Archive for Science

DNA shows no trace of contact between ancient Easter Islanders and South America

From ABC Science, Friday 13 October 2017:

Mystery and intrigue surrounds the life and times of people who created the famous Moai statues on Rapa Nui off the coast of Chile — and a new study suggests they were more isolated than previously thought.

While it is widely accepted that the remote island, dubbed Easter Island by Dutch explorers, was first settled by Polynesians before 1200 AD, scientists have long debated about what happened next.

One of the big questions is whether or not the early islanders had any contact with Indigenous South Americans.

A 2014 DNA study of present-day Rapa Nui and archaeological evidence from sweet potato crops suggested the islanders mixed with native Americans before Europeans arrived in 1722 AD.

But now a new study of ancient DNA, published in the journal Current Biology, indicates the two groups did not intermingle at all before European settlement. Read more.

Australian trapdoor spider may be a seafaring castaway from Africa

From ABC News in Science, 3 August 2017:

Trapdoor spiders are reluctant travellers, but millions of years ago one species appears to have made an epic journey from Africa across the vast Indian Ocean to call Australia home.

The Australian trapdoor spider — Moggridgea rainbowi — which is found on Kangaroo Island is famously provincial, rarely moving more than a few metres away from its birthplace for its entire life.

But a study of the spider’s genome, published today in PLOS One, shows it split away from its closest relatives in Africa between 2 and 16 million years ago. Read more.

Molecule found in Titan’s atmosphere may form cell-like membranes

From ABC News in Science, 29 July 2017

A compound that may form cell wall-like structures has been detected in the dense atmosphere of Saturn’s moon Titan.

The discovery, reported today in Science Advances, was made using the highly sensitive Atacama Large Millimeter Array radio telescope in Chile.

Saturn’s largest moon has long been considered an ideal candidate for organic life elsewhere in our galaxy, said the study’s lead author, Maureen Palmer from the NASA Goddard Space Flight Center.

“In some ways Titan is sort of Earth-like,” Ms Palmer said.

The moon’s atmosphere is around 95 per cent nitrogen, and there are lakes and seas on its surface. But unlike Earth, these lakes and seas contain liquid methane rather than water. Read more.

Einstein’s ‘impossible’ hope: Light bending theory directly observed in distant stars for first time

From ABC Science, 8 June 2017:

Astronomers have used the gravitational warping of light, predicted by Einstein nearly a century ago, to measure the mass of a distant star for the first time.

The team, led by Kailash Sahu of the Space Telescope Science Institute in Baltimore, measured the mass of a white dwarf star called Stein 2051 B as it passed in front of another more distant star — an event Einstein thought would be impossible to observe.

The findings, publishing in today’s edition of Science, will help us understand more about these small dense stars and the ultimate fate of our Sun, which will become a white dwarf star when it burns out.

Dr Sahu relied on Einstein’s idea that the gravity of an object can bend and magnify rays of light.

According to Einstein’s general theory of relativity, an object passing in front of another bright object would bend the light of the more distant object and cause it to appear to move from its original position.

In this “gravitational lensing”, the distance apparently travelled by the background object depends on the mass of the object in front, which is curving the light. Read more.

Who were the ancient Egyptians? Mummy DNA reveals surprising clues

From ABC Science, 31 May 2017:

Mummies from ancient Egypt have revealed another secret — some of them share very little of the sub-Saharan African ancestry that dominates the genetic heritage of modern Egyptians.

The discovery, published today in Nature Communications, suggests the African heritage evident in modern Egyptian populations may have been the result of the slave trade down the Nile in the past 1,500 years.

Researchers used modern genetic analysis techniques to study the genomes of 93 mummies that lived between 1300 BC — the late New Kingdom Period — and around 30 BC during the time of the Romans.

The mummies were buried at Abusir el-Meleq, which was an important religious and trading centre. Read more.

Australian funding agency announces new chief

From Nature Index, 28 April 2017:

The appointment of Sue Thomas as head of the Australian Research Council adds to a growing number of women at the helms of Australia’s key scientific agencies and funding bodies. Thomas, currently the provost and deputy Vice-Chancellor at the University of New England, will take over from Aidan Byrne on 3 July.

Her appointment means Australia’s two largest science funding agencies are now led by women, with Anne Kelso the CEO of the National Health and Medical Research Council. There’s also Margaret Hartley, who is the CEO of the Australian Academy of Technology and Engineering; Kylie Walker, the CEO of Science & Technology Australia (STA); and Anna-Maria Arabia, chief executive of the Australian Academy of Science. Read more.

Age discrimination: older Australian workers viewed as slow to learn

From The Guardian, 20 April 2017:

The trope of the older worker thrust back into the hurly-burly of working life made for great comedy in the 2015 film The Intern. But in reality this scenario isn’t always such a laughing matter.

Older workers face unique hardships. Hampered by unfair stereotypes about their abilities, their role in society and their responsibilities, they are regularly overlooked for interviews, jobs, promotions and recognition.

The Australian Human Rights Commission’s 2016 report Willing to Work found 27% of people over the age of 50 reported experiencing age discrimination at work, a third of the most recent episodes occurring when applying for a job. One-third of those gave up looking for work.

Age discrimination was particularly acute among older women, who were more likely to be viewed as having outdated skills, being slow to learn, or as being likely to do an unsatisfactory job. Seniors with disabilities face an even steeper uphill battle for jobs and recognition. Read more.

Alien solar system of seven Earth-sized planets orbiting nearby dwarf star could be rich with water and life

From ABC Science, 23 February 2017:

Seven Earth-sized planets, many of which could harbour life, have been discovered orbiting a dwarf star in our own galactic neighbourhood.

The complex alien solar system hosts the largest number yet of detected worlds capable of having liquid water on their surface, a team of astronomers reported on Thursday in the journal Nature.

The planets have been found around TRAPPIST-1, a Jupiter-sized ultra-cool star located 40 light-years away in the constellation of Aquarius.

“It’s the first time that we have so many Earth-sized planets around a star,” said lead author Dr Michaël Gillon, of the Space Sciences, Technologies and Astrophysics Research Institute in Belgium. Read more.

Pregnant reptile fossil suggests bird ancestors gave birth to live young

From ABC Science, 15 February 2017:

The discovery of a fossil of a pregnant marine reptile has provided the first evidence that an ancestor of modern-day birds and crocodiles gave birth to live young.

The fossil of the long-necked Dinocephalosaurus, which swam the seas during the Middle Triassic period around 245 million years ago, was unearthed by an international team of scientists in south-west China.

 

Inside the fossil was a much smaller fossil of the same species positioned in a way that suggested it was an embryo rather than the remains of prey, according to a paper published today in Nature Communications.

The marine reptile came from a group called the Archosauromorphs, which evolved 260 million years ago and includes modern-day birds and crocodiles, as well as extinct dinosaurs and pterosaurs. Read more.

Concrete products reabsorb nearly half CO2 released in cement manufacture

From ABC News in Science, 22 November 2016:

The production of cement is a major source of carbon dioxide, but new research suggests the material that makes up our concrete jungles also plays an important role in reabsorbing carbon emissions.

 

But as cement ages and weathers over time, it also absorbs carbon dioxide in a process called carbonation.

In a paper published today in Nature Geoscience, a team of researchers calculated that the carbonation process has offset as much as 43 per cent of the emissions associated with cement production, not including the emissions associated with fossil fuel use during cement production, over the past 70 years. Read more.