Science: a many-flavoured thing

It is normal to expect researchers to be comfortable when handling their study organisms, but where do you draw the line in terms of 'familiarity'? Personally, I would draw the line at basic handling and post-mortem dissections. Valerie Clark, a herpetologist studying frog toxins, has a different level of familiarity with her study organisms: back-licking! By licking frogs she can determine whether they are poisonous by the taste of their skin secretions. (Note: I do not recommend non-experts pick up frogs and lick them to see if they are poisonous). Most skin secretions of poisonous frogs can't kill a human, but it can cause throat burning and constriction, but when in the field with limited equipment, often the only way to tell whether you've found a poisonous frog is to give it a hearty lick on the back.

Poisonous Mantella frogs from Madagascar taste bitter-sweet

In a recent study, Clark used electrical stimulation to extract skin secretions from some poisonous frogs found in Madagascar. Apparently, licking these study frogs leaves a bitter-sweet taste. The reason for this taste is revealed by mass spectrometry of the secretion products: sucrose and a new bile (or stomach) acid called tauromantellic acid. Frogs typically don't generate their own poison, their guts actually sequester and remove it from insects that they eat so they themselves are not poisoned. Clark believes that the bile acid on the skin is involved in transporting toxins from the frog's gut to its skin. FYI: this does not happen in humans, if you eat something particularly nasty and don't seek medical help, it is likely you will just die. On that happy note, frogs are cute anyway, so who wouldn't want to lick them?!

Original article via National Geographic News.

I want free bee metabolic rates!

I've spent the last week compiling a datasheet on the measured metabolic rates of insects from around the world since the 1940s. Tedious? You bet. I need this database so that I can perform what is called a Phylogenetic Generalised Least Squares (PGLS) analysis using data on not just the metabolic rates of insects, but also phylogeny. The question I am asking is: how and what levels of rainfall and ranges in temperatures can influence the evolution of metabolic rate in insects? The problems with this type of analysis are many, yet in evolutionary physiology there is no better way to look at the data as yet. The biggest problem of all is that there is no resolved phylogeny for insects, and we aren't as close as we'd like to be either. Not that it helps that a couple thousand new species are discovered every year, but all I can do at this stage is analyse the data based on the best phylogeny available, and wait until an improved version comes out in the future.

At this stage, I am having difficulty getting enough data on flies and bees. There have been many measures of their metabolic rate, but few papers have specified where the animals were caught, and if they do, the flies and bees have been kept in the laboratory for so long it is pointless using their data to assess the influence of environmental variables I'm interested in on their metabolism.

Free the bees! I need data from bees OUTSIDE of cages! (Nick Cage would also appreciate bee-freeing)

Despite these minor hiccups and tedium associated with sitting at a computer, I actually am looking forward to staring at a computer screen and writing up a paper (I have mid-term review coming up!) on one of my earlier PGLS analyses on the evolution of reptile metabolic rate. Watch this space for my post of paper submission success!

Image: http://i3.kym-cdn.com/entries/icons/original/000/002/910/not-the-bees.jpg

The dwarf of Nosy Hara

While constructing a timetable of sorts on how to manage selection experiments and ensuing measures of fecundity and metabolic rate, I realised that the updates for PLoS ONEs releases from yesterday had not been checked in my emails' inbox. While scanning through the journicle titles, the key words "dwarf", "chameleon" and "Madagascar" captured my interest. It's always a pleasure to read about the new and interesting fauna being discovered in Madagascar, and even moreso when the alternative is to frown and fret over mistakes in ones' timetabling of experiments.

The newly discovered leaf chameleon has been declared as "an extreme example of island dwarfism".  For the record, island dwarfism is common; the limited space on islands typically place pressures on its' inhabitants to reproduce faster and deal with limitations in resources in order to survive as a species. The new miniature leaf chameleon was found on a very small islet called Nosy Hara in the north of Madagascar. The animal, endowed with the name Brookesia micra, has a total length in both sexes that is less than 30 mm, making it the tiniest amniote vertebrate in the world. Thankyou, says the Guiness Book of Records.

