Australasian Science: Australia's authority on science since 1938

Cover Story

Cover Story

Genes that Cuddle in the Cold

Genes that Cuddle in the Cold

By Joshua Mylne

An ingenious experiment has allowed scientists to observe how plant genes move around the nucleus to locations that either stop or stimulate flowering depending on temperature.

Every cell of the humble model plant Arabidopsis contains five chromosomes, each of which carries about 5000 genes. Each cell stashes some of its genes away and keeps some in ready reserve, while the others remain active and busily make proteins.

After decades of effort, scientists feel like they have a good understanding of how genes are regulated between these active and inactive states, but it’s beginning to dawn on them just how much genes move around while this happens, and that this might be a part of the regulatory process.

Food Facts & Furphies

Food

More than 50% of Australians are taking some form of vitamins, minerals, complementary or herbal supplements yet the average Australian household spends just $13.70 per week on vegetables and $9.60 on fresh fruit.

By Clare Collins

New diet fads and furphies seem to appear every day. While some of these have a scientific basis, for others the science has changed in response to new discoveries or the science is just not there yet. This special issue of Australasian Science explores the latest evidence for food and nutrition.

“I took this rare superfood that only grows on the southern slope of an exotic mountain for 2 weeks per year and must be hand-picked at dawn. It costs $40 per kilo.” When I hear stories like this I cringe and wish I could convince people to save their $40 and spend the money on more vegetables and fruits. The evidence is clear that eating more fruit and veg will lower your risk of weight gain and of developing common conditions such as Type 2 diabetes, heart disease, stroke and some cancers.

Lies, Damn Lies, and Science

9/11

When a component of the numerous 9/11 theories became untenable, it was nevertheless weaved into a larger 9/11 conspiracy. Credit: flickr/ 9/11 photos (CC by 2.0)

By Stephan Lewandowsky, Gilles Gignac & Klaus Oberauer

Conspiratorial thinking is a major element in the rejection of a broad range of scientific findings, from climate change to tobacco, vaccinations, GM foods and the moon landing. But why?

Prince Phillip runs the world drug trade, the 9/11 attacks in the US were an “inside job” of the Bush administration, and US President Barak Obama’s Hawaiian birth certificate is a forgery. Oh, and climate change is a hoax perpetrated by corrupt scientists who just want more government grant money.

Stephan Lewandowsky is a Winthrop Professor at the University of Western Australia. Gilles Gignac earned his PhD at Swinburne University, and now specialises in statistics and psychometrics. Klaus Oberauer is Professor of Cognitive Psychology at the University of Zurich.

Cosmic Hotspots for Life

asteroid

Crater cooling over at least half a million years could have given primitive bacteria enough time to evolve.

By Martin Schmieder & Fred Jourdan

New evidence reveals that large meteorite impacts took long enough to cool for microbial life to emerge and thrive in the wet and warm conditions of the impact crater.

Species Are Shrinking

Credit: Romolo Tavani/Adobe

Credit: Romolo Tavani/Adobe

By Martino Malerba

An ingenious experiment has revealed the physiological reasons why many species are becoming smaller in response to global warming, overhunting and overfishing.

Human-related impacts on natural ecosystems are driving many species to evolve smaller body sizes. This could be because fishing and hunting are disproportionally targeting larger individuals, or because increasing temperatures due to global warming increase the food requirements for species, and this limits their size. These shifts toward smaller size are very common in nature, but we don’t yet know what the consequences are.

Pyrodiversity vs Biodiversity

Fire is a key part of ecosystems in the Mallee. Credit: Peter Teasdale

Fire is a key part of ecosystems in the Mallee. Credit: Peter Teasdale

By Dale Nimmo

New research challenges conventional wisdom that the creation of a diverse mosaic of fire histories benefits biodiversity.

Fire is a part of life in Australia. It can be an agent of destruction and loss, and it can promote regeneration and new life.

