Category - Science

Farming Had an Earlier Start, a Study Says

New York Times, By Sindya H. Bhanoo, July 27

Farming may have originated 23,000 years ago, thousands of years earlier than previously thought, according to a new study.

Researchers discovered a large number of seeds at an ancient hunter-gatherer site known as Ohalo II on the shore of the Sea of Galilee in Israel. Many of the seeds had scars, a mark that distinguishes domesticated species from wild forms.

Additionally, about 150,000 plant remains were retrieved from the site, comprising more than 140 species. The mix included 13 known weeds, as well as edible cereals like wild emmer, barley and oats.

Mammoths killed by abrupt climate change

Science Daily, July 23

New research has revealed abrupt warming, that closely resembles the rapid human-made warming occurring today, has repeatedly played a key role in mass extinction events of large animals, the megafauna, in Earth’s past.

Using advances in analysing ancient DNA, radiocarbon dating and other geologic records an international team led by researchers from the University of Adelaide and the University of New South Wales (Australia) have revealed that short, rapid warming events, known as interstadials, recorded during the last ice age or Pleistocene (60,000-12,000 years ago) coincided with major extinction events even before the appearance of man.

Published today in Science, the researchers say by contrast, extreme cold periods, such as the last glacial maximum, do not appear to correspond with these extinctions.

“This abrupt warming had a profound impact on climate that caused marked shifts in global rainfall and vegetation patterns,” said University of Adelaide lead author and Director of the Australian Centre for Ancient DNA, Professor Alan Cooper.

Amazonians’ ancient links to Indigenous Australians

Sydney Morning Herald, By Bianca Hall, July 22

Distant DNA links have been discovered between Aboriginal Australians and tribes living deep within the Amazon rainforest.

Researchers in the US and Denmark have established that people sharing DNA links with Aboriginal people crossed the Bering land bridge between Siberia and the Americas thousands of years ago.

The revelations, published in Nature and Science Magazine, are the strongest signs yet that there could have been multiple migrations from Siberia to the Americas tens of thousands of years ago.

The findings have captivated the international science community, with Jennifer Raff, an anthropological geneticist at the University of Texas, telling Nature on Tuesday they were, “honestly one of the most exciting results we’ve seen in a while.”

The world’s most famous climate scientist just outlined an alarming scenario for our planet’s future

Washington Post, By Chris Mooney, July 20

James Hansen has often been out ahead of his scientific colleagues.

With his 1988 congressional testimony, the then-NASA scientist is credited with putting the global warming issue on the map by saying that a warming trend had already begun. “It is time to stop waffling so much and say that the evidence is pretty strong that the greenhouse effect is here,” Hansen famously testified.

Now Hansen — who retired in 2013 from his NASA post, and is currently an adjunct professor at Columbia University’s Earth Institute — is publishing what he says may be his most important paper. Along with 16 other researchers — including leading experts on the Greenland and Antarctic ice sheets — he has authored a lengthy study outlining an scenario of potentially rapid sea level rise combined with more intense storm systems.

It’s an alarming picture of where the planet could be headed — and hard to ignore, given its author. But it may also meet with considerable skepticism in the broader scientific community, given that its scenarios of sea level rise occur more rapidly than those ratified by the United Nations’ Intergovernmental Panel on Climate Change in its latest assessment of the state of climate science, published in 2013.

The authors conclude that 2 degrees Celsius global warming—the widely accepted international target for how much the world should limit global warming—is “highly dangerous.”

Climate Progress: Climate Scientist Warns Sea Levels Are Rising Faster Than We Thought

Warming of oceans due to climate change is unstoppable, say US scientists

The Guardian, By Suzanne Goldenberg, July 16

The warming of the oceans due to climate change is now unstoppable after record temperatures last year, bringing additional sea-level rise, and raising the risks of severe storms, US government climate scientists said on Thursday.

The annual State of the Climate in 2014 report [Document of Inordinate Size], based on research from 413 scientists from 58 countries, found record warming on the surface and upper levels of the oceans, especially in the North Pacific, in line with earlier findings of 2014 as the hottest year on record.

Global sea-level also reached a record high, with the expansion of those warming waters, keeping pace with the 3.2 ± 0.4 mm per year trend in sea level growth over the past two decades, the report said.

Scientists said the consequences of those warmer ocean temperatures would be felt for centuries to come – even if there were immediate efforts to cut the carbon emissions fuelling changes in the oceans.

Large Hadron Collider Discovers Long-Elusive ‘Pentaquark’ Particle

ABC, By Alyssa Newcomb, July 14

The world’s largest atom smasher has made a discovery that was five decades in the making.

