Agriculture accelerated human genome evolution to capture energy from starchy foods

New study finds rapid increase over last 12,000 years in genes for enzymes that digest starch

Date: September 4, 2024

Source: University of California - Berkeley

Summary:

Scientists have suspected that modern humans have more genes to digest starch than our hunter-gatherer ancestors, but the amylase locus of the genome is hard to study. Researchers have now developed new methods to isolate the multiple amylase genes and compare the locus to ancient genomes. They found that amylase gene number has increased from an average of eight to more than 11 over the past 12,000 years.


FULL STORY

Over the past 12,000 years, humans in Europe have dramatically increased their ability to digest carbohydrates, expanding the number of genes they have for enzymes that break down starch from an average of eight to more than 11, according to a new study by researchers from the U.S., Italy and United Kingdom.


The rise in the number of genes that code for these enzymes tracks the spread of agriculture across Europe from the Middle East, and with it, an increasingly starchy human diet rich in high-carbohydrate staples such as wheat and other grains. Having more copies of a gene usually translates to higher levels of the protein the genes code for -- in this case, the enzyme amylase, which is produced in saliva and the pancreas to break down starch into sugar to fuel the body.

The study, published today (Sept. 4) in the journal Nature, also provides a new method for identifying the causes of diseases that involve genes with multiple copies in the human genome, such as the genes for amylase.

The research was led by Peter Sudmant, assistant professor of integrative biology at the University of California, Berkeley, and Erik Garrison of the University of Tennessee Health Science Center in Memphis.

"If you take a piece of dry pasta and put it in your mouth, eventually it'll get a little bit sweet," Sudmant said. "That's your salivary amylase enzyme breaking the starches down into sugars. That happens in all humans, as well as in other primates."

Chimpanzee, bonobo and Neanderthal genomes all have a single copy of the gene on chromosome 1 that codes for the salivary amylase, referred to as AMY1. The same is true for the two pancreatic amylase genes, AMY2A and AMY2B. These three genes are located close to one another in a region of the primate genome known as the amylase locus.

Human genomes, however, harbor vastly different numbers of each amylase gene.

"Our study found that each copy of the human genome harbors one to 11 copies of AMY1, zero to three copies of AMY2A, and one to four copies of AMY2B," said UC Berkeley postdoctoral fellow Runyang Nicolas Lou, one of five first authors of the paper. "Copy number is correlated with gene expression and protein level and thus the ability to digest starch."

The researchers discovered that, while around 12,000 years ago humans across Europe had an average of about four copies of the salivary amylase gene, that number has increased to about seven. The combined number of copies of the two pancreatic amylase genes also increased by half a gene (0.5) on average over this time in Europe.

Survival advantage of multiple amylase genes

Overall, the incidence of chromosomes with multiple copies of amylase genes (that is, more total copies than chimpanzees and Neanderthals) increased sevenfold over the last 12,000 years, suggesting that this provided a survival advantage for our ancestors.

The researchers also found evidence for an increase in amylase genes in other agricultural populations around the world, and that the region of the chromosomes where these amylase genes are located looks similar in all these populations, no matter what specific starchy plant that culture domesticated. The findings demonstrate that as agriculture arose independently around the world, it seems to have rapidly altered the human genome in nearly identical ways in different populations to deal with increased carbohydrates in the diet.

In fact, the researchers found that the rate of evolution leading to changes in amylase gene copy number was 10,000 times faster than that of single DNA base pair changes in the human genome.

"It has long been hypothesized that the copy number of amylase genes had increased in Europeans since the dawn of agriculture, but we had never been able to sequence this locus fully before. It is extremely repetitive and complex," Sudmant said. "Now, we're finally able to fully capture these structurally complex regions, and with that, investigate the history of selection of the region, the timing of evolution and the diversity across worldwide populations. Now, we can start thinking about associations with human disease."

One suspected association is with tooth decay. Previous studies have suggested that having more copies of AMY1 is associated with more cavities, perhaps because the saliva does a better job of converting starch in chewed food into sugar, which feeds bacteria that eat away at teeth.

The research also provides a method for exploring other areas of the genome -- those involving the immune system, skin pigmentation and the production of mucus, for example -- that have undergone rapid gene duplication in recent human history, Garrison said.

"One of the exciting things we were able to do here is probe both modern and ancient genomes to dissect the history of structural evolution at this locus," he said.

These methods can also be applied to other species. Previous studies have shown that animals that hang out around humans -- dogs, pigs, rats and mice -- have more copies of the amylase gene than their wilder relatives, apparently to take advantage of the food we throw away.

"This is really the frontier, in my opinion," Garrison said. "We can, for the first time, look at all of these regions that we could never look at before, and not just in humans -- other species, too. Human disease studies have really struggled in identifying associations at complex loci, like amylase. Because the mutation rate is so high, traditional association methods can fail. We're really excited how far we can push our new methods to identify new genetic causes of disease."

From hunter-gatherer to agrarian

Scientists have long suspected that humans' ability to digest starch may have increased after our ancestors transitioned from a hunter-gatherer lifestyle to a settled, agricultural lifestyle. This shift was shown to be associated with more copies of the amylase genes in people from societies that domesticated plants.

But the area of the human genome where these copies reside has been difficult to study because traditional sequencing -- so-called short-read sequencing techniques that cut the genome into chunks of about 100 base pairs, sequence the millions of pieces and then reassemble them into a genome -- was unable to distinguish gene copies from one another. Complicating matters, some copies are inverted, that is, they are flipped and read from the opposite strand of DNA.