The tiniest amniote vertebrate in the world is incidentally the cutest as well.

It also turned out that once I had finished my timetabling of my experiment plans, I had also mixed up my fertility and metabolic rate experiments with the wrong generations. I had a very busy afternoon and am at least glad for the chameleons that they never have to endure the self-induced torture of a PhD.

Citation: Glaw F, Köhler J, Townsend TM, Vences M. (2012). Rivaling the world's smallest reptiles: discovery of miniaturized and microendemic new species of leaf chameleons (Brookesia) from northern Madagascar. PLoS ONE 7(2). doi:10.1371/journal.pone.0031314.

Image: Glaw F, et al. (2012). PLoS ONE. (A) Adult Brookesia micra, (B) and (C) are juvenile B. micra, and (D) is typical habitat on Nosy Hara, Madagascar.

Loose ends are tied!

Loose ends always need tying-up. Not that I have any serious loose ends, unless you call a $35, 000 HECS debt a loose end, but since the annual biosafety test for our school has become available, I've been meaning to complete the online assessment. And register for the Evolution conference that is being held in July. Not to mention all the administration forms I have yet to complete, and replying to multiple people about availabilities for tutoring this semester.... ok, so I have had a lot of small things building up over the last 4 months that needed to be done. But today I did it all, and I feel very relieved and happy. Seriously, if you're having a bad or unproductive day, tie-up those loose ends and you will have achieved something for the day and feel a lot better for it.

I also met up with another person who works with Drosophila fruit flies, to see what feeding protocols are used and how to distinguish between different larval stages. Conveniently, larval development is divided into four logical stages: L1, L2, L3, and L4. That much was easy to understand. I was surprised to learn just how fast generation time was in these guys; in 10 days an egg will become a sexually mature adult fly, given it was reared at 25 degrees C. To encourage females to lay their eggs, simply dye an apple juice-based medium blue, introduce to the female fly, then lo and behold, little white eggs will appear. Apparently, this only works for Drosophila melanogaster, not for other species like D. simulans.

Imagine little white eggs on a blue (in this case purple) medium. At least, I hope the eggs are actually white, because if they are clear I'm in trouble!

Now that I am officially registered for it, I am really excited about the Evolution conference to be held this year! It is going to be in Ottawa, Canada, and runs from 6-10th of July. My supervisor and I haven't really been to an international evolution conference before, so we aren't sure what to expect, and whether my research thus far is even worthy of presentation, seeing as we aren't even sure if it suits the draw crowd for the talk sessions. To spare the on-lookers the pain of being told what they already know, we agreed that I will just present a poster for this conference, and focus on learning and getting ideas for my own research. What am I most excited about for this conference? Definitely the networking!

Image: http://browse.deviantart.com/?qh=&section=&q=drosophila+melanogaster#/d148ear

Timing is everything, or, Just ask

Today is Friday, the 10th of February, 2012 AD, Epoch: Holocene. I have spent the last few days planning what methodology to employ in my selection experiments, and how best to manage time. Timing is everything. In the past I would have not bothered trying to timetable specifics for lab experiments, I would have just winged it and see how I fit everything in given 24 hrs in a day. That was part of the adventure in research, cramming an immense amount of work into the space of just 2 days due to poor planning. Ultimately, this led to disaster as organisms were forced to adapt to different conditions within stringent timeframes, giving me dicey data at best. Nature will always refuse to cooperate with my planning, so I need to change the way I think and cooperate with nature. Thankfully, that happened in Honours research, and now I am in my PhD with just a little more wisdom in my belt.

