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.