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Italy’s genetic diversity goes back at least 19,000 years, study says

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May 22 (UPI) — Italy has been a genetic melting pot for almost 20,000 years, according to a new study. Nowhere else in Europe hosts a greater mix of genetic heritage.

In addition to the deep history of the region’s genetic diversity, dating to the Late Glacial Maximum, the genomic survey of modern and ancient Italians showed people in the north and south of Italy have evolved unique genetic characteristics in response to the divergent environmental conditions.

The genetic peculiarities of the people of those two regions at least partially explain why these populations a reduced risk of kidney inflammation, certain skin cancers, diabetes and obesity — all of which favor a longer lifespan.

Pockets of Italy are often included on lists of so-called “blue zones,” places and populations characterized by large numbers of octogenarians.

“Gaining an understanding of the evolutionary history of the ancestors of Italians allows us to better grasp the demographic processes and those of environmental interactions that shaped the complex mosaic of ancestry components of today’s European populations,” researcher Marco Sazzini, professor of molecular anthropology at the University of Bologna, said in a news release.

“This investigation provides valuable information in order to fully appreciate the biological characteristics of the current Italian population. Moreover, it let us understand the deep causes that can impact on this population’s health or on its predisposition to a number of diseases.”

For the study, scientists sequenced the genomes of 40 volunteers from across Italy. The participants were selected for their representation of the country’s broad genetic diversity.

Scientists compared the group’s genomic characteristics to the genetic markers of 35 populations from Europe and from the Mediterranean, as well as the genetic variants found among some 600 human remains dating to the Upper Palaeolithic and the Bronze Age — 40,000 and 4,000 years ago, respectively.

The analysis, detailed Friday in the journal BMC Biology, showed modern genomic signatures can be traced back as far as 19,000 years ago — to the period following the last glaciation.

Researchers also compared the genomes of people from northern and southern Italy and traced the emergence of these difference back through the region’s genetic timeline.

“We observe some partially overlapping demographic trends among the ancestors of these two groups from 30,000 years ago and for the remaining years of the Upper Palaeolithic,” said study co-author Stefania Sarno, a researcher at the University of Bologna.

“However, we observed a significant variation between their gene pools from the Late Glacial period, thus some thousands of years before those great migrations that happened in Italy from the Neolithic onward,” Sarno said.

Researchers suspect refugees of the last glaciation period persisted in central Italy before splitting in opposite directions after the glaciers melted. The genomes of northern Italian contain traces of these post-glacial migrations.

Researchers were able to recognize even more ancient signatures in the genomes of northern Italians — genetic signatures unique to eastern European hunter-gatherers that populated large swaths of Europe between 36,000 and 26,000 years ago.

The latest analysis showed these genetic signatures have disappeared in the genomes of southern Italians.

Researchers also identified the genetic effects of the population’s adaptation to millennia of climate change. The populations of northern Italy evolved a metabolism optimized for a high-calorie diet rich in animal fat.

“In the subjects from northern Italy, we observed changes in the gene networks regulating insulin and body-heat production as well as in those responsible for fat tissue metabolism,” said study co-author Paolo Garagnani, professor of experimental medicine and pathophysiology at the University of Bologna.

“These changes could have resulted in key factors reducing the susceptibility to diseases like diabetes and obesity,” Garagnani said.

In southern Italy, populations also evolved genetic characteristics in response the region’s environmental conditions, including coding for the production of mucins, which are protective proteins found in the mucous membranes of the respiratory and gastrointestinal systems.

“These genetic adaptations may have evolved in response to ancient micro-organisms,” said study co-author Paolo Abondio, a doctoral student at the University of Bologna.

“Some scholars have linked some of these genetic variants with a reduced susceptibility to Berger’s disease, which is a common inflammation affecting the kidneys and is indeed less frequent in the south than in the north of Italy,” he said.

Millennia spent the Mediterranean sun also inspired changes to the genes that regulate melanin production — changes that explain the lower incidence of most skin cancers among southern Italians.

“We observed that some of these genetic variants have been also linked to a longer lifespan. This is also true for other genetic modifications, which are characteristic of southern Italians,” said study co-author Claudio Franceschi, emeritus professor at the University of Bologna.