Long-read sequencing allows scientists to resolve this region, reading DNA sequences thousands of base pairs long to accurately capture repetitive stretches. At the time of the study, the Human Pangenome Reference Consortium (HPRC) had collected long-read sequences of 94 human haploid genomes, which Sudmant and colleagues used to assess the variety of contemporary amylase regions, called haplotypes. The team then assessed the same region in 519 ancient European genomes. The HPRC data helped avoid a common bias in comparative genomic studies, which have used a single, averaged human genome as a reference. The genomes from the HPRC, referred to as a pangenome, provide a more inclusive reference that more accurately captures human diversity.

Joana Rocha, a UC Berkeley postdoctoral fellow and co-first author of the paper, compared the region where amylase genes cluster to what she called "sculptures made of different Lego bricks. Those are the haplotype structures. Previous work had to take down the sculpture first and infer from a pile of bricks what the sculpture may have looked like. Long-read sequencing and pangenomic methods now allow us to directly examine the sculpture and thus offer us unprecedented power to study the evolutionary history and selective impact of different haplotype structures."

Using specially developed mathematical modeling, the researchers identified 28 different haplotype structures among the 94 long-read genomes and thousands of realigned short-read human genomes, all of which cluster into 11 groups, each with a unique combination of AMY1, AMY2A and AMY2B copy numbers.

"These remarkably complex, crazy structures -- regions of gene duplication, inversion and deletion in the human genome -- have evolved independently in different human populations over and over again, even before the rise of agriculture," Sudmant said.

Analysis of the many contemporary human genomes also pointed to an origin 280,000 years ago of an initial duplication event that added two copies of AMY1 to the human genome.

"That particular structure, which is predisposed to high mutation rates, emerged 280,000 years ago, setting the stage for later on, when we developed agriculture, for people who had more copies to have increased fitness, and then for these copy numbers to be selected for," Sudmant said. "Using our methods, for the first time we could really date the initial duplication event."

Alma Halgren, a UC Berkeley graduate student in bioengineering, and Davide Bolognini and Alessandro Raveane of Human Technopole in Milan, Italy, are also first authors of the paper. Other co-authors are Andrea Guarracino of UTHSC, Nicole Soranzo of Human Technopole and the University of Cambridge in the United Kingdom, and Jason Chin of the Foundation for Biological Data Science in Belmont, California. Sudmant's research is funded by the Institute of General Medical Sciences of the U.S. National Institutes of Health (R35GM142916).

Story Source:

Materials provided by University of California - Berkeley. Original written by Robert Sanders. Note: Content may be edited for style and length.


Journal Reference:Davide Bolognini, Alma Halgren, Runyang Nicolas Lou, Alessandro Raveane, Joana L. Rocha, Andrea Guarracino, Nicole Soranzo, Chen-Shan Chin, Erik Garrison, Peter H. Sudmant. Recurrent evolution and selection shape structural diversity at the amylase locus. Nature, 2024; DOI: 10.1038/s41586-024-07911-1


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University of California - Berkeley. "Agriculture accelerated human genome evolution to capture energy from starchy foods." ScienceDaily. ScienceDaily, 4 September 2024. <www.sciencedaily.com/releases/2024/09/240904141503.htm>.

Scientists uncover hidden source of snow melt: Dark brown carbon

Date: September 4, 2024

Source: Washington University in St. Louis  

Summary :Researchers have quantified the effect of dark brown carbon on snow melt.

FULL STORY

Wildfires leave potent climate heaters behind in their wake, particles that enhance the absorption of sunlight and warm the atmosphere. Dropped on snow like a wool poncho, these aerosols darken and decrease the surface reflectance of snowy places.

But it was not yet understood just how different types of smoke particles contribute to these effects.

In a study recently published in npj Climate and Atmospheric Science, researchers at Washington University in St. Louis model how dark-brown carbon (d-BrC) -- light absorbing, water insoluble organic carbon -- from wildfires plays a much larger role as a snow-warming agent than previously recorded.

It's 1.6 times as potent a warmer compared to what researchers previously thought was the main culprit, black carbon.

In the Tibetan Plateau and other midlatitude regions, deposition of water insoluble organic carbon on snow have been previously recorded, "But nobody really looked under the hood to investigate their snow melting potential," said Rajan Chakrabarty, a professor at WashU's McKelvey School of Engineering.

Chakrabarty's PhD student, Ganesh Chelluboyina, a McDonnell International Scholars Academy fellow, and Taveen Kapoor, a postdoctoral fellow, have spent the bulk of their time at WashU taking up that challenge.

The team likens d-BrC to an "evil cousin" of black carbon, and much like black carbon, wildfires deposit it upon snow caps like switching out a white t-shirt for dark brown poncho.

These particles can't be washed away or bleached to the point of losing their absorptivity.

And when the snow loses its reflectivity and warms up, this increases surrounding air temperatures and further notches up the warming cycle.

Without accounting for d-BrC, researchers have likely been underestimating the snow melt from wildfire smoke deposition, and this research will ensure more accurate climate models and measurements.

As massive wildfires become more ubiquitous, policymakers will have to figure out how to mitigate this form of carbon to reduce anomalous snow melt.

Though d-BrC absorbs slightly less light than black carbon, it makes up for it in quantity, being four times more abundant in wildfire plumes compared to BC.

The team plans to further document the real-world effects of d-BrC at work as they enter the experimental phase of research.

How do you do snow-aerosol experiments without going to the field?

In this case, they get a four-foot-tall snow globe for the lab.

"We'll be dropping atomized water droplets into the top of the chamber, creating snow, then deposit aerosols on it," Chelluboyina said.

Story Source:

Materials provided by Washington University in St. Louis. Original written by Leah Shaffer. Note: Content may be edited for style and length.


