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Shape-Shifters

Tiger snakes on Chappell Island

Tiger snakes on Chappell Island have rapidly evolved large heads, enabling them to swallow whole mutton bird chicks. Photo © Ben Twist, used with permission.

By Michael Lee & Kate Sanders

Genetic analyses reveal that Australia’s land and sea snakes have rapidly evolved different body shapes and sizes to suit the local prey available, from fat muttonbird chicks to eels hiding in narrow crevices.

Snakes, being universally long and legless, would seem to have little latitude to vary their body shape. However, this apparent uniformity masks a lot of more subtle variation. Tree-dwelling snakes have thin, threadlike bodies with long tails, while ambush predators typically have thick stubby bodies and relatively short tails. Some of the most remarkable body shapes are found in sea snakes: most have ribbon-shaped bodies and paddle-like tails, and many have comically-tiny heads.

Michael Lee is a senior research scientist at the South Australian Museum and University of Adelaide. Kate Sanders is an ARC postdoctoral research fellow at the University of Adelaide.

Rewilding Australia

With the decline in Tasmanian devil numbers due to disease, carcasses now persist more than twice as long in Tasmanian landscapes. Credit: Rafael Ben-Ari/Adobe

With the decline in Tasmanian devil numbers due to disease, carcasses now persist more than twice as long in Tasmanian landscapes. Credit: Rafael Ben-Ari/Adobe

By Chris Johnson

Sometimes the best way to conserve biodiversity is to stand back and let wild animals do the hard work of ecological management.

In December 2012, the Copenhagen Post reported a discovery that marked a historic turning point for nature in Denmark: the first confirmed record of a wolf in the country in 200 years. Since then, more wolves have been found in the same area, suggesting the existence of a resident pack. One of the most developed countries in Europe just got a bit wilder.

Future-Proofing Students

Future-Proofing Students

By Nicholas Wyman

Ten partnerships are piloting an innovative program that provides high school students with an industry-supported pathway to a STEM-related qualification.

It’s not every day Year 9 students get to see and touch F/A-18 Fighter Hornets, but recently a group of students from Hunter River High School in NSW took up an invitation from BAE Systems to do just that. “Our guides showed us the insides of the hornets as well as letting us see the production line of these beasts,” said students Tiane and Gabby. “We felt so excited. We could have run a marathon. To us, this will be forever in our memory and the start of a passion for our own P-TECH journey at school.”

The Biggest Fertility Issue

Credit: Olivier Le Moal/Adobe

Credit: Olivier Le Moal/Adobe

By Tod Fullston, Jemma Evans & Macarena Gonzalez

Emerging evidence indicates that an obese mother or father predisposes their child to obesity via nutritional signals conveyed before birth.

Australia is currently ranked as one of the fattest nations in the world. The Australian Bureau of Statistics reports that a staggering 15 million (63%) Australians are overweight (BMI>25, 8.5 million) or obese (BMI>30, 6.5 million), and that the biggest increases are being seen in the morbidly obese class (BMI>40). Obesity is a known risk factor for debilitating diseases including type 2 diabetes, heart disease and cancer.

This Little Piggie Went Wee Wee Wee

Credit: dusanpetkovic1/Adobe

Credit: dusanpetkovic1/Adobe

By Jeremy Ayre & Navid Moheimani

Microalgae strains that can survive the extreme conditions in piggery effluent could not only clean up the wastewater but also reduce greenhouse emissions, provide a source of biofuel and even be fed back to the pigs.

Pork is the most highly consumed animal meat globally, with the pig population currently numbering around 900 million worldwide. Australia has roughly one pig for every ten citizens, so pig production here requires significant effort to keep environmental impacts in check while remaining economically viable.