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Astronomers measure spin-orbit alignment of a distant super-Jupiter

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June 29 (UPI) — For the first time, astronomers have measured the spin-orbit alignment of a faraway super-Jupiter exoplanet, located 63 light-years from the Earth in the Pictor constellation.

The super-Jupiter exoplanet, Beta Pictoris b, has a mass 11 times that of Jupiter and enjoys an orbit around its host star similar to the trajectory Jupiter takes around our own sun.

The detailed observations of Beta Pictoris b — shared Monday in the Astrophysical Journal Letters — could help scientists better understand the formation and evolution of planetary systems.

“The degree to that a star and a planetary orbit are aligned with each other tells us a lot about how a planet formed and whether multiple planets in the system interacted dynamically after their formation,” lead study author Stefan Kraus said in a news release.

During the 18th century, scientists Immanuel Kant and Pierre-Simon Laplace noticed that the orbital planes of the solar system’s planets were largely aligned. They estimated that Earth and its planetary neighbors formed from a rotating and flattened protoplanetary disc.

“It was a major surprise when it was found that more than a third of all close-in exoplanets orbit their host star on orbits that are misaligned with respect to the stellar equator,” said Kraus, professor of astronomy and physics at the University of Exeter in Britain.

“A few exoplanets were even found to orbit in the opposite direction than the rotation direction of the star,” Kraus said. “These observations challenge the perception of planet formation as a neat and well-ordered process taking place in a geometrically thin and co-planar disc.”

Using the GRAVITY instrument on the Very Large Telescope in Chile, scientists measured the minuscule spatial displacement caused by the stellar rotation of Beta Pictoris. The data revealed an alignment between the star’s rotational axis and the orbital axis of the planet Beta Pictoris b and its surrounding debris disk.

“Gas absorption in the stellar atmosphere causes a tiny spatial displacement in spectral lines that can be used to determine the orientation of the stellar rotation axis,” said study co-author Jean-Baptiste LeBouquin, an astronomer at the University of Grenoble in France. “The challenge is that this spatial displacement is extremely small: about 1/100th of the apparent diameter of the star, or the equivalent to the size of a human footstep on the moon as seen from Earth.”

The latest findings showed the Beta Pictoris system is just as aligned as our own solar system, but authors of the new study suggest a wider sample size is needed to confirm how common spin orbit alignment is throughout the cosmos.

“A dedicated high-spectral resolution instrument at VLTI could measure the spin-orbit alignment for hundreds of planets, including those on long-period orbits,” said Kraus. “This will help us to answer the question what dynamical processes shape the architecture of planetary systems.”



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Gold mining stunts Amazon rainforest recovery

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June 29 (UPI) — The effects of gold mining on forest health are long lasting. According to new research, gold mining stunts the regrowth of Amazon forests, limiting their ability to store carbon.

“Historically gold mining was often overlooked in deforestation analysis as it occupies relatively small areas when compared to pastures or large-scale agriculture,” lead study author Michelle Kalamandeen told UPI in an email.

Kalamandeen started the research as a postgraduate researcher at the University of Leeds but is now a postdoctoral researcher at Cambridge University.

“Yet, given recent proliferation in mining activities since 2007-2008 and again in 2012, the potential areas may be underestimated and the impact on biodiversity and forest recovery unquantified,” she said.

For the study, Kalamandeen and her colleagues sampled soil and measured trees at 18 test plots in two main gold mining areas in Guyana. Researchers also established two control sites in old-growth forests.

“We measured trees/saplings/seedlings within each plot and took soil samples from abandoned gold mining sites, active sites and control ‘old-growth’ sites,” Kalamandeen said.

The data — published Monday in the Journal of Applied Ecology — showed trees in forests damaged by gold mining activity struggled to reestablish themselves. Where as forest harmed by other kinds of activities, such as logging and agriculture, were able to rebound, the negative effects of mining on growth and carbon storage persisted.

“Our analysis showed that the lack of nitrogen was the primary driving force for the lack of recovery occurring on the tailing ponds and mining pits,” Kalamandeen said. “On the overburden, where there was an abundance of nitrogen, regrowth of trees were similar to other Neotropical secondary, recovery forests.”

Researchers were surprised to find that a lack of nitrogen, instead of an excess of mercury, was to blame for the stunted regrowth.