Journal Reference:Ganesh S. Chelluboyina, Taveen S. Kapoor, Rajan K. Chakrabarty. Dark brown carbon from wildfires: a potent snow radiative forcing agent? npj Climate and Atmospheric Science, 2024; 7 (1) DOI: 10.1038/s41612-024-00738-7


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Washington University in St. Louis. "Scientists uncover hidden source of snow melt: Dark brown carbon." ScienceDaily. ScienceDaily, 4 September 2024. <www.sciencedaily.com/releases/2024/09/240904141501.htm>.

FLORIDA
Aggressive seagrass species discovered in Biscayne Bay

By JoAnn Adkins
September 4, 2024

An invasive species of seagrass has been on a steady march across the world, taking over ecosystems well beyond its native waters of the Red Sea, Persian Gulf and Indian Ocean. Scientists have long wondered when it would reach the waters off the coast of Florida. FIU scientists say that day has arrived.

FIU marine scientist Justin Campbell has positively identified Halophila stipulacea growing in Crandon Marina and nearby areas of Biscayne Bay. It is the first time this non-native species has been found in waters along the continental United States.

“I think this species could pose a considerable threat,” Campbell said. “There are several reports of it being able to outcompete native seagrasses in other areas across the Caribbean. It is plausible that this could also be true for seagrasses here in South Florida.”

A marina worker first noticed the seagrass last month and reached out to Campbell who conducted tests to determine the species. Halophila stipulacea first started spreading its distribution with the opening of the Suez Canal in the late 1800s, hitching rides on the anchors and other parts of boats. By the early 2000s, it was found in the Caribbean.

Healthy seagrass meadows are vital for healthy oceans. They are nursery habitats for commercially and economically important fish as well as shrimp, stone crabs, scallops and other crustaceans and shellfish. Seagrasses are a primary food source for sea turtles, manatees and other marine herbivores. And for the health of the planet, seagrasses are really good at sucking carbon emissions out of the air and storing that carbon long-term. While scientists are still working to understand possible impacts from the invasive species entering waters around the U.S., early research suggests some fish species may avoid the shorter seagrass when scouting nursery locations and local sea turtles in the Caribbean avoid eating the invasive seagrass, preferring native species as part of their regular diets.

While most species of seagrass are on the decline from warming waters and other human-induced impacts, Halophila stipulacea has the unique ability to grow quickly and adapt to different conditions including salinity levels, temperature and light availability. Just a small piece can float through water and grow. Once it settles into soil, it can take hold easily and grow at a variety of depths. While most seagrass species require shallower depths to attain sunlight, Halophila stipulacea has been observed flourishing at depths of 60 feet or more.

“The arrival of yet another invasive species to Florida is a reminder that all of our earth is interconnected and that human actions have the power to change the planet, for good or bad,” said James Fourqurean, co-author of the research and director of the Coastlines and Oceans Division in FIU’s Institute of Environment. Fourqurean has studied seagrasses, especially those in Florida, for more than 40 years. A foremost expert, he is one of the lead scientists in the International Blue Carbon Working Group, as well as scientific representative to the International Blue Carbon Policy Working Group — both dedicated to the recognition and preservation of seagrass meadows, mangroves and tidal salt marshes as critical contributors to slowing the rise of CO2 in the atmosphere.

“Given the importance of seagrasses to a healthy South Florida, we now need to do what we can to limit the spread of this invasive species and be wary of disruptions to the natural order it may cause,” Fourqurean said.

Stipulacea has a very different appearance and structure than the native seagrasses in South Florida and throughout the Caribbean. At least 19 Caribbean islands have reported this seagrass growing in nearby waters and, in some cases, overtaking meadows of native grass.

“We don’t know whether Stipulacea provides similar ecological benefits as compared to our native species,” Campbell said. “Our seagrass meadows here are some of the most pristine and well-protected in the Western Hemisphere. They are iconic and emblematic. We certainly don't want to lose them.”

So how long has this non-native species been in South Florida? It is hard for Campbell to say, but based on the current distribution, he believes it first started taking root several years ago. It had gone unnoticed because, to the casual observer, it can be difficult to distinguish from native vegetation, he said.

Crandon Marina can accommodate medium and large sized sailboats, likely capable of travel to and from areas where Stipulacea is well-established. This is one possible and likely way the non-native seagrass reached Biscayne Bay. With other large marinas in the region, Campbell said surveys and monitoring should be expanded now that this invasive species is confirmed to be in South Florida.

Air pollution linked to decrease in IVF birth rate success

Thursday, 05 September, 2024




Exposure to fine particulate matter (PM) prior to the retrieval of oocytes (eggs) during in vitro fertilisation (IVF) can reduce the odds of achieving a live birth by almost 40%, according to a new study presented at the ESHRE 40th Annual Meeting and published in the journal Human Reproduction.

Conducted over an eight-year period in Perth, Western Australia, the research analysed 3659 frozen embryo transfers from 1836 patients. The median female age was 34.5 years at the time of oocyte retrieval and 36.1 years at the time of frozen embryo transfer. The study examined air pollutant concentrations over four exposure periods prior to oocyte retrieval (24 hours, two weeks, four weeks and three months), with models created to account for co-exposures.

“This is the first study that has used frozen embryo transfer cycles to separately analyse the effects of pollutant exposure during the development of eggs and around the time of embryo transfer and early pregnancy,” said lead author Dr Sebastian Leathersich, from the King Edward Memorial Hospital for Women. “We could therefore evaluate whether pollution was having an effect on the eggs themselves, or on the early stages of pregnancy.”

Analysing PM10 exposure in the two weeks leading up to oocyte collection, the researchers found that the odds of a live birth decreased by 38% when comparing the highest quartile of exposure (18.63 to 35.42 µg/m3) to the lowest quartile (7.08 to 12.92 µg/m3). Increasing PM2.5 exposure in the three months prior to oocyte retrieval was also associated with decreased odds of live birth, falling from 0.90 in the second quartile to 0.66 in the fourth quartile.

