This Week's Sci-Light!

High-speed time-lapse photos of a fruit fly banking away from a shadow threat coming from the bottom right and outside of the frame. Photograph credit: F. Muijres, University of Washington

Last week's Sci-Light was about the evolutionary development of Zebra stripes. To recap, Zebra stripes have evolved as a response to annoying biting flies. And just like Zebra's, we have developed our own technology to deter flies. For those of us who choose swatting away flies, have you ever been curious how a fly is able to dodge our efforts so well? Well you are not the only one, a bioengineer of Washington University was sci-curious too! Dr. Michael Dickinson has detailed the aerial movements flies employ to avoid our, and other animals, swatting. The characterized agile fly movements were published on April 10th in a paper entitled Flies Evade Looming Targets by Executing Rapid Visually Directed Banked Turns.

By recording Drosophila hydei (fruit flies) movements with a high speed camera capable of capturing 7,500 frames per second, Dickinson and his team of scientists could understand the 'blink of an eye' maneuvers these flies use in flight. To discover what Dickinson observed read about his research in the National Geographic article Mystery Solved: Why Flies Are So Hard to Swat. 

After that article, click the next link and discover what else you can learn!  
  

This Week's Sci-Light!

Credit: University of California, Davis campus

Tim Caro believes he and his team of researchers have discovered the reason Zebras have stripes.

I believe we can all agree zebra stripes are a peculiar phenomenon. What advantage would an animal ever have with such crazy stripes? What could ever be responsible for Zebra's avant-garde fashion sense?! Such a question has puzzled scientist's since Alfred Russel Wallace and Charles Darwin's era. Though many have pondered the curious stripes, little has been done to find answer. On April 1st, Tim Caro of UC Davis has published results that suggest he and his team of researcher's have figured out the mystery of zebra stripes.

In an article entitled The Function of Zebra Stripes published in Nature Communications, Tim Caro was able to approach the evolutionary question by utilizing multifactor models. Prior to Caro's publication, the leading hypotheses were as follows: zebra stripes may have developed as a means of camouflage, a method for disrupting predatory attack, a means of controlling temperature, a social function or a system to avoid parasitic attack from biting flies. Caro and his team could test the leading hypotheses according to a set of variables. The two part analysis started with testing how the five hypotheses correlated to thickness, location and intensity of stripes. The second part matched the five hypotheses and stripes to geographic ranges such as woodland areas, predator types, temperature and the distribution of two biting flies: horseflies and tsetse flies. As UC Davis reports in their News and Information column, Caro was amazed by their results - zebra stripes are the result of biting flies! Caro states, "again and again, there was greater striping on areas of the body in those parts of the world where there was more annoyance from biting flies.” Even more intriguing is that Caro's discovery makes one curious as to why flies are deterred from striped patterns. 

It is amazing how answers to questions can make new questions.  What are your new questions today?  They may not be about zebras, but rather closer to home.  Perhaps you're curious about what flowers or trees are blooming or delayed or maybe you're tracking the recent earthquakes.  Whatever is surrounding you or catching your attention, ask questions and seek answers.  Be Sci-Curious!

Written by Jacob Steenwyk
Edited by Cynthia Joseph