Monday, June 2, 2014

Too Much Sex is Sometimes Deadly

This is an antechinus - a mouse-sized, shrew-nosed marsupial that's one of the world's only mammals to breed suicidally. To these guys, sex really is everything. After an epic 2 to 3 week breeding period (defined by a series of 12 to 14 hour copulations), all adult males die. Females live a few months longer, but fewer than 15% survive the energetic demands of lactation to breed again. 

the antechinus : Australia's sex-obsessed marsupial mouse

Relatively speaking, male antechinus aren't that aggressive, and winning fertilisation rights occurs via competition among sperm rather than battles between males for females. Female antechinus are promiscuous, mating with multiple males (and accumulating their sperm) over the breeding season, and a female's litter of 8 to 10 offspring may be sired by several different males. We still don't know how sperm form or function contributes to fertilisation success - but I plan to spend some interesting hours collecting antechinus sperm later this year, so I'll get back to you on that one.

it takes balls to live like this (and yep, there they are!)

And how do antechinus die? It's not pleasant. Previous studies show us that males succumb to immune collapse and gastric ulceration as a result of extreme stress. Females merely starve.

It seems incredible that this kind of breeding system might evolve - almost a complete population turnover each year, males never seeing their own offspring, and yet ... we see this life history (called semelparity) in several species of marsupials within the family Dasyuridae. The short and dramatic lifespans of these animals makes them an ideal system for looking at the ecology, physiology, molecular bases of ageing and death in the wild - which is why I'm spending the next few years working with them.

But shit. It's not going to be easy to watch when the little buggers start to degrade. Because as it turns out, dying from too much sex isn't so fun after all ...


Monday, February 3, 2014

What about caloric restriction?

caloric restriction - is it the key to longevity?
Considering the latest 5:2 diet?
Planning to restrict your research animals' diet to keep them alive? 

Before you do, watch this video on caloric restriction by one of the world's leading researchers on ageing, Steven Austad.

I've been thinking a lot about this stuff, both in my personal life and research life. How can I extend my own lifespan, and that of the wild marsupials I study? Do I merely need to cut back on calories a few days a week? Fast periodically? Should I be feeding antechinus to make them live longer, or limiting their intake? At the moment, the jury's out for me - in the video (albeit a couple years old) Austad makes some excellent points about wild vs. lab animals that I think need to be considered.

In science, the easiest way to look for differences among animals is to make them as similar to begin with as possible. Trust me, it makes sense - and here's how: by reducing genetic differences between individuals, you can feel more confident that the differences you see between your experimental groups are from the experimental treatments themselves. In an ideal world, you'd have genetically-identical clones to work with - to calorically restrict or not - and that's why so many people out there work on bacteria (which you can clone). But if you're interested in mammals, you're stuck with some level of genetic variation.

In the lab, you can breed animals with their close relatives to reduce genetic diversity - and that's what most medical science does. But in the real world? Not a chance. In the wild, diversity in genes and gene expression forms the basis of evolution - and according to Austad, may be what makes caloric restriction work in some cases and not others, even within the same species. It's also why Austad - and many others - have long championed studying ageing in the wild.

Tricky business, this biology ... and I'd love to talk more about it, but I've got a pizza to eat ...

Tuesday, June 18, 2013

Evolution and Cancer - the IBECC 2013

I was in San Francisco [in June] for a multi-disciplinary conference - the International Biannual Evolution and Cancer Conference (IBECC) - my first in my new area of research, on evolution and cancer (and aging). The conference itself was all about applying evolutionary principles to the study of cancer - how it develops, how it metastasizes, and how it might be controlled. Intellectually, the talks were fascinating. Viscerally, they were terrifying. Because every time someone talked about how cancer cells spread through the human body, I felt a sinister clenching in my gut. Do I still have cancer cells in my body? Are they just dormant?

I learned that the future of cancer medicine seems to be in treating it as a long-term, chronic disease - something you just live with, instead of 'cure'. Because cancer, I'm afraid to say, is one of those things that just happens when you get a bunch of cells living and working together. Now and then, some of those cells lose their ability to work together, and revert to wanting only to promote/grow/copy themselves. That's cancer, and in all honesty, it's inevitable. One of the things they teach us in cell biology class is that we all get cancer everyday - it's just that our bodies naturally fight off these kinds of cells. This is why maintaining good health can help us reduce our risk of cancer.

