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Categories: Archaeology: General, Ecology: Research

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Scientists have used paleogenomics to trace 10,000 years of human immune system evolution. They analyzed the genomes of more than 2,800 individuals who lived in Europe over the past ten millennia. They were able to date the increase in frequency of most of the mutations that are advantageous in defending against pathogens to after the Bronze Age, 4,500 years ago. The scientists also observed that mutations conferring a higher risk of developing inflammatory disorders have become more frequent over the past 10,000 years.

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The movement of people across the Bering Sea from North Asia to North America is a well-known phenomenon in early human history. Nevertheless, the genetic makeup of the  people who lived in North Asia during this time has remained mysterious due to a limited number of ancient genomes analyzed from this region. Now, researchers describe genomes from ten individuals up to 7,500 years old that help to fill the gap and show geneflow from people moving in the opposite direction from North America to North Asia.

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The analysis of ancient DNA allows scientists to trace human evolution and make important discoveries about modern populations. The data revealed by ancient DNA sampling can be valuable, but the human remains that carry this ancient DNA are often those of the ancestors of modern Indigenous groups, and some communities have expressed concerns about the ethics of sampling by outside parties. A group of scientists make the case for involvement of descendant communities in all aspects of the research process.

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When it comes to preserving the world's coral reefs, what's going on above the surface is as important as what's going on below it, according to new research.

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Climate change will reshape ecosystems through two types of events: short-term, extreme events -- or 'pulses' -- and long-term changes, or 'presses.' Understanding the effects of presses and pulses is essential as conservationists and policymakers try to preserve ecosystems and safeguard biodiversity. Researchers have discovered how different presses and pulses impacted Magellanic penguins -- a migratory marine predator -- over nearly four decades and found that, though individual presses and pulses impacted penguins in a variety of ways, both were equally important for the future survival of the penguin population. They also found that these types of climate changes, taken together, are leading to an overall population decline at their historically largest breeding site.

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Save the ... parasites? Analyzing 140 years of parasite abundance in fish shows dramatic declines, especially in parasites that rely on three or more host species. The decline is linked to warming ocean temperatures. Parasitic species might be in real danger, researchers warn -- and that means not just fewer worms, but losses for the entire ecosystem.

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Smallpox was once one of humanity's most devastating diseases, but its origin is shrouded in mystery. For years, scientific estimates of when the smallpox virus first emerged have been at odds with historical records. Now, a new study reveals that the virus dates back 2,000 years further than scientists have previously shown, verifying historical sources and confirming for the first time that the disease has plagued human societies since ancient times.

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Researchers suggest that rising levels of humanmade chemicals, accumulating in marine plankton, might be used to monitor the impact of human activity on ecosystem health and perhaps study links between ocean pollution and land-based rates of childhood and adult chronic illnesses.

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An unexpected ancient manufacturing strategy may hold the key to designing concrete that lasts for millennia.

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This study, conducted from 2015-19 in the Thunder Basin National Grassland, may be the first to specifically examine the multispecies impacts of a wide-scale plague outbreak, which reduced the area covered by prairie dog colonies from nearly 25,000 acres to only about 125 acres in the study area. The 2017 outbreak was followed by abnormally high precipitation in 2018, which caused vegetation to grow quickly and taller without the presence of prairie dogs. The researchers found that the mountain plover, birds that thrive when vegetation is kept shorter by prairie dogs, almost disappeared from the study area, while migrant songbirds such as the lark bunting, which prefer taller vegetation, increased in number. Meanwhile, species including ferruginous hawks, badgers and swift foxes declined dramatically as their prey base crashed.

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Scientists have discovered for the first time that invasive rats on tropical islands are affecting the territorial behavior of fish on surrounding coral reefs. The new study shows that the presence of invasive black rats on tropical islands is causing changes in the territorial behavior of the jewel damselfish -- a herbivorous species of tropical reef fish that 'farm' algae in the branches of corals.

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A new study based on 297 ancient Scandinavian genomes analysed together with the genomic data of 16,638 present day Scandinavians resolve the complex relations between geography, ancestry, and gene flow in Scandinavia -- encompassing the Roman Age, the Viking Age and later periods. A surprising increase of variation during the Viking period indicates that gene flow into Scandinavia was especially intense during this period.

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What genetic changes are responsible for the evolution of phenotypic traits? This question is not always easy to answer. A newly developed method now makes the search much easier.

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More than 500 years ago in the midwestern Guatemalan highlands, Maya people bought and sold goods with far less oversight from their rulers than many archeologists previously thought. Overtime, the availability of obsidian resources and the prevalence of craftsmen to shape it resulted in a system that is in many ways suggestive of contemporary market-based economies.

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Researchers have revealed the effects of high pathogenicity avian influenza virus infection on an Ezo red fox and a Japanese raccoon dog, linking their infection to a recorded die-off of crows.

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A new study that reconstructs the history of sea level at the Bering Strait shows that the Bering Land Bridge connecting Asia to North America did not emerge until around 35,700 years ago, less than 10,000 years before the height of the last ice age (known as the Last Glacial Maximum). The findings indicate that the growth of the ice sheets -- and the resulting drop in sea level -- occurred surprisingly quickly and much later in the glacial cycle than previous studies had suggested.

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Archaeologists have uncovered projectile points in Idaho that are thousands of years older than any previously found in the Americas, helping to fill in the history of how early humans crafted and used stone weapons.

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Existing conservation efforts are insufficient to protect Antarctic ecosystems, and population declines are likely for 65% of the continent's plants and wildlife by the year 2100, according to a new study.

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Ocean warming is driving an increase in the frequency and severity of marine heatwaves, causing untold damage to coral reefs. Tropical corals, which live in symbiosis with tiny single celled algae, are sensitive to high temperatures, and exhibit a stress response called bleaching when the ocean gets too hot. In the last 4 decades, marine heatwaves have caused widespread bleaching, and killed millions of corals. Because of this, a global search is underway for reefs that can withstand the heat stress, survive future warming, and act as sources of heat-tolerant coral larvae to replenish affected areas both naturally and through restoration.

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Spread across vast distances, the islands of the tropical Pacific Ocean are thought to have been populated by humans in two distinct migrations beginning approximately 3,330 years ago. The first followed a northern route out of what is today the Philippines and the second followed a southern route from Taiwan and New Guinea. People arrived on the islands between these routes -- now making up the Federated States of Micronesia -- about 1,000 years later. But a new finding by sea-level researchers suggests that the islands in Micronesia were possibly settled much earlier than supposed and that voyagers on the two routes may have interacted with one another.