A short break

A quick post to say that I’m still here, I’ll just be taking a few months off to look after lovely little Ruth, who arrived a couple of weeks ago. My partner and I think she’s adorable… but that may be the oxytocin speaking.
Ruth

Small mammals vanish in Northern Australia

Captive breeding of Northern Quolls could be a last resort (Photo credit: Dyani Lewis)

Captive breeding of Northern Quolls could be a last resort (Photo credit: Dyani Lewis)

A couple of months ago I travelled to Kakadu National Park in Australia’s top end to join a team of ecologists monitoring mammal numbers in the park. I was there to report for Science [paywall] on why many of northern Australia’s small mammals are in precipitous decline, despite being in an area of largely intact tracts of vegetation. Tellingly, in the time I was there, and the 2 weeks that followed, just 3 small mammals were trapped. In the late 1980s, 30-40 per night would have been the norm.

The declines aren’t just occurring in Kakadu — right across Australia’s north, quolls, bandicoots, and native rodents are facing almost inevitable extinction unless the causes for their falling numbers are identified and addressed. The key culprits, it turns out, are feral cats and poor fire management.

Here’s the summary [full article is behind paywall]:

In northern Australia, mammal populations are in free fall. Over the past 2 decades, scientists have documented sharp declines in quolls, bandicoots, and other native fauna. The plight of these animals has grown so desperate that in July, the Australian government appointed the nation’s first threatened species commissioner, Gregory Andrews, a Department of the Environment staffer now tasked with devising broad approaches to stem the tide of extinctions. The solutions are not obvious, but mounting evidence points to the arch villain: feral cats, aided and abetted by fire. The Australian Wildlife Conservancy estimates that every day in Australia, an astounding 75 million animals fall prey to roughly 15 million feral cats.

What is good mental health?

(Photo credit: Viewminder via Flickr)

(Photo credit: Viewminder via Flickr)

When it comes to mental health, conditions like depression, anxiety, schizophrenia and bipolar disorder often come to mind. But does this mean that being without mental illness is the same as being mentally healthy? In an article for ABC Health & Wellbeing, I took a look at what it means to be mentally well, and what you can do to improve your mental wellbeing. Check it out here.

 

 

Natural value: Pricing ecosystems, and its implications for conservation policy

How do we decide who to protect? (photo credit: Rupert Ganzer via Flickr)

How do we decide who to protect? (photo credit: Rupert Ganzer via Flickr)

You don’t have to look far to find stories of species or ecosystems under threat. Whether it’s the critically endangered black rhinoceros in Africa, or the local wetlands under threat from urban sprawl, our collective failure to protect the world’s natural heritage can seem exasperating.

But in a world where resources to put toward protection are limited, making decisions about where to direct our efforts, or how to prioritise our donations, can be equally as frustrating. And it’s not just individuals who struggle with these choices — governments too are often faced with difficult decisions.

So how do we go about placing a value on our natural heritage? Should we even try to weigh the relative merits of saving one species or one ecosystem over another? And how can government policies help to guide us through the murky waters of environmental decision making?

To answers some of these questions, I was joined on Up Close recently by Brendan Wintle, a conservation ecologist who has been working with economists and policy makers to improve environmental decision making. Brendan is based at the School of Botany, at the University of Melbourne, and he’s also Deputy Director of the National Environmental Research Program Environmental Decisions Hub.

 

Ribosomes: Unlocking the secrets to your cellular protein factories

3D-printed model of a ribosome (photo credit: Steve Jurvetson via Flickr)

3D-printed model of a ribosome (photo credit: Steve Jurvetson via Flickr)

If I were to say the word ‘protein’, you’d probably think of a juicy steak, or perhaps a muscle-building protein shake. But in our bodies, proteins give us far more than just muscular bulk. They’re the enzymes that carry out cellular reactions — the microscopic sensors that allow us to detect the smell of a rose, or the pain of a burn. They’re the cement that connects our cells together, give our nose cartilage its rigidity and our skin its elasticity. And they serve all of these incredible functions in organisms from the lowly bacterium, to the majestic sequoia, and everything in between.

But proteins, in their myriad forms, could not exist without a complex piece of cellular machinery known as the ribosome. As important as it is, the ribosome — unlike the proteins it makes — is hardly a household name.

A few weeks ago on Up Close, I spoke to Ada Yonath, who won the Nobel Prize in Chemistry in 2009 for her pioneering work on the structure of the ribosome. She is now the Director of the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly at the Weizmann Institute of Science in Israel.

 

Altered expression: Epigenetics and its influence on human development

Tortoiseshell cats get their dappled colouration from X inactivation (photo credit: Tony Hammond via Flickr)

Tortoiseshell cats get their dappled colouration from X inactivation (photo credit: Tony Hammond via Flickr)

Our genetic make-up determines a lot about who we are – it determines whether we have blue eyes or brown, what blood group we have, or whether we’re predisposed to cystic fibrosis or sickle cell anaemia. But we’re beginning to learn that we’re far more than the sum of our genetic parts. Our genes only tell part of the story of who we are.

Just as important as what genes we’ve inherited from our parents, is how those genes are switched on and off throughout our lifetime. This complex system of genetic regulation has been the focus of the burgeoning field of epigenetics.

I was joined on Up Close recently by geneticist Marnie Blewitt. We chatted about epigenetics and her work on one of the coolest areas of epigenetics – X inactivation. Marnie heads a lab that studies epigenetics at the Walter and Eliza Hall Institute of Medical Research.

 

Could our furry friends’ features be the result of stem cell defects?

Silver fox displaying 'domestication syndrome' (Photo credit: luz rovira via Flickr)

Silver fox displaying ‘domestication syndrome’ (Photo credit: luz rovira via Flickr)

In the 1950s, Russian fox fur breeder Dmitri Belyaev embarked on a monumental experiment in the Siberian city of Novosibirsk. He wanted to see if he could domesticate wild foxes by selectively breeding only the tamest in each generation. He was essentially trying to re-run thousands of years of history — dogs and many of our farm animals were domesticated several thousand years ago, and scientists are still debating exactly how this occurred.

The Novosibirsk experiment is noteworthy not only because it revealed that tameness could indeed be bred into a line of wild animals after only a few generations. Nor because the landmark experiment is still running, sixty years on. It is noteworthy because it has demonstrated another aspect of domestication that biologists since Charles Darwin have puzzled over — that domesticated animals aren’t just tame, but they are cute to boot. Many have floppy ears, baby faces and endearing patches of white fur that could well spell death for an animal in the wild. In the Novosibirsk experiment, foxes started looking more like pets over the generations, even though the sole criterion for selection was tameness.

A threesome of academics has now come up with a hypothesis that could explain why selecting for a docile behaviour bring with it the suite of physical characteristics known as ‘domestication syndrome.’ According to the hypothesis, it could all come down to a group of stem cells called neural crest cells. These cells form near the spinal cord and then march across the developing vertebrate embryo to form pigment-producing melanocytes; bone, cartilage and teeth in the skull; and portions of the adrenal gland and brain.

The question that this hypothesis raises is: could small changes to neural crest cell gene expression be at the centre of domestication syndrome’s disparate features? Experimental evidence will need to sort the answer out to that, but it’s an intriguing idea nonetheless.

I wrote a brief article on the paper for Cosmos — check it out here.