shrimp in these marine environments and so do humans,” said Page-Karjian, an assistant research professor of marine wildlife at Harbor Branch Oceanographic Institute in Fort Pierce, Fla.

Besides plastic chemicals, the study found toxins in the animals that included mercury, triclosan — an antibacterial agent used in consumer products like in soap and toothpaste — and atrazine, an herbicide.

The study, published last week, examined tissue from 83 dolphins and whales that became stranded from North Carolina to south Florida and died from 2012 to 2018. Eleven animal species were tested for 17 toxins.

The study is the first to report concentrations of toxicants in a white-beaked dolphin and in Gervais’ beaked whales, species for which the scientific literature remains sparse.

The researchers involved in the study are licensed to retrieve bodies of marine mammals nationally and internationally as part of a network to respond to the stranding of marine animals.

Such science collected from the dead animals is difficult to collect from live animals, and the stranded animals often are in stages of sickness or decay, said Justin Perrault, another study participant, who is director of research at Loggerhead Marinelife Center Juno Beach, Fla.

“Some of the mercury levels we found were the highest found anywhere in the world,” Perrault said. “It is eye-opening. To see the levels of some of these contaminants is alarming.”

Despite those high levels, the study was unable to determine if the toxins caused the animals to beach themselves, said James Sullivan, executive director at Harbor Branch.

“It’s really hard to judge, when an animal strands, if the toxins in the animal were related to why it stranded,” Sullivan said. “But these health problems do stack up. The animal is much more susceptible to succumbing to natural disease and environmental problems, just like humans are more likely to get ill from coronavirus if they have underlying conditions.”

Although the study focused on the Southeast, it has broader implications for marine mammal conservation, said John Calambokidis, senior research biologist with Olympia, Wash.-based Cascadia Research.

“There are many things we do not know about how many contaminants accumulate and might impact marine mammals,” Calambokidis said. “This is valuable especially because there are so many chemicals that are used by humans and enter the environment and many are not tested for.”



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