A Stone Age “Rosetta Stone”

Image credits: R. Fullagar and J. Field

Modern experiments form the basis for studying use-wear on archaeological artefacts and microscopic residues preserved on ancient tools. The inset photos show a fish scale on a Pleistocene stone tool from Siberia (scale bar 1 mm), a grass compound starch grain from a Pleistocene grinding stone in Australia (scale bar 0.01 mm) and a grass phytolith from the same grinding stone (scale bar 0.005 mm). Images: R. Fullagar (main photo, fish scale) and J. Field (starch grain, phytolith)

By Richard “Bert” Roberts, Richard Fullagar & Linda Prinsloo

Our ancestors had the edge over several other contemporary species of human that were headed for extinction by about 40,000 years ago. What were they doing differently? Archaeological scientists are trying to find out using modern techniques to study traces of use left on stone tools and other artefacts.

Deciphering what our ancestors were doing in the distant past, and how this sheds light on the evolution of the human body and mind, are fascinating but immensely challenging topics. They are not made any easier by the scarcity of human bones and teeth and by the generally poor preservation of organic matter at timescales stretching back tens of thousands of years and longer.

Mammals on the Brink

short-eared rock wallabies

Perhaps because of their rocky, inaccessible habitat, short-eared rock wallabies are one of a few species whose populations remain healthy in much of the Northern Territory. Credit: Ian Morris

By Mark Ziembicki

Traditional ecological knowledge and western science have combined to address one of Australia’s most pressing biodiversity conservation issues – the decline of its native mammal species.

Pulling into Mapuru, a remote outstation on the edge of the Arnhem Land plateau, our car is held hostage by a large pack of barking camp dogs. Unwilling to brave an exit, we remain trapped until some local kids chase the canines away and we cautiously step out of the vehicle to be welcomed by our hosts, the traditional land owners of the area. As the dogs hover at a distance I wonder whether they somehow sense what is in the back of our ute.

Tropical Invaders Seek a Cool Change

 Moorish idol

Larger-bodied tropical species, such as the Moorish idol, are more likely to show vagrant behaviour into high latitude regions.

By David A. Feary & David Harasti

As oceans warm, a new study has shown that certain measurable traits may help scientists predict which species of tropical fish will successfully shift into cooler temperate waters.

Changes in global climate are a substantial threat to bio­diversity. Some species are able to cope with the associated warming by shifting their geographic range. Although there is considerable variation in these responses, average range shifts up to 6.1 km/decade in terrestrial communities and up to 28 km/decade in marine communities have been reported. These shifts are being described as one of the most dramatic results of climate change.

Can Diet Be Tailored to Suit Our Genes?

foetus

The long-term impact of what your mother ate and drank, whether she was underweight or overweight and whether she smoked during pregnancy influences your chances of becoming obese, diabetic and even developing certain cancers.

By Helen Truby

Lifestyle factors such as a eating plenty of fruit and vegetables, getting a good night’s sleep and keeping physically active are the best way to help your genes keep you healthy.

The completion of the human genome project heralded an era of possibility that we would be able to predict our risk of developing diseases and design effective preventative initiatives. From a nutritionist’s point of view, direct links between health outcomes and food are tantalising, and beg the question: “Is your health destiny already fixed via our genetic code or can our food and lifestyle choices make a difference?”

What Speed Sperm Should a Sea Squirt Squirt?

Sea Squirt

Sea squirts reproduce by broadcast spawning, where eggs and sperm are released into the ocean and the sperm have to swim around to find an egg to fertilise.

By Angela Crean

Sea squirt sperm is revealing how a male’s environment affects his sperm’s quality, with implications for the health of offspring that could also improve the success of human IVF procedures.

A sperm’s job is to swim to an egg and deliver the male DNA. So, sperm have essentially been likened to a car – the speed or quality of the sperm can influence its chances of successfully reaching an egg but, once the cargo is dropped off, the sperm’s quality is not expected to have any further influence on the development or health of the offspring.

The humble sea squirt suggests this assumption is wrong, and what we’ve learned from sea squirt fertilisation could be applied to make IVF more efficient.