Drosophila kicking back and enjoying a cold one: nature's suggestion for Friday afternoon activities

I have never worked with Drosophila, so when I read papers about the types of correlates used to assess fitness in different lines of selection, I imagine that the work and time involved in performing these assessments is relatively easy and short. I mean, the methods section is easy and short to read, and Drosophila are small animals, so the process is likely to be easy, right? But, knowing my usual 'flawless' train of logic, I thought that this assumption is potentially detrimental to my research and it was time to talk to people who actually do this kind of stuff, to get a real answer. Lucky I did. Apparently, the logistics associated with what I was planning to do were insane - too much work for one person with time constraints. Even better: the people in this lab were very helpful and gave me some great suggestions for time-managing my experiments. I now have contacts who are also happy to train me in Drosophila husbandry and managing lines of selection. By simply asking people with experience, I have saved myself a lot of time and heartache. Drosophila, you guys are crazy!

Image: http://browse.deviantart.com/?q=drosophila&order=9&offset=24#/d2ynv1p

Glorious technology

Breakfast: a crumbed sausage and coke. I know that deep-fried food is probably not the best way to start the day but I could not help the food-urge. I had to indulge. On other news, in my quest to understand selection and what words like "isofemale" mean, I wondered at the simple yet effective piece of equipment I frequently read about that can be used to separate out fruit flies that have different tolerances to heat or the cold: the Weber column. Put simply, flies are dumped into the top of a tube, and water that is either heated or cooled to a desired temperature is pumped into a jacket surrounding the tube to control the air temperature experienced by the flies. As flies are KO'd by extremes in temperature, they fall out the bottom, meaning the last flies to fall out the bottom are the most tolerant to the temperature. Brilliant. If only all the equipment I have used in the past were that simple. 

Weber's gift to science: a column of awesomeness. Image based on that of Huey et al. (1992)

Apart from admiring simple technology, I found most of the afternoon drift along as I mined Google Scholar for journal articles (which I lovingly refer to as "journicles"). I am looking for what are worthy correlates for fruit flies that are selected for cold tolerance. So far, it seems the classic life-history angles of fecundity, development time, egg viability, and ageing, are the reasonable options. When it comes to physiological correlates, there is chill-coma recovery time and tolerances to heat (which would also involve using Weber's column!), but some measure of "willingness" to be active is, according to a paper by Latimer et al. (2011), probably worth my time as well. Because most people could not be bothered sitting around watching fruit flies walk around, there's some sexy "laser" technology on the block that can determine activity of fruit flies, referred to as DAMs (Drosophila Activity Monitors). I know that there is one of these DAMs in the biology school, so it would be cool to examine differences in activity in selected lines of fruit flies versus control lines. If I am able to play with these bits of equipment, then at this point in time lab work is going to be fun!

References:

Huey RB, Crill WD, Kingsolver JG, and Weber KE. (1992). A method for rapid measurement of heat or cold resistance of small insects. Functional Ecology 6:489-494.

Latimer CAL, Wilson RS, Chenoweth SF. (2011). Quantitative genetic variation for thermal performance curves within and among natural populations of Drosophila serrata. Journal of Evolutionary Biology 24:965-975.

A whole new direction

I've spent the last two years of my PhD floundering. It seems that every time I have found a new direction to take my research, some ethics or collection permit will stone-wall progress and I end up doing some statistics or correlative analysis in order to be remotely productive. Originally, I intended on looking into how pH affects fish metabolic rate, but collection permits fell through. So, then I decided to develop some correlative models for reptile and amphibian metabolic rate, which worked out well, only that I spent the whole time learning phylogenetics and advanced statistics and how to use the lovely R program without producing publishable results. The next plan was to do some lab-based work (which I wanted to do in the first place!) with reptiles and energetics. Ethics took their time to inform me I can essentially keep reptiles, but I'm not allowed to really do anything with the animals. In the end, I decided I needed to do some real lab-based science. I had worked so hard to stay away from things that don't have spines, but I swallowed my pride and decided the best model organism for me now to do some good hard-hittin' science is the fruit fly, Drosophila melanogaster. I am going to look at how selection for a specific physiological trait may involve a metabolic cost - the first study of its kind! Things are starting to look up!