Scientists with the European Organization for Nuclear Research (better known by its French acronym CERN) today announced the detection of a new kind of subatomic particle called the pentaquark, which essentially means a new form of matter has been discovered. The findings have now been submitted to the journal Physical Review Letters [arxiv].

The pentaquark was first predicted in the 1960s but actual detection of the particle had eluded scientists for decades. A quark is the term for the building blocks that make up hadrons. (Protons and neutrons are among the best known hadrons.)

Before the discovery of five quarks bound together in a hadron, only hadrons with two or three quarks were known to exist, along with evidence of some subatomic particles made of four quarks.

“Every particle we’re aware of, except for a few oddballs, is made up of quark and anti-quark, or three quarks. That’s what builds up the mass of the universe, what makes you and me and the Earth and the sun,” Eric Swanson, a theoretical physicist at the University of Pittsburgh, told the Associated Press. “This, if verified, should be the beginning of a whole new form of matter.”

Extreme Tech: CERN’s Large Hadron Collider confirms newest particle: the pentaquark
BBC: Large Hadron Collider discovers new pentaquark particle
Wikipedia: Pentaquark

Commonly prescribed drugs affect decisions to harm oneself and others

Medical Express, July 2

Healthy people given the serotonin-enhancing antidepressant citalopram were willing to pay almost twice as much to prevent harm to themselves or others than those given placebo drugs in a moral decision-making experiment at UCL. In contrast, the dopamine-boosting Parkinson’s drug levodopa made healthy people more selfish, eliminating an altruistic tendency to prefer harming themselves over others. The study was a double-blind randomised controlled trial and the results are published in Current Biology.

The research provides insight into the neural basis of clinical disorders characterized by a lack of concern for others, such as psychopathy. Serotonin and dopamine levels have both been linked to aggressive and antisocial behavior, and this study helps explain why.

“Our findings have implications for potential lines of treatment for antisocial behavior, as they help us to understand how serotonin and dopamine affect people’s willingness to harm others for personal gain,” says lead author Dr Molly Crockett, who conducted the study at UCL and is now at Oxford University. “We have shown that commonly-prescribed psychiatric drugs influence moral decisions in healthy people, raising important ethical questions about the use of such drugs.

Poppy yields the final secret to making morphine

Determining the last unknown step in the opiate chemical pathway came down to a single gene.

Science News, By Bethany Brookshire, June 25

The final puzzle piece in the chemical pathway that makes morphine has been identified, scientists report June 25 in Science. The work fills in the center piece in the path — the protein converting the compound (S)-reticuline to (R)-reticuline.

By analyzing poppy DNA and confirming its function in yeast, the researchers showed that a single gene produces an enzyme made of two parts, each of which controls a step of the conversion of reticuline.

This protein links the previously known beginning and end steps in the morphine-making pathway. Both the beginning and end steps have already been engineered in separate yeast strains. Putting the three parts of the pathway together will eventually result in yeast that produce morphine.

And maybe, just maybe, some really incredible poppy rolls.

Earth’s sixth mass extinction has begun, new study confirms

The Conversation, By James Dyke, June 19

We are currently witnessing the start of a mass extinction event the likes of which have not been seen on Earth for at least 65 million years. This is the alarming finding of a new study published in the journal Science Advances.

The research was designed to determine how human actions over the past 500 years have affected the extinction rates of vertebrates: mammals, fish, birds, reptiles and amphibians. It found a clear signal of elevated species loss which has markedly accelerated over the past couple of hundred years, such that life on Earth is embarking on its sixth greatest extinction event in its 3.5 billion year history.

This latest research was conducted by an international team lead by Gerardo Ceballos of the National Autonomous University of Mexico. Measuring extinction rates is notoriously hard. Recently I reported on some of the fiendishly clever ways such rates have been estimated. These studies are producing profoundly worrying results.

Scientists say Earth’s groundwater being drained at rapid rate

Scientists warned the situation would only worsen with climate change and population growth

AFP, June 17

Washington – Human activity is leading to the rapid draining of about one third of the planet’s largest underground water reserves and it is unclear how much fluid remains in them, two new studies have found.

Consequently, huge sections of the population are using up groundwater without knowing when it will run out, researchers said in findings that will appear in the journal Water Resources Research and were posted online on Tuesday.

“Available physical and chemical measurements are simply insufficient,” University of California Irvine professor and principal investigator Jay Famiglietti said in a statement.

[…]

Researchers found that the Arabian Aquifer System, providing water for more than 60 million people, is the world’s most overstressed source.

The Indus Basin aquifer of northwestern India and Pakistan is the second-most overstressed, and the Murzuk-Djado Basin in northern Africa is third, scientists said.

In drought-striken California, the Central Valley aquifer was labeled as “highly stressed.”

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