Importantly, the negative impact of air pollution was observed despite excellent overall air quality during the study period, with PM10 and PM2.5 levels exceeding WHO guidelines on just 0.4% and 4.5% of the study days, respectively.

“Our results reveal a negative linear association between particulate matter exposure during the two weeks and three months prior to oocyte collection and subsequent live birth rates from those oocytes,” Leathersich said. “This association is independent of the air quality at the time of frozen embryo transfer. These findings suggest that pollution negatively affects the quality of the eggs — not just the early stages of pregnancy, which is a distinction that has not been previously reported.”

Exposure to fine particulate matter through outdoor air pollution is already associated with a range of adverse health conditions, including cardiovascular and respiratory diseases. In 2021, 97% of the urban EU population was exposed to concentrations of PM2.5 above the WHO annual guideline of 5 µg/m3. But although epidemiological data show a clear correlation between pollution and poorer reproductive outcomes, the exact mechanisms remain unclear

“Climate change and pollution remain the greatest threats to human health, and human reproduction is not immune to this,” Leathersich said. “Even in a part of the world with exceptional air quality, where very few days exceed the internationally accepted upper limits for pollution, there is a strong negative correlation between the amount of air pollution and the live birth rate in frozen embryo transfer cycles. Minimising pollutant exposure must be a key public health priority.”

 

Urban Noise Exposure May Aid Prediction of Myocardial Infarction

Findings seen in patients 50 years and younger with fewer traditional risk factors

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By: 

Lori Solomon

Published on: 

Sep 04, 2024, 

WEDNESDAY, Sept 4, 2024 (HealthDay News) -- Young patients with myocardial infarction (MI) and fewer traditional risk factors often have greater exposure to urban noise, according to a study presented at the European Society of Cardiology Congress 2024, held from Aug. 30 to Sept. 2 in London.

Hatim Kerniss, from the Gesundheit Nord Clinic Group in Bremen, Germany, and colleagues explored the impact of noise exposure on the individual risk for early-onset MI. The analysis included 430 consecutive city-dwelling patients (aged 50 years and younger) with acute MI (2015 to 2023).

The researchers observed an elevated incidence of noise exposure among people with MI compared with the general population in the same region. This association was seen for both daytime (65 versus 53 percent) and nighttime (55 versus 41 percent) residential noise exposure. Significantly higher noise exposure was observed in patients with MI and a low LIFE-CVD score (≤2.5 percent) versus those with a high LIFE-CVD score (daytime: 2.32 versus 1.36; nighttime: 1.72 versus 1.00). There was an inverse association between average noise exposure and traditional risk factor exposure, which persisted significantly even after adjusting for potential confounding factors such as socioeconomic status, air pollution exposure, and renal function.

"Including noise exposure in risk prediction models helps accurately identify at-risk individuals, leading to better-targeted prevention," Kerniss said in a statement. "Recognizing noise as a risk factor fills a critical gap and underscores the need for public health strategies to reduce noise pollution, thereby improving cardiovascular health in young populations."

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How Earth's most intense heat wave ever impacted life in Antarctica

Date :September 4, 2024

Source: University of Colorado at Boulder

Summary

:An atmospheric river brought warm, moist air to the coldest and driest corner of the planet in 2022, pushing temperatures 70 degrees above average. A new study reveals what happened to Antarctica's smallest animals.


FULL STORY

Summer 2024 is on track to be the hottest on record for hundreds of cities across the U.S. and globe. Even in Antarctica, during the peak of its winter, extreme heat pushed temperatures in parts of the continent more than 50°F above the July normal.

In a study published on July 31 in the journal Earth's Future, scientists, including researchers at the University of Colorado Boulder, revealed how heat waves, especially those occurring in Antarctica's cold seasons, may impact the animals living there. The research illustrates how extreme weather events intensified by climate change could have profound implications for the continent's fragile ecosystems.

In March 2022, the most intense heat wave ever recorded on Earth hit Antarctica, just as organisms in the southern region braced themselves for the long, harsh winter ahead. The extreme weather raised temperatures in parts of Antarctica to more than 70°F above average, melting glaciers and snow even in the McMurdo Dry Valleys, one of the planet's coldest and driest regions.

As part of a Long-Term Ecological Research (LTER) project in Antarctica, the research team found that the unexpected melt followed by a rapid refreeze likely disrupted the life cycles of many organisms and killed a large swath of some invertebrates in the McMurdo Dry Valleys.

"It's important that we pay attention to these signals, even if they're coming from microscopic organisms in soils in a polar desert," said Michael Gooseff, the paper's senior author and professor in the Department of Civil, Environment and Architectural Engineering at CU Boulder. "They're the early responders to changes that could cascade up to larger organisms, the landscape and even us, far away from Antarctica."

When Gooseff arrived in Antarctica in November 2021, the continent looked much like it had for the past two decades. As a fellow of the Institute of Arctic and Alpine Research (INSTAAR), Gooseff has led the LTER at the McMurdo Dry Valleys, a National Science Foundation-funded project, for the past decade. Nearly every Antarctic summer, he travels to the southern region to study its ecosystem and how organisms survive in extreme environmental conditions.

While most animals can't tolerate the region's dryness and cold, some microbes and invertebrates, including roundworms and water bears, thrive in this frozen desert. Water bears, or tardigrades, are tiny, eight-legged animals measuring 0.002 to 0.05 inches long. They can survive extreme conditions -- as cold as -328°F and as hot as 300 °F -- that would kill most other forms of life.

In 2022, all members of the polar expedition team left the continent in February, before the Antarctic summer ended. A month later, Antarctica experienced the most extreme heat wave on record, driven by an intense storm known as an atmospheric river, which transported moist air over long distances to the polar region.

