Why are some animals larger than others? Often the simplest questions are the most difficult to answer. This didn’t stop Mehdi Khadraoui, whose interest in the evolution of body size took him on a search for a delicate wren with brilliant purple plumage, found only in the crocodile-infested Australian tropics. This was his fourth MEME semester, jointly supervised by Anne Peters from Monash University in Melbourne, Australia, and Wolfgang Forstmeier at the Max Planck Institute for Ornithology in Munich. Over a century ago, German anatomist Carl Bergmann observed that, on average, smaller animals were more common close to the warm tropics, whereas large animals tend to be found at higher latitudes. This makes sense: larger animals have an increased ratio of surface area to volume and are, in principle, better equipped to deal with seasonal changes in temperature. This came to be known as Bergmann’s rule. But does this “rule” hold up in light of modern evidence, and if so, what does it mean for the evolution of animals in a rapidly warming climate? Using over a decade’s worth of pedigree data from a population of purple-crowned fairywrens, Mehdi was able to ask a range of fundamental questions about the evolution of body size. Did nature or nurture better explain size differences? Are these differences associated with a warming climate, as Bergmann’s rule predicts? How does cooperative breeding, where offspring are raised by non-parental helpers, influence the evolution of body size? Mehdi pursued his interest in cooperative breeding as a PhD student at the University of Würzburg, where he is determining the proximate and ultimate mechanisms of sociality in fungus-farming wood-boring weevils. In this episode, Mehdi is interviewed by Henry North, who was in his final MEME semester at the University of Cambridge at the time of writing. Written by Henry North
Since recording, Mehdi has decided to switch careers from his announced PhD to pursue his passion for science communication and outreach. Follow Mehdi on twitter here!
If you are interested in Mehdi's project look up the Associate Professor Anne Peter's lab in Monash University. Mehdi also is a very talented artist - check out his website called Brush Tale! Subscribe and listen to MEME Stream on soundcloud! Follow us on twitter! This episode is brought to you by:
Mehdi and a purple-crowned fairywren (left), a purple-crowned fairywren (middle) and Mehdi in the field in Australia (right).
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About the MEME StreamA podcast following MEME students past and present on their adaptive walks of life as they embark on a career in evolutionary biology. The MEME is a unique masters program that enables upcoming evolutionary biologists from all over the globe to study and research in Europe. These podcasts will travel all over Europe and the world, leaping, as Richard Dawkins says, from brain to brain, MEME to MEME, telling tales of our scientific ventures and research projects. ArchivesCategories |