The Secret Superpower of Frogs

by Simon Tang (2022 Honours Student) 

An intense, murky river. Densely packed trees, twisting into each other and Mother Earth below. Decaying detritus scattered throughout the landscape. This pulsating ecosystem is not the most welcoming of places. Many dare not to stay for too long, to avoid angering an infected mosquito, or brushing too close to a leech. In such a disease-riddled habitat, where bacteria and fungi fester and multiply, what thrives?

In the distance, the unperturbed croak of a frog, lazily perched atop a stone, reminds us of who prevails in these lands.

The frog is an enigmatic creature. While seemingly unassuming in appearance, they secretly walk a fine line between survival and destruction. This balancing act exists only as a result of their skin, a paradoxical blessing and curse. Frogs bear primitive, inefficient lungs, and so rely on their skin as a secondary respiratory organ to absorb enough oxygen. To sufficiently compensate for their lungs, their skin must be moist at all times, as water allows for more air to permeate into the skin. As a result, they are perpetually married to rivers and ponds, spending nearly their entire lives around them. While these water bodies are intrinsically life-giving, the enemy is never too far. Armies of hostile diseases lie beneath the water surface, primed to usurp the delicate skin that awaits them.

Fortunately, this is no new foe for the frog. Over millions of years of evolution, frogs have accrued an impressive catalogue of chemical weapons tailored to neutralise these microbes. When the microscopic enemies begin their attack, the frog secretes a powerful, antimicrobial serum from their skin. Like waves of infantry soldiers, these secretions are efficient, and leave little in their way. After a tough battle, the enemy side has been defeated. The frog can rest easy, and breathe for another day.


In some ways, the chemical warfare between the frog and diseases reflects our own battle with pathogens. Over hundreds of years of research, we have developed our own chemical fleet of medicines and therapeutics to treat a range of diseases. When we are being overwhelmed by infections and illness, a simple pill can turn the tide.

However, the tide is turning back. Over the past few years, we have become intimately aware of how bacteria and viruses can impact our lives, and the devastating effects they can have on society. Diseases that were once thought to be controlled are now coming back, stronger than ever. Many animal diseases are also crossing the species barrier to infect humans, exposing us to diseases we have never experienced before. We are currently facing a pathogenic assault on all fronts, and our weapons are dwindling.

To help better treat diseases, my honours project is taking a closer look at the frogs around us. Through identifying the specific, bioactive peptides in the skin secretions of frogs, I am discovering unique molecules with disease-killing properties that have never been exploited before. These compounds have the potential to help inform better drug design, or even to be directly translated into novel treatments for human diseases.  

In a world where infectious diseases threaten to take over, our unlikely superhero might be hidden in a riverbank, sunbathing on a stone.


Simon Tang (2022 Honours Student) is creating a reference genome for the stuttering frog (Mixophyes balbus) for the purpose of characterising novel antimicrobial peptides.


Why I flew halfway around the world to study two small lizards at the University of Sydney

by Tristan Dodge (Fullbright Scholar)​

Now that you’ve been drawn in by my clickbait headline, allow me to introduce myself — my name is Tris and I’m visiting AWGG on a Fulbright Scholarship, which is an exchange program with the United States.

I’m an evolutionary biologist. Back home I’m a first-year PhD student at Stanford University, where I use genetic tools to understand ‘why do animals and plants look the way they do?’. There are actually two parts to this question:

  1. ‘what mutations in DNA sequences cause differences?’
  2. ‘why would such changes be beneficial and maintained over time?’

To answer these questions, my lab studies a group of freshwater fish species from Mexico called swordtails. My PhD research aims to understand why some fish have spots on their tail, some have spots on their bellies, and others have no spots at all. But while my PhD research will help us understand how evolution works in nature, it has little impact on the daily lives of species. For that reason, I wanted to do something that would contribute to help combatting the “biodiversity crisis”, a global issue where many species are threatened by extinction. The Fulbright scholarship’s mission of international collaboration fit nicely with this aim, so I jumped when the opportunity came.

So what’s the story with these lizards?