The team's sensors in the McMurdo Dry Valleys recorded air temperatures, which typically hover around -4°F in March, rising above freezing and exceeding the average by 45°F.

Satellite imagery and stream discharge measurements showed that the sudden warming wetted the valleys' soil more than two months after the peak summer thaw, at a time when the land is typically dry.

In two days, after the heat wave passed, temperatures plummeted and the soil froze. This event happened during a critical transition period, when organisms hunker down and get ready for the dark, cold winter. Gooseff and his colleagues were curious about how animals in the valleys responded.

"These animals invest a significant amount of energy in preparing and shutting down for the winter," said Gooseff. "When things start to warm up the following summer, they use energy to become active again. One of our major concerns with unusual weather events like this heat wave is that these animals might start using a lot more energy, thinking it's summer, only to have to shut down again two days later. How many times can they go through that cycle before they exhaust their energy reserves?"

He and the team returned to Antarctica the following summer, in December 2022. They sampled the soil and compared organisms living in areas that became wet to those that stayed dry during the heat wave.

They observed a 50% decrease in the population of Scottnema, a common roundworm, in areas that got wet. Scottnema is adapted to extremely cold and dry climates.

"The heat wave made the environment appear warm enough for things to get wet, creating a false start to summer. Some of the biology responding to these temperatures might be seriously disrupted by this," Gooseff said.

Rapid swings between extremes in weather can disproportionately impact sensitive species like Scottnema, but they may have far less impact on other animals, such as tardigrades. These creatures have a higher tolerance for moisture, allowing them to proliferate as the environment becomes wetter.

"Changes in which species are in the soil and how big the populations are can have a major impact on the ecosystem's food web and nutrient cycling," Gooseff said.

Previous research has shown Scottnema is responsible for about 10% of the carbon processed in the Dry Valleys' soil ecosystem.

As climate change exacerbates extreme weather events in Antarctica, larger species are also being impacted. For example, in the summer of 2013, an unusual rainfall event along the Adélie Coast of East Antarctica killed all Adélie penguin chicks in the region. In July, temperatures in parts of East Antarctica climbed up to 50 °F above the usual winter average.

Gooseff and his team plan to continue documenting extreme weather events and their impacts on the Antarctic ecosystem.

What happens in Antarctica doesn't stay in Antarctica, Gooseff said.

"The loss of ice shelves has pretty dramatic impacts on the mass balance of our oceans, and it affects us even thousands of miles away."

Story Source:

Materials provided by University of Colorado at Boulder. Original written by Yvaine Ye. Note: Content may be edited for style and length.

Related Multimedia:The McMurdo Dry Valleys in Antarctica

Journal Reference:J. E. Barrett, Byron J. Adams, Peter T. Doran, Hilary A. Dugan, Krista F. Myers, Mark R. Salvatore, Sarah N. Power, Meredith D. Snyder, Anna T. Wright, Michael N. Gooseff. Response of a Terrestrial Polar Ecosystem to the March 2022 Antarctic Weather Anomaly. Earth's Future, 2024; 12 (8) DOI: 10.1029/2023EF004306


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University of Colorado at Boulder. "How Earth's most intense heat wave ever impacted life in Antarctica." ScienceDaily. ScienceDaily, 4 September 2024. <www.sciencedaily.com/releases/2024/09/240904141509.htm>.

AUSTRALIA

Birth of new Gilbert's potoroos on Middle Island celebrated by researchers

By Byron Queale and Peter Barr
ABC Esperance


Two new Gilbert's potoroos were spotted by researchers in August. (Supplied: DBCA)

In short:

Two new Gilbert's potoroos have been born in a protected population on Middle Island, off WA's southern coast.

The marsupial is one of Australia's rarest and most endangered, with as few as 120 remaining in the wild.

What's next?

Efforts are underway to see if the island can play host to other threatened native species.
abc.net.au/news/gilberts-potoroo-population-recovering-middle-island-southern-wa

A population of one of Australia's rarest and most endangered marsupials is slowly recovering off Australia's southern coast.

Middle Island, 820 kilometres south-east of Perth in the Recherche Archipelago, is home to a population of tiny Gilbert's potoroos.

Originally thought to be extinct, the animals were rediscovered at Two People's Bay, near Albany, in 1994.

A Gilbert's potoroo in its native habitat near Albany. (Supplied: Dick Walker/file photo)

With the estimated global population as low as 120, conservation and relocation efforts have been stepped up in recent years.

10 potoroos were relocated to the island in a bid to preserve the population in 2018, three years after a bushfire ripped through the local habitat at Two People's Bay.


There are only about 120 Gilbert's potoroo left in the wild. (Supplied: DBCA)
Monitoring trip sparks good news

During a recent monitoring trip, researchers spotted something positive on their camera traps — two new potoroos.

"It's exciting … they were really healthy animals," Department of Biodiversity, Conservation and Attractions (DBCA) ecologist Sarah Comer said.

"And the female that we caught actually had a little pouch young.


"There's plenty of reasons to be optimistic about their future"


Middle Island is located on the South Coast of Western Australia. (Supplied: DBCA)

In early August, teams from DBCA, Esperance Tjaltjraak Native Title Aboriginal Corporation, and the Odonata Foundation spent five days on Middle Island to monitor the health of the potoroo population.

"We were over there trying to trap animals to see whether we had new recruits [and] what sort of health they were in," Ms Comer said.


Researchers examine one of the potoroos. (Supplied: DBCA/Sarah Comer)
Perfect home after long battle

She said Middle Island was the perfect place for the potoroo to thrive.

"Its size … made it quite attractive," Ms Comer said.