“Our research showed that active mines had on average 250 times more mercury than abandoned mining sites, suggesting that this mercury leaches into neighboring forests and rivers,” Kalamandeen said.

Researchers found that in the few mining sites where topsoil was replaced and fertilized with nitrogen — an often mandated, but rarely enforced, restoration step — regrowth was comparable to plots where trees were cleared for other types of activity.

Scientists hope their findings will inspire politicians and policy makers in the Amazon to strengthen environmental regulations for gold mining.

“It’s important the current environmental policies are enforced. Most Amazonian countries have reasonable monitoring and enforcement policies but weakening of such policies or reduced funding to regulatory agencies as we’ve seen in Brazil and Venezuela, means that enforcement isn’t occurring,” Kalamandeen said.

“Addressing corruption in mining agencies is also another issue that needs addressing at the national scale,” Kalamandeen said. “For restoration, many Amazonian countries don’t have a forest restoration policy when it comes to gold mining and this needs to be tested and developed for tropical forests at the landscape-scale.”

Gold prices often rise in the wake of economic crises, and when they do, small-scale gold mining activity ramps up in the Amazon.

Though under new leadership, Brazil has recently been weakening environmental regulations. But in the years that followed the financial crisis, strong rainforest protections forced miners to pursue gold in neighboring countries, especially the dense forests of Guyana and the French Guiana.

With the COVID-19 pandemic putting a significant dent in global economic growth, researchers worry gold mining activity will once again proliferate across a large stretch of forest known as the Guiana Shield. In the future, scientists hope to test new technologies designed to curb the threat of gold mining.

“We hope to use remote sensing to help detect gold mining especially illegal mining within the Amazon,” Kalamandeen said.



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Ancient Japanese birds looked a lot like New Zealand’s monster penguins

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June 29 (UPI) — New analysis suggests New Zealand’s giant penguins and a much younger group of Northern Hemisphere birds, the plotopterids, were physically quite similar.

The research, published Monday in the Journal of Zoological Systematics and Evolutionary Research, could help scientists figure out how birds evolved wings better suited for swimming than flying.

Fossil remains suggest as many as nine different species once swam the tropical seas that washed over most of what’s now New Zealand, some 62 million years ago. While some species were the size of modern penguins, others grew to heights of more than five feet.

Plotopterids don’t appear in the Northern Hemisphere fossil record until 30 million years later. Their remains have been recovered from several sites in Japan and North America. Like penguins, plotopterids used flipper-like wings to navigate coastal seas. But while the relatives of New Zealand’s ancient penguins can still be found today, plotopterids went extinct around 25 million years ago.

For the new study, scientists compared the fossilized remains of plotopterids recovered from Japan with the fossils of three giant penguin species. In addition to boasting similar wings, the analysis showed both groups of birds possessed long beaks with slit-like nostrils, as well as chest and shoulder bones conducive to swimming. Like the giant penguins, some plotopterid species were oversized, growing to heights of more than six feet.

Despite their physical similarities, plotopterids and penguins aren’t particularly close relatives. Plotopterids are more closely related to other seaworthy birds like boobies, gannets and cormorants.

“What’s remarkable about all this is that plotopterids and ancient penguins evolved these shared features independently,” study co-author Vanesa De Pietri, curator at the Canterbury Museum in New Zealand, said in a news release. “This is an example of what we call convergent evolution, when distantly related organisms develop similar morphological traits under similar environmental conditions.”

Though plotopterids and giant penguins were separated by several thousand miles and nearly 30 million years, had they lived side-by-side, they would have been hard to distinguish.

“Plotopterids looked like penguins, they swam like penguins, they probably ate like penguins — but they weren’t penguins,” said Paul Scofield, study co-author and Canterbury curator.

The newly published comparison of the two ancient bird groups has helped scientists begin to develop an explanation for why some birds developed wings for swimming.

“Wing-propelled diving is quite rare among birds; most swimming birds use their feet,” said study co-author Gerald Mayr, scientist at the Senckenberg Research Institute and Natural History Museum in Germany.

“We think both penguins and plotodopterids had flying ancestors that would plunge from the air into the water in search of food,” Mayr said. “Over time these ancestor species got better at swimming and worse at flying.”



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