Australasian Science: Australia's authority on science since 1938
Cover Story
Cover Story
New Ideas about the Neanderthal Extinction
A modern human cranium (left) and a Neanderthal cranium (right). Modern humans have a globe-shaped braincase with steep sides, our foreheads lack a prominent bony ridge about the eye sockets, and our faces are shorter and flatter with scalloped cheeks. Credit: BirdImages/iStockphoto
By Darren Curnoe
Were modern humans so superior that they drove Neanderthals to extinction, or did their lonely existence leave them genetically vulnerable?
The Neanderthals (Homo neanderthalensis) are a species of extinct human relatives that occupied Europe, West Asia and Central Asia from around 400,000 to a little less than 40,000 years ago. Science has known about them for more than 180 years, and they were the first extinct hominin to be discovered, pushing our understanding of human origins beyond a Biblical timeline for the Earth.
Why Our Brain Craves Random Noise
Credit: RyanJLane/iStockphoto
By John L. Bradshaw
Sensory deprivation, dreams, hallucinations and the detection of familiar patterns in clouds and repetitive sounds reveal our brain’s determination to make meaning from random noise.
In the 1960s, space was all the rage. We could fly folk to the Moon, but could we send spaceships further afield to film the planets? How would spacemen cope with a weightless state, and possibly very lengthy periods with greatly attenuated sensory input?
Horse Racing Position Cuts Drag by up to 66%
Researchers have quantified how much different slipstreaming tactics reduce drag on a horse during a race, with wind tunnel simulations showing that “getting cover” can reduce aerodynamic drag by up to 66% in horse races.
Jockeys can save racehorses critical energy by riding closely behind or alongside others to take advantage of slipstreaming, according to the simulations of aerodynamic drag conducted at RMIT University’s wind tunnel.
Should Australia Allow Mitochondrial Donation?
Credit: nobeastsofierce
By Ainsley Newson & Stephen Wilkinson
Is there any ethical reason why legislation should prevent the use of donor mitochondria in cases where children are likely to inherit mitochondrial disease from their mothers?
The transfer of a donor’s healthy mitochondria into a woman’s egg or early embryo aims to prevent a child from inheriting mitochondrial disease from its mother. In February 2015 the United Kingdom became the first country to allow the technique, and last month the US Institute of Medicine also determined that mitochondrial donation is acceptable in some circumstances.
A Different Angle on Earth’s Climate History
Credit: pongpongching/Adobe
By George Williams, Phillip Schmidt & Grant Young
Earth’s axial tilt affects our environment in many ways, but a much greater tilt in the remote geological past may have strongly influenced the planet’s climate history and the evolution of life.
Do you know what controls:
- the seasons, with warm summers and cool winters in middle latitudes, large seasonal temperature changes in high latitudes, and a consistent equatorial climate?
- the meridional temperature gradient, which runs north–south and explains why Darwin is warmer than Hobart, and why high latitudes have ice sheets while the equator is hot?
- the general direction of global oceanic circulation?
Could Sugarcane Prevent Diabetes?
Credit: Frog 974/Adobe
By Matthew Flavel & Barry Kitchen
When sugar is refined we are discarding antioxidants that not only temper metabolic diseases but can also restore insulin production.
According to the World Health Organisation, rates of obesity across the globe have tripled since 1975. The increase in obesity has also produced a rise in associated disorders such as type 2 diabetes and cardiovascular disease.
While these are multifactorial diseases, no factor receives more attention than sugar intake. Refined sugar consumption also increased dramatically in this time, and governments are now scrambling to curb this consumption by introducing taxes.
The Psychedelic Renaissance
Credit: agsandrew/Adobe
By Martin Williams & Melissa Warner
Recent studies are finding that psychedelic medicines are effective treatments for mental health disorders such as depression, anxiety, post-traumatic stress disorder and addiction.
Mental health statistics are sobering to read: 45% of Australians will experience a serious mental health illness in their lifetime, suicide is the leading cause of death among young people in Australia, and mental illness is predicted to become the leading cause of disability and disease worldwide by 2020. Awareness, education and better therapeutic solutions are required if we are to alleviate both the suffering of individuals and the burden of mental health disease on society.
The Moral Machine
Credit: the_lightwriter/adobe
By Guy Nolch
How can we program autonomous vehicles to make life-or-death decisions when our own moral values vary according to factors such as age, gender, socioeconomic status and culture?
Few of us will ever face a split-second life-or-death decision, yet every day many of these are made on our roads. In that instant, how do drivers choose the least devastating consequence when the choice of swerving left, right, or not at all will nevertheless result in tragedy?
Would you choose to spare the greatest number of lives? Or make a value judgement, saving a mother pushing a pram instead of an elderly couple? Would you save a businessman over a homeless man, a police officer over a drug dealer, an athlete over a slob, or simply a woman over a man?
The Big Picture on Nanoparticle Safety
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By Laurence Macia & Wojciech Chrzanowski
Nanoparticles are found in our food, cosmetics and tattoo inks, but regulations for their use aren’t keeping up with new research questioning their safety.
When Laura first wakes up, she makes a cup of white coffee with her capsule coffee machine. She then has a shower, uses some deodorant, applies a facial moisturising cream and foundation powder, brushes her teeth and puts on some lipstick, which she will reapply many times during the day. She is not so hungry as she had too much ice cream yesterday, so she will buy an iced doughnut on her way to the university. Outside, the sun is already up in the blue sky so she grabs some sunscreen to protect her skin. After a short walk she arrives for her chemistry class on food additives.
Inside the Lair of a Mysterious Cosmic Radio Burster
A flash from the Fast Radio Burst source FRB 121102 travelling towards the 100-metre Green Bank telescope in the USA. The burst shows a complicated structure, with multiple peaks that may be created during the burst’s emission or imparted during its 3-billion-light-year journey to us. This burst was detected using a new recording system developed by the Breakthrough Listen project. Credit: Danielle Futselaar/Shutterstock
By Charlotte Sobey
Two of the world’s largest radio telescopes have unveiled the astonishingly extreme and unusual environment of a mysterious source of repeating radio bursts emanating from 3 billion light-years away.
Once every 10 seconds, mysterious astrophysical objects blast swift, sudden radio flashes from across deep space. We call these signals “fast radio bursts’ (FRBs). New observations from two of the world’s largest radio telescopes have led us to a remarkable discovery about a unique FRB factory. We found that the source is embedded in a hot, dense environment with an exceptionally strong magnetic field. A compelling explanation is that it is situated in the neighbourhood of a massive black hole (https://goo.gl/NC1BKw).
Australasian Science July/August 2019
