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Categories: Paleontology: Climate, Paleontology: Early Mammals and Birds
Published Unveiling 1,200 years of human occupation in Canada's Arctic
(via sciencedaily.com) Original source A recent study provides new insights into ancient cultures in Canada's Arctic, focusing on Paleo-Inuit and Thule-Inuit peoples over thousands of years. Researchers detected human presence and settlements on Somerset Island, Nunavut, by analyzing sediment samples.
Published First ever 3D reconstruction of 52,000-year-old woolly mammoth chromosomes thanks to serendipitously freeze-dried skin
(via sciencedaily.com) Original source An international research team has assembled the genome and 3D chromosomal structures of a 52,000-year-old woolly mammoth -- the first time such a feat has been achieved for any ancient DNA sample. The fossilized chromosomes, which are around a million times longer than most ancient DNA fragments, provide insight into how the mammoth's genome was organized within its living cells and which genes were active within the skin tissue from which the DNA was extracted. This unprecedented level of structural detail was retained because the mammoth underwent freeze-drying shortly after it died, which meant that its DNA was preserved in a glass-like state.
Published The dawn of the Antarctic ice sheets
(via sciencedaily.com) Original source In recent years global warming has left its mark on the Antarctic ice sheets. The 'eternal' ice in Antarctica is melting faster than previously assumed, particularly in West Antarctica more than East Antarctica. The root for this could lie in its formation, as an international research team has now discovered: sediment samples from drill cores combined with complex climate and ice-sheet modelling show that permanent glaciation of Antarctica began around 34 million years ago -- but did not encompass the entire continent as previously assumed, but rather was confined to the eastern region of the continent (East Antarctica).
Published Giant salamander-like creature was a top predator in the ice age before the dinosaurs
(via sciencedaily.com) Original source Meet Gaiasia jennyae, the swamp creature with a toilet seat-shaped head. It lived 40 million years before the first dinosaurs, and it was the top predator in its ecosystem.
Published Extinct humans survived on the Tibetan plateau for 160,000 years
(via sciencedaily.com) Original source Bone remains found in a Tibetan cave 3,280 m above sea level indicate an ancient group of humans survived here for many millennia.
Published Mighty floods of the Nile River during warmer and wetter climates
(via sciencedaily.com) Original source Global warming as well as recent droughts and floods threaten large populations along the Nile Valley. Sediment cores off the Nile mouth reveal insights into the effects and causes of heavy rainfall episodes about 9,000 years ago. That will help to prepare for weather extremes in a changing climate.
Published The evidence is mounting: humans were responsible for the extinction of large mammals
(via sciencedaily.com) Original source Human hunting, not climate change, played a decisive role in the extinction of large mammals over the last 50,000 years. This conclusion comes from researchers who reviewed over 300 scientific articles from many different fields of research.
Published Investigating newly discovered hydrothermal vents at depths of 3,000 meters off Svalbard
(via sciencedaily.com) Original source Hydrothermal vents can be found around the world at the junctions of drifting tectonic plates. But there are many hydrothermal fields still to be discovered. During a 2022 expedition of the MARIA S. MERIAN, the first field of hydrothermal vents on the 500-kilometer-long Knipovich Ridge off the coast of Svalbard was discovered.
Published Last surviving woolly mammoths were inbred but not doomed to extinction
(via sciencedaily.com) Original source The last population of woolly mammoths was isolated on Wrangel Island off the coast of Siberia 10,000 years ago, when sea levels rose and cut the mountainous island off from the mainland. A new genomic analysis reveals that the isolated mammoths, who lived on the island for the subsequent 6,000 years, originated from at most 8 individuals but grew to 200--300 individuals within 20 generations. The researchers report that the Wrangel Island mammoths' genomes showed signs of inbreeding and low genetic diversity but not to the extent that it can explain their ultimate (and mysterious) extinction.
Published Ocean's loss of oxygen caused massive Jurassic extinction: Could it happen again?
(via sciencedaily.com) Original source Researchers have found a chemical clue in Italian limestone that explains a mass extinction of marine life in the Early Jurassic period, 183 million years ago. Volcanic activity pumped out CO2, warming oceans and lowering their oxygen levels. The findings may foretell the impact climate change and oxygen depletion might have on today's oceans.
Published Shocked quartz reveals evidence of historical cosmic airburst
(via sciencedaily.com) Original source Researchers continue to expand the case for the Younger Dryas Impact hypothesis. The idea proposes that a fragmented comet smashed into the Earth's atmosphere 12,800 years ago, causing a widespread climatic shift that, among other things, led to the abrupt reversal of the Earth's warming trend and into an anomalous near-glacial period called the Younger Dryas.
Published Carbon dioxide's heavy stamp on temperature: Doubling CO2 may mean 7 to 14 degree increase
(via sciencedaily.com) Original source A doubling of the amount of CO2 in the atmosphere could cause an increase in the average temperature on earth from 7 to even a maximum of 14 degrees. That is shown in the analysis of sediments from the Pacific Ocean off the coast of California.
Published Tiny New Zealand bird delivers a lesson in birdsong evolution
(via sciencedaily.com) Original source Scientists are rethinking the evolution of vocal learning in birds. New Zealand's smallest bird, the rifleman or titipounamu, may have a rudimentary version of the talent possessed by parrots, hummingbirds and songbirds.
Published The rotation of Earth's inner core has slowed, new study confirms
(via sciencedaily.com) Original source The new study provides unambiguous evidence that the inner core began to decrease its speed around 2010, moving slower than the Earth's surface.
Published Ancient ocean slowdown warns of future climate chaos
(via sciencedaily.com) Original source When it comes to the ocean's response to global warming, we're not in entirely uncharted waters. A new study shows that episodes of extreme heat in Earth's past caused the exchange of waters from the surface to the deep ocean to decline.
Published The solar system may have passed through dense interstellar clouds 2 million years ago, altering Earth's climate
(via sciencedaily.com) Original source Astrophysicists calculate the likelihood that Earth was exposed to cold, harsh interstellar clouds, a phenomenon not previously considered in geologic climate models.
Published Tiny new species of great ape lived in Germany 11 million years ago
(via sciencedaily.com) Original source Ancient apes in Germany co-existed by partitioning resources in their environment, according to a new study.
Published Human activity contributed to woolly rhinoceros' extinction
(via sciencedaily.com) Original source Researchers have discovered sustained hunting by humans prevented the woolly rhinoceros from accessing favourable habitats as Earth warmed following the Last Ice Age.
Published Arctic melting heavily influenced by little-studied meteorological phenomena
(via sciencedaily.com) Original source A team of scientists has combined paleoclimatic data from the last 2,000 years with powerful computer modeling and in-the-field research on lake sediments and tree rings to show that an understudied phenomenon, known as atmospheric blocking, has long influenced temperature swings in the Arctic. As temperatures warm due to climate change, atmospheric blocking will help drive ever-wilder weather events. The study focused on the Norwegian Arctic archipelago, Svalbard, at the edge of the Arctic Ocean.
Published Historic iceberg surges offer insights on modern climate change
(via sciencedaily.com) Original source A great armada entered the North Atlantic, launched from the cold shores of North America. But rather than ships off to war, this force was a fleet of icebergs. And the havoc it wrought was to the ocean current itself. The future of the Atlantic circulation will be determined by a tug-o-war between Greenland's decreasing ice flux and its increasing freshwater runoff.