Maybe I'll never know why my body let cancer grow in it, but this conference gave me both hope for a future without cancer, and hope for a future with it (should it ever come back).

cancer research

In the meantime, I'm going to keep myself healthy and live this life like it's the only one I've got. As I've written before, there's no such thing as 'cancer-proofing' ourselves ... yet, there's so much we can do to empower our bodies' natural defenses - give ourselves the tools to fight diseases of all sorts, including cancer. Varied and nutritious food, plenty of exercise, mindful living, a sense of adventure ... as far as I'm concerned, these are the keys to Life with a Capital L.

It's funny, I just spent a week learning about cancer - feeling disgusted and intrigued and astounded, but never demoralised. I never felt like there was no hope, because there is hope. There's always hope.


PS. If you'd like to learn more about the conference or about how evolution and ecology are being applied to cancer research, I recommend you join the Evolution, Ecology and Cancer Google+ community here.

Wednesday, June 5, 2013

An Open Letter from the Post-Doc with One Foot in the Pipeline

This post is from a former blogging life, i.e. before I got a research fellowship!! But it's still *very* relevant:

A Letter from the Post-Doc with One Foot in the Pipeline
(in response to: Nature 471, 7 (2011))

To Whomever Has the Power to Do Something About This:

Trust me, you want me to stay.

You’ve spent considerable time and money training me, culturing me academically. Now here I am, in the vastness of life-after-PhD, fending for myself. Sink or swim – I know that’s how this game works … but I don’t want to do either. What I want doesn’t exist yet.

(This is one of the ways I can help you.)

You may not realize it, but I am your future. I am the woman scientist with one foot in the pipeline. I am the post-doc who wants it all. I want to mentor students and inspire lecture attendance and create, learn, discover. But I also want to run on dewy mornings, and bake cookies with my daughter afterschool, and nurture those parts of me that – gasp! – aren’t related to my publication record. And though I used to think I wanted to be an academic (hence, the training), the reality is - I don’t have the time. My day only has 24 hours and I don’t want to spend all of them working.

But I do like being part of academic life. I’m smart, I’m experienced, and I can help transform the way this university trains modern scientists. How? You want skill transference. You want research-based learning. You want meaningful assessment. Simultaneously, you want academics to be more productive, get more grants, and train more postgrads. So, here’s all I’m saying -
Let. Me. Help. You.

I’m enthusiastic. I’m motivated. I even know my way around technology and social media. So let me take care of some things for you. Let me help you make this a better place for learning and research.

And, if you don’t snag me now, I might just form a consulting company and charge you triple later.

So trust me, you want me to stay.

Dr Amanda Niehaus
Mother of one, part-time post-doc & idealist
School of Biological Sciences,
The University of Queensland
Brisbane, Australia

PS. You can see an abbreviated version of this letter in the Australian Higher Education edition here.

Saturday, June 1, 2013

Who Am I?

I'm an ecologist - lab and field - who's obsessed with not dying. I had cancer just around the time I finished my PhD, which inspired me to transition into research on ageing. Why not devote the scientific side of my brain to something totally and utterly selfish? And very, very interesting.

But I haven't always studied this stuff - most of my early years were spent in the field, monitoring the reproduction, nest depredation and migration of birds.

Here's what I learned during that time: 
During my BSc at U Iowa, I ran a 3-field season honours project that taught me how to keep fieldwork under control, and how not to lose it when a storm destroys your field site. I learned that catching wintering songbirds at dawn in Iowa is cold business, and I vowed never again to work on birds (ha). By the way, woodpeckers have very spiky tongues. I also worked for 4 years in a Howard Hughes Research Institute lab (studying cystic fibrosis) doing fun projects like bacterial culture, fly testes dissection, mouse performance testing, and PCR running. Also, a helluva lot of autoclaving.

After my BSc, I did research for a breeding season at the largest Magellanic penguin colony in South America. I learned Argentine Spanish (eventually) and enjoyed a fair few boxes of Mendoza wine. This was where I came to understand the tragedy of reproduction in the wild, when our field site flooded and we had to go out and get one last measurement of each dead and bloated chicks. We lost about 80% of them.