These lizards—the Christmas Island bluetailed skink and Lister’s gecko—have the unfortunate distinction of being the only two reptile species classified as extinct-in-the-wild. They’re both from Christmas Island, Australia, and almost went extinct in 2010 when invasive wolf snakes and giant centipedes ate all but 60 skinks and 40 geckos. These last few survivors were taken into captivity. Usually, when a species goes extinct in the wild, it tends to go permanently extinct shortly afterwards. But these reptiles have a fighting chance. Their numbers have increased over a decade of breeding to over 1000 individuals. And while Christmas Island is still unfriendly to lizards because the invasive snakes and centipedes are still around, hundreds of skinks have been released onto a neighboring predator-free island. 

But what does fish spot evolution have to do with reptile conservation? 

Evolution and conservation are tightly intertwined, and we can use similar genetic tools to gain insights into both processes.

Evolution has given rise to the biodiversity that we are now trying to conserve. Species are the way they are because their genes have evolved in response to a set of conditions, which humans are now rapidly changing, often too quickly for species to adapt in response.

Genetics can be a powerful tool for conservation. DNA sequencing is a process where we take an organism and break chromosomes from many of its cells into little pieces of DNA and read their bases (abbreviated as A,T,C, and G). This process has gotten much better over the last couple years: with today’s sequencing technologies, we can get millions of ‘reads’ back that are both very long (>10 thousand bases) and very accurate (fewer than 1 in 1000 bases are incorrect). 

My job is to use a computer to put those pieces back together and ideally make a single string of DNA for each chromosome (these chromosomes be anywhere from tens to hundreds of millions of bases long!). Then by then looking at differences in the DNA that each reptiles got from their mom and dad, specifically, where in the genome these differences happen, we can learn a lot of cool things that are directly relevant to conservation. For example, we can use these patterns to estimate historical population sizes, figure out how inbred an individual is, and predict mutations that might cause disease. Because this skink is a male and skinks tend to have X and Y chromosomes, we can also use this genome to develop tests to see if baby skinks are male or female (before you can tell by just looking at them). 

And what’s the point of it all?

By figuring all these things out, we can better manage captive populations of reptiles which will improve the species’ chances of survival. Importantly, figuring out how to save these extinct in the wild species holds lessons for other extinct in the wild species, which will likely increase as habitats continue to be degraded and invasive species continue to spread. Armed with insights gained from genetic tools, I hope we can reverse this extinction trend.


Tris Dodge

Tristan Dodge | Fullbright Scholar


Should I be afraid of the humble platypus?

by Adele Gonsalvez (2022 Honours Student)

The platypus.

Cute, cuddly, a collection of disparate animal features somehow merged into one animal?



Surely not.

But alas, just when you’d thought this Australian native couldn’t get any more bizarre (being egg-laying mammals and all) you’d be surprised again. Unbeknownst to many, the platypus is venomous – in fact, one of only a handful of venomous mammals in existence. Their secret weapon is attached to the ankles of their hindfeet – a spike-like spur connected to a venom gland. By wrapping their legs around their victim, they can jab their spur in and deliver venom into that poor unfortunate soul.

Now, who could possibly on the receiving end of the platypus’ venomous spur? The answer: the platypus. That’s right – the wrath of the platypus (in venom form) is unleashed against other platypuses. Male platypuses to be precise. You see, while female platypuses are born with spurs, they lose them by one year of age, meaning only male platypuses are venomous. The males use their venom against each other when in competition during the breeding season. The solid platypus logic is that in order to increase your own mating success, it helps to get rival males out of the picture – and injecting them with venom that causes temporary limb paralysis and a lot of pain, is an effective way to achieve this.

Now, should you be adding the platypus to your “Aussie animals who can kill me” list? Not quite. Platypus venom is yet to cause any human fatalities, and platypus envenomation in humans is quite rare. But it still packs a mean punch. Excruciating pain unable to be relieved by painkillers or first aid, and symptoms including nausea and gastric pain possibly persisting for weeks, certainly doesn’t sound like an enjoyable experience. In those few cases of humans being on the receiving end of platypus venom however, it generally only occurs when humans are physically handling platypuses, often zookeepers or fisherman. So, keep your hands to yourself and you should be right.

If you are ever lucky enough to see a platypus in the wild, floating down a river or chilling on the banks, there’s no need to be afraid. Just give the little guy some personal space and you should be at no risk of experiencing platypus venom.

Unless you are another male platypus during breeding season – well, in that case…

You should be afraid.


Adele Gonsalvez (2022 Honours Student) is investigating the expression and the antimicrobial activity of defensins from the platypus and short-beaked echidna.

Platypus photo by Kimberley Bateley