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Categories: Ecology: Extinction, Paleontology: Climate
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 To protect corals from summer heatwaves, we should help their microbial symbionts evolve heat tolerance in the lab
(via sciencedaily.com) Original source Most coral reef restoration efforts involve restocking reefs with nursery-grown corals. However, if these corals are of the same stock as their wild counterparts, they will be equally vulnerable to the heat stress that caused the bleaching event in the first place. Researchers discuss the potential of improving corals' chances by inducing the evolution of heat tolerance in their symbionts -- the mutualistic microbes that provide corals with nutrients in exchange for shelter and that are expelled during coral bleaching.
Published Future risk of coral bleaching set to intensify globally
(via sciencedaily.com) Original source Researchers have projected future marine heatwaves will cause coral reefs to be at severe risk of bleaching for longer periods than previously seen.
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 Frog 'saunas' a lifeline for endangered frog populations
(via sciencedaily.com) Original source New biologist-designed shelters will help endangered frogs survive the devastating impacts of a deadly fungal disease by regulating their body temperature to fight off infections.
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 Boosting biodiversity without hurting local economies
(via sciencedaily.com) Original source Protected areas, like nature reserves, can conserve biodiversity without harming local economic growth, countering a common belief that conservation restricts development. A new study outlines what is needed for conservation to benefit both nature and people.
Published Insecticides contributed to loss of butterflies across American Midwest, study finds
(via sciencedaily.com) Original source Insecticide use is a major factor causing a decrease in the size and diversity of butterfly populations across the US Midwest, according to a new study.
Published Natural hazards threaten over three thousand species
(via sciencedaily.com) Original source Natural hazards can speed up the extinction process of land animals that have limited distribution and/or small populations. But there is hope to turn the negative development around, says researchers behind new study.
Published Restored rat-free islands could support hundreds of thousands more breeding seabirds
(via sciencedaily.com) Original source Archipelago case-study shows that removing invasive rats and restoring native vegetation could help bring back hundreds of thousands of breeding pairs of seabirds lost to tropical islands. Calculating that there are enough fish to sustain restored seabird populations should be an important consideration for restoration projects, scientists say. Restored seabird populations also provide huge boost to the health of surrounding coral reef ecosystems through restored nutrient cycles.
Published Nile perch invasion triggered genetic bottlenecks in Lake Victoria's endemic cichlids
(via sciencedaily.com) Original source Newfound evidence reveals that the upsurge of the exotic Nile perch in Lake Victoria had long-lasting effects on the genetic diversity of various local cichlid species, report scientists. Through large-scale comparative genomic analyses, the researchers found concrete proof in the collective genome of multiple species that this artificially introduced perch decimated many local fish populations, causing a 'bottleneck effect.'
Published 'Lost' birds list will aid in protecting species
(via sciencedaily.com) Original source A group of scientists has released the first comprehensive list of birds that haven't been documented with sound or video in more than a decade.
Published Ancient polar sea reptile fossil is oldest ever found in Southern Hemisphere
(via sciencedaily.com) Original source An international team of scientists has identified the oldest fossil of a sea-going reptile from the Southern Hemisphere -- a nothosaur vertebra found on New Zealand's South Island. 246 million years ago, at the beginning of the Age of Dinosaurs, New Zealand was located on the southern polar coast of a vast super-ocean called Panthalassa. 'The nothosaur found in New Zealand is over 40 million years older than the previously oldest known sauropterygian fossils from the Southern Hemisphere.
Published Sharks have depleted functional diversity compared to the last 66 million years
(via sciencedaily.com) Original source New research has found that sharks retained high levels of functional diversity for most of the last 66 million years, before steadily declining over the last 10 million years to its lowest value in the present day.
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 Specialist and migratory birds at greater risk under climate change
(via sciencedaily.com) Original source Following decades of decline, even fewer birds will darken North American skies by the end of the century, according to a new analysis. The study examines the long-term effects of climate change on the abundance and diversity of bird groups across the continent as a whole while accounting for additional factors that put birds at risk.
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 Scientists 'read' the messages in chemical clues left by coral reef inhabitants
(via sciencedaily.com) Original source What species live in this coral reef, and are they healthy? Chemical clues emitted by marine organisms might hold that information. But in underwater environments, invisible compounds create a complex 'soup' that is hard for scientists to decipher. Now, researchers have demonstrated a way to extract and identify these indicator compounds in seawater. They found metabolites previously undetected on reefs, including three that may represent different reef organisms.