"The other really attractive thing about the island is there's no feral cats or foxes there, and so we can actually put animals out there without the invasive predators impacting them."

Jackie Courtenay has been working with the marsupials for nearly three decades.

"There was the work that was done initially, just trying to find more animals," she said.

"Seeing if they occurred anywhere else other than Two People's Bay, where they were originally rediscovered."


A Gilbert's potoroo with a baby. (Supplied: DPAW/file photo)

While the 2015 bushfire at Two People's Bay was a setback, there's now hope the island can play host to other endangered species.

Ms Comer said surveys were underway on Middle Island's suitability to host a population of noisy scrub birds.

Thirteen camera traps and continued monitoring will now help determine the location's role in future conservation efforts.

Israel's Netanyahu demands open-ended control of Gaza's border with Egypt

The question of Israeli control of the Philadelphi corridor — a narrow strip of land along Gaza’s border with Egypt, seized by IDF troops in May — has become a central obstacle in cease-fire talks.


Photo by: Getty Images
Israeli Prime Minister Benjamin Netanyahu.

By: AP via Scripps News

Israeli Prime Minister Benjamin Netanyahu said Wednesday that Israel must keep open-ended control of Gaza’s border with Egypt, digging in on his stance on an issue that has threatened to derail cease-fire efforts.

Netanyahu’s comments came as the United States is developing a new proposal for a cease-fire and hostage release, hoping to break a long deadlock and bring an end to the nearly 11-month-old war.

The question of Israeli control of the Philadelphi corridor — a narrow strip of land along Gaza’s border with Egypt, seized by troops in May — has become a central obstacle in the talks. Hamas has demanded an eventual full Israeli withdrawal from Gaza in the multi-phase truce deal.

Egypt, a mediator in the talks along with the U.S. and Qatar, has also demanded a concrete timeline for Israeli troops to leave the Philadelphi corridor. And on Wednesday, the United Arab Emirates, which established formal ties with Israel in the 2020 Abraham Accords, also criticized the Israeli stance.

Speaking to foreign journalists, Netanyahu repeated his stance that Israel must maintain its hold on the border to prevent Hamas from rearming by smuggling weapons into Gaza. He said it was a vital part of the war goal of ensuring Hamas cannot repeat its Oct. 7 attack on Israel.

“Gaza must be demilitarized, and this can only happen if the Philadelphi corridor remains under firm control,” he said, claiming Israeli troops had discovered dozens of tunnels under the border.

He said Israel would only consider withdrawing from the corridor when presented with an alternative force to police it.

“Bring me anyone who will actually show us … that they can actually prevent the recurrence” of smuggling, he said. “I don’t see that happening right now. And until that happens, we’re there.”

Families of remaining hostages have stepped up their demands that he agree to a deal after Hamas killed six hostages last week as Israeli troops appeared to be moving to rescue them. In angry public statements, hostage families have accused Netanyahu of blocking a deal and potentially sacrificing their loved ones’ lives for the sake of holding the border strip. Hundreds of thousands of Israelis have taken to the streets in recent days, calling for a deal and saying time is running out to bring home the hostages alive.


Netanyahu pushed back against the pressure, saying his stance was necessary to “ensure Hamas doesn’t pose a threat to Israel.”

“I can understand the torment of families,” he said. “But the responsibility of leaders is not merely to share the sentiment, the emotion, but also to exercise judgment."

Asked by journalists for a timeline on ending the war, he refused to give one. “How long can we do this? As long as it takes to achieve this victory. And I think we’re getting a lot closer,” he said.

Netanyahu repeatedly insisted holding the border would also pressure Hamas to release hostages. At one point, he erroneously claimed the invasion of Rafah in May forced Hamas’ first release of hostages — which had actually taken place months earlier in November under a weeklong cease-fire deal. He then said the deal was “the result of our invasion, the military pressure we put on them.”

Netanyahu, Israeli public at odds over Gaza hostage deal

The Israeli leader believes keeping hold of the Philadelphi corridor is essential for Israel's security. In a recent poll, a slight majority of Israelis see bringing the hostages home as more important.

https://p.dw.com/p/4kHeT

Israeli Prime Minister Benjamin Netanyahu held a press conference Wednesday in English to foreign press, clarifying his position regarding negotiations on a deal with Hamas that aims to secure a cease-fire in Gaza. He also addressed the return of the Israeli hostages held by the militant Islamist group.

Netanyahu accused Hamas of rejecting all elements of a proposal for a cease-fire in Gaza that would lead to the release of hostages.

"Hamas has rejected everything... I hope that changes because I want those hostages out," Netanyahu said. "We're trying to find some area to begin the negotiations."

But a report published by Israeli newspaper Yedioth Ahronoth — citing a document it said it obtained — shows that Netanyahu relayed a list of new demands in late July to international mediators.

The new conditions were reportedly added at the very last minute before talks on a cease-fire were due to begin. These were added to a set of demands Netanyahu had made in late May, according to the report.
Netanyahu doubles down on control of Philadelphi corridor

The focal point of the current negotiations to end nearly 11 months of war is the so-called Philadelphi corridor, the border area between the Gaza Strip, Egypt and Israel.

Netanyahu said that if the Israel Defense Forces (IDF) were to leave the corridor, it would mean giving in to Hamas' demands. The prime minister insisted that he is not willing to give up on the Israeli presence there. Israel, the US, Germany, the EU and others designate Hamas as a terrorist organization.

For its part, Hamas has demanded a complete Israeli withdrawal from the area as part of the stalled talks mediated by the United States, Qatar and Egypt.

Israeli media reports suggest the country would be willing to leave the Philadelphi corridor as part of a multi-phase truce deal, with the condition that it happen in the second phase of the deal, whereas Hamas wants it to happen in the first phase.