While most terrestrial ecosystems in Australia are fire-prone, our understanding of the relationships between fire regimes and the Australian flora and fauna remains limited. Such understanding is critical because inappropriate fire regimes – such as burning too little or too often – have been implicated in the decline and extinction of a range of native species.

Will Enhanced Soldiers Fight a Just War?

Revision Military’s prototype TALOS suit has a powered lower-body exoskeleton supporting a body armour system that can protect 60% of the body from rifle rounds. To relieve weight, motorised actuators pick up each leg and move them. The weight of the helmet, armour and vest is supported by a rigid articulated spine. The suit’s power pack has a cooling fan, and a cooling vest pumps water through 3 metres of tubing under the suit. Credit: Revision Military

Revision Military’s prototype TALOS suit has a powered lower-body exoskeleton supporting a body armour system that can protect 60% of the body from rifle rounds. To relieve weight, motorised actuators pick up each leg and move them. The weight of the helmet, armour and vest is supported by a rigid articulated spine. The suit’s power pack has a cooling fan, and a cooling vest pumps water through 3 metres of tubing under the suit. Credit: Revision Military

By Adam Henschke

Technologies may be able to enhance a soldier’s strength, endurance, stress tolerance and cognitive ability, but could they reduce their moral capacity to follow the laws of armed conflict?

As combinations of nano-, bio-, info- and cognitive technologies converge and combine, humanity is increasing its capacity to actively change and direct our physical nature. In contrast to evolution by natural selection, human enhancement involves the use of technological interventions to shape us as individuals in ways that we have selected.

The military context is one area where such technological enhancements are being extensively researched. The guiding thought is that technologically enhanced soldiers can increase a military force’s chances of winning.

Seven Discoveries that Changed the Course of Human Evolution

rafting

The best early evidence of a modern human voyage across large stretches of open water is the colonisation of Australia at least 50,000 years ago, navigating 50–90 km stretches of water where land could not be seen. Credit: Jamie Tufrey

By Paul Taçon

Seven discoveries made by our ancient ancestors were key cultural drivers that changed the course of human evolution in extraordinary ways.

When we ask people what they think are the top discoveries or inventions that transformed human evolution we get an interesting range of responses. Many people focus on things from relatively recent times, from cars to computers, the discovery of electricity or maybe the atom, from agriculture to the cotton gin, and even sliced bread and bottled beer!

But there are much earlier discoveries that led to all of these, as well as to understanding who we are as 21st century modern humans who are distinctly different from our earliest ancestors and other creatures.

Is an End to AIDS in Sight?

HIV virus attacking a cell. martynowi_cz/iStockphoto

HIV virus attacking a cell. martynowi_cz/iStockphoto

By David Harrich & Kirsten MacGregor

Gene therapy is showing promise as a way to turn HIV against itself and cure AIDS.

Los Angeles, 1986. A new virus is taking hold. It has only had a name for 3 years but its symptoms are already disturbingly familiar at emergency rooms across the USA. Young people are being struck down and fear – hysteria even – is growing in the community alongside misinformation. When I meet people and tell them where I work, they refuse to shake my hand for fear of catching the virus.

Why Are Males More at Risk in the Womb?

foetus

Birth weight and poor growth in the womb are associated with conditions appearing decades later, such as heart disease, hypertension, metabolic syndrome, diabetes and psychiatric disorders.

By Sam Buckberry & Claire Roberts

Subtle changes in the placenta before a child’s birth can affect its predisposition to chronic disease and premature death many years later – and unborn boys are most vulnerable.

Tiny and seemingly insignificant deviations from a rocket’s course at take-off can have significant and measurable effects on its ultimate trajectory. In a similar vein, could minute changes in the function of the human placenta before a child’s birth affect its predisposition to chronic disease and premature death many years later? And are males genetically more predisposed to problems while still in the womb than females? These questions are at the forefront of our research into sex differences in placental function and foetal growth.