During my MSc at Simon Fraser, I spent a summer in remote Alaska and several fall migrations ankle deep in British Columbia mudflats. Up north, I saw a lot of death and a lot of life, and I got used to hip waders and long underwear. I fell in love with the wildness of the places. I see now that I had my head up my own ass a lot of the time - but what do you do, when you're 20-something and headstrong?

I came to U Queensland to do a PhD in ecophysiology, because I was interested not only in behaviour but the physiology underlying it. [It's an interesting transition for me - I seem to be digging deeper into the body the further on I go ... ] In the beautiful Australian subtropics, I spent most of my time in a controlled temperature room raising tadpoles, weighing tadpoles, swimming tadpoles, feeding tadpoles, measuring metabolic rate of tadpoles, and adjusting temperatures. I evolved into a little bit of a control freak, and liked it.

Then, cancer. If you want to know more about that, head over here.

Currently, I'm on a 3-year full-time (taken at 5 years part-time) Australian Research Council research fellowship to study ageing in the wild. I'm still here at U Queensland, but after years of work on various birds, fish, amphibians, insects and even humans, I'm finally studying wild mammals. Of the marsupial ilk.

Want to learn more about what I'm doing currently? Click here.

You can also click these links for my full list of academic and non-academic publications, as well as my CV.


Thursday, March 7, 2013

Why Studying Death Becomes More Interesting After You Almost Die Yourself

It's so hard to know where to begin, because I began so long ago. I want to tell you all about the research I'll be doing, but the backstory itself is interesting ... because I wasn't always interested in studying death

Yep, that's right. I'm studying death - and, even better - premature death.

fieldwork on Groote Eylandt
No, my interest in mortality came via a reflection of my own mortality. A brush with death itself, via breast cancer. Before that, I'd looked at science with an idle curiosity; I'd studied things like predation of songbird nests in forest fragments, or the evolution of shorebird migration patterns, or the responses of tadpoles to extreme temperature fluctuations. Interesting things, yes, but these weren't questions burning within my soul or anything. 

But after cancer? I wanted to KNOW things. I wanted to know more about this tricky business of cancer, of dying. Pull the shell off the beast and expose answers - naked and writhing and primordial. 

Undoubtedly, subconsciously, to figure out how not to die myself.

I'm not the only one interested in death. You'll find it's central to almost any scientific discipline - including medicine, evolutionary ecology and physiology - as well as pretty much any non-scientific discipline. Ever heard a song about death? Read a story about it? Death has us all by the balls, so to speak, so it plays a big role in our society. 

Over the course of my fellowship, I'll be focusing primarily on premature death - the kind that happens for some animals that breed breed breed for a brief, coarse season and then die. In evolutionary circles, this pattern of life is called semelparity. We humans aren't semelparous, as we (usually) have a long and happy post-reproductive life.

But a chihuahua-sized, carnivorous marsupial called the northern quoll (Dasyurus hallucatus) - found only in northern Australia - doesn't have it so lucky. In perhaps the single worst example of deadbeat parenting, male northern quolls completely, naturally die off after the breeding season. I know it's not their fault, but still ... entire populations of them die, leaving females to raise up to 8 young on their own. As an evolutionary reward, the females get to live another year, breeding again and raising another batch of pups, before they too die. It's a life lived hard and fast.

female quoll with large pouch-young attached to her teats
I want to know why males die after breeding - specifically, why every male in some populations seems to die while some males in other populations survive the year to breed again. What drives this variation? Is it local environmental differences? Is it related to metabolism? To answer these questions, I'll be looking at quolls from an ecological level all the way down to a cellular level. 

I think what I find will be interesting, will help us understand aging - and death - in a whole new way.

So that's the plan, and I've just started work on it all. I'm sure I'll have lots of things to share about my project and the reading and fieldworking I'll be doing for it - but in the meantime, I'll be writing some posts about some inspiring research going on in my lab-group and department. And probably some highly-opinionated pieces about academic life in general, because I can't help myself.

On that note,
Happy International Women's Day,
Amanda xx