Many Israelis back Philadelphi withdrawal

The Israeli prime minister said that leaving the corridor would mean reducing the pressure on Hamas, adding that the Israeli presence in the corridor will not end until a mechanism is found to make sure the region does not become a way for Hamas to rearm by smuggling weapons into the Gaza Strip.

"Bring me anyone who will actually show us ... that they can actually prevent the recurrence" of smuggling, he said. "I don't see that happening right now. And until that happens, we're there."

Support for Netanyahu's plans to keep Israel's presence at the corridor appeared to have waned. An opinion poll by Israeli public broadcaster Kan showed the Israeli public at odds with the prime minister's views.

According to the poll, some 53% of the public believes Israel should leave the corridor if it would deliver a deal to bring the hostages home, and 29% said they think Israel should keep its presence there even at the cost of not reaching a deal.

The Philadelphi corridor is the border between the Gaza Strip and EgyptImage: Khalil Hamra/AP Photo/picture alliance

The same poll also showed that Israelis' trust in Netanyahu and his defense minister, Yoav Galant, in running the war has diminished.

Some 61% of those polled said they do not trust Netanyahu in managing the war in Gaza, while 50% said similarly of Galant.

Anger over the safety of hostages

Netanyahu said maintaining pressure on Hamas was the best way to return the 101 hostages still remaining in Gaza.

"You need to squeeze them, to put pressure on them to release the remaining hostages. So if you want to release the hostages, you've got to control the Philadelphi corridor," he said.

But the families of many hostages, including those of some of the six whose bodies were recovered from a tunnel in southern Gaza on Sunday, have accused Netanyahu of sacrificing their loved ones in order to keep Israeli troops in the corridor.

Israelis have been calling for their government to secure a deal that would bring the hostages homeImage: Mostafa Alkharouf/Anadolu/picture alliance

After the bodies of six Israeli hostages were found in Rafah, with the Israeli Health Ministry saying they were all shot, Israel has seen a wave of protests calling for the government to sign a deal with Hamas.

Many protesters blame Netanyahu for not reaching a deal for purely political reasons. They accuse him of prioritizing the survival of his own coalition, for which he is dependent on far-right politicians such as Itamar Ben-Gvir and Bezalel Smotrich, who vehemently object to a cease-fire that they call a "reckless deal."

In his press conference to Israeli media in Hebrew, Netanyahu rejected those claims.

DW

ft/jcg (Reuters, AP)

Israeli Protesters Have Chosen a Side


Fearing for the remaining captives, the mass rallies that erupted across Israel were essentially demanding an end to the war—and Netanyahu knows it.

Israeli Prime Minister Benjamin Netanyahu, the mass protests that erupted across Israel on Sunday were all about overthrowing him and his government. Certainly, this goal was stated explicitly by almost every speaker who took to the stage at the main protest in Tel Aviv—where reportedly more than 300,000 Israelis flooded the streets after the army’s recovery of the bodies of six more hostages from Gaza, who had been executed shortly beforehand. Einav Zangauker, the mother of the hostage Matan, captured the mood of much of the public when she ordained Netanyahu with a new nickname: “The executioner.”

But the protests, which have continued into the week, also had a deeper, more subversive message that Netanyahu probably understood too. Without any of the speakers explicitly saying as much, Sunday’s demonstrations were for an end to the war.This article was published in partnership with +972 Magazine. A version was first published in Hebrew on Local Call.

To be clear, such a statement was not uttered from the stage. Nor was it seen on many placards, save for among the small pockets of left-wing protesters that formed the anti-occupation bloc. On the whole, opposition to the continuation of the war does not stem from moral concerns: There was no mention whatsoever of Israel’s genocidal actions in Gaza, nor was there a call for reconciliation or peace with the Palestinians. Rather, the protesters are preoccupied first and foremost with their fellow citizens held in Gaza, and demanding a “Deal Now” that would result in their release. Still, these calls have far-reaching significance.

Even in the event of a temporary ceasefire that would facilitate an initial hostage-prisoner exchange, such as the one envisaged by the deal currently on the table, Netanyahu is likely concerned that it would be extremely difficult to renew the war effort once the army has already withdrawn from the Philadelphi and Netzarim corridors and hundreds of thousands of Palestinians have been allowed to return to northern Gaza. Israeli society is exhausted; reservists are increasingly dodging their draft orders; Hamas is far from defeated; and by the end of the year, it will be difficult to re-instill the spirit of mobilization and the will to fight that was so strong immediately after October 7. As such, Netanyahu fears, even a short-term ceasefire would soon turn into a permanent one.

Israeli society has always been highly militaristic, with a strong tendency to rally behind the army in times of war. A mass anti-war demonstration while a war is still raging is thus an extraordinary event. The only parallel that comes to mind is the “demonstration of the 400,000” after the Sabra and Shatila massacre in 1982; yet even then the emphasis was more on the immoral way in which the war was being waged, rather than a protest against the war as a whole.

Netanyahu was probably aiming to stir up this militarism when he declared that Israeli troops must remain in the Philadelphi Corridor, even at the expense of a hostage deal. After all, it is hard to conceive of a goal more suited to the security discourse than cutting off Hamas’s “oxygen route,” through which it supposedly smuggles weapons into Gaza. But that argument didn’t satisfy the hundreds of thousands who protested on Sunday night.

Even on Saturday evening, before the bodies of the six hostages were recovered, Danny Elgarat, whose brother is still being held captive in Gaza, asserted: “You [Netanyahu] turned the Philadelphi Corridor into the mass grave of the hostages.” On Sunday evening, such messages were even stronger, and the audience cheered for them without reservation.

Many prominent figures on the Israeli right, from Netanyahu himself to the commentator Amit Segal, sought to redirect the public’s anger toward Hamas for executing six defenseless hostages, and away from Netanyahu and his government. But even this argument, which just a few days ago would have rallied a consensus in favor of “destroying Hamas,” no longer resonated.

“Netanyahu says that whoever murders hostages doesn’t want a deal,” Ilana Gritzewsky, a freed hostage and the wife of Matan Zangauker who is still being held in Gaza, said at the rally on Sunday. “But he keeps putting spokes in the wheels and refusing the deal. He’s murdering the hostages.”

Consciously or not, the hundreds of thousands who flooded the streets were an antidote to the poisonous security discourse that has been injected into Israeli society for the past 11 months. They don’t buy the talk of a “total victory” over Hamas, nor do they buy the claim—marketed as an iron truth by politicians and journalists of all inclinations—that “only military pressure will free the hostages.” The bodies of Hersh, Eden, Ori, Alex, Carmel, and Almog were the conclusive proof of the futility of such an argument.

Most importantly, they do not believe that the cessation of the war, at least at this stage, is a threat to their existence, contrary to what Netanyahu and his spokespeople have been claiming since the first days of the fighting. Quite the opposite: They perceive the continuation of the war as a direct threat to the lives of the hostages and, to a certain extent, their own. This is the subversive meaning of the call for a “Deal Now,” even if not everyone who voiced it understood its implication.
A Choice Between “Deal Now” and “Sacrifice Now”

The Israeli right still argues that it is not the Philadelphi Corridor that stands in the way of a deal but rather Hamas leader Yahya Sinwar and his impossible conditions. Most senior Israeli security analysts now reject this argument, insisting instead that it is the conditions set by Netanyahu, under pressure from Bezalel Smotrich and other on the far right of his government, that are sabotaging the agreement—even after Hamas surprised Israel by accepting a proposal that Israel itself had submitted.

But even if we accept the right’s narrative that Sinwar is the one preventing a deal, this is not what lies at the root of the dispute between those who see the Philadelphi Corridor as the bedrock of our existence and those who are willing to give it up. By voting in favor of Netanyahu’s proposal to keep hold of the Philadelphi Corridor, those cabinet members are saying that the death of the hostages, however painful and regrettable it may be, is a price that must be paid in pursuit of “total victory” over the enemy.

For Ben-Gvir and Smotrich, who suggested on October 7 “not to give the hostages significant consideration,” this victory means the elimination of Palestinians from the equation altogether: the erasure of their cities, and the expulsion of all or most of the Palestinian population living between the Jordan River and the Mediterranean Sea. For Netanyahu, it is not always clear whether “total victory” means his life’s mission of ensuring Jewish-Israeli dominance and preventing Palestinian independence, or simply his own political survival. Some would likely also be satisfied with Hamas’s surrender, and believe that this is still possible.

Ultimately, it comes down to a choice which is now abundantly, if belatedly, clear to all: continue the war indefinitely and endanger the lives of the hostages, or end the war in order to free them. The Israeli right chooses the former, while the hundreds of thousands taking to the streets don’t think any war goals are worth the blood of the hostages.

We saw similar numbers of protesters on the streets for much of last year, amid the controversy surrounding the government’s judicial overhaul. But that, at least, was still about laws, which can always change. Here we are talking about human lives: the sons, daughters, mothers, and fathers still being held in Hamas’s tunnels in Gaza.

In this sense, the recovery of the bodies of the six hostages casts serious doubt on the question of whether it is possible to speak of “Israeli society”—Jewish-Israeli, of course—as a cohesive body. The processes of disintegration and alienation are long-standing, and they gained momentum in the face of the judicial overhaul and the fierce struggle against it. Now, however, it is hard to see what connects those who are willing to sacrifice the hostages and those who see it as a crime or even a sin.

But while the “Sacrifice Now” camp has a clear plan for the future—a long-standing war and the transformation of Israel into a kind of modern Sparta—the “Deal Now” camp has no alternative vision, one where Israel could manage its relations with the Palestinians in any way other than violent confrontation. It is even careful not to call openly or decisively for a ceasefire or an end to the war, though that would be the fairly certain outcome of any such deal. The lack of such a vision and shared principles makes it very difficult to form a united front that could effect political change.

Many protesters returned home on Sunday with the feeling that, despite their impressive show of force, the chances of forcing the government to change course are slim. Indeed, under the current government, Israel increasingly resembles a dictatorial regime even with regard to its Jewish citizens, in which rulers do not need broad social support to govern; it is enough for them to rule by force, deploying the army against Palestinians and the police against Israeli citizens.

Netanyahu’s news conference on Monday night strengthened this impression. Instead of showing any modicum of compassion to the masses who took to the streets the night before in agony and despair, he described those opposing his decision to remain in the Philadelphi Corridor—including his defense minister, Yoav Gallant, and the top brass in the army and security services—as helping Hamas. He vowed to remain in the Philadelphi Corridor practically forever, effectively blocking any chance for a ceasefire deal.

Still, we shouldn’t underestimate the subversive message that Sunday’s demonstrations and those that followed conveyed. During a raging war, they called for its cessation. In the face of a militaristic propaganda machine, they presented civil discourse. In the face of a government willing to sacrifice the hostages, they demonstrated a deeper social and national solidarity.

At this stage, it is difficult to foresee whether this broad mobilization will lead to political change; that will depend on many components unrelated to the protest movement, including American pressure. The challenge is enormous, immensely greater than the one facing the protest movements on Jerusalem’s Balfour Street in 2020 or Tel Aviv’s Kaplan Street in 2023: not only toppling a government and thwarting its legislative project but stopping the longest and bloodiest war in the history of the Israeli-Palestinian conflict. But a mass refusal to accept the narrative being fed from on high is an important first step—and that is exactly what we’re now seeing.