Experimental evolution of the food preference of Caenorhabditis elegans

Food preferences are highly variable across the animal kingdom. Some species eat a lot of varied food, and other species are known for only eating one specific type of food. Every species has their own preferences and adaptations to certain food sources. To get a better understanding on how the evolution of the food preference works, I conducted artificial selection for food preference in the nematode <em>Caenorhabditis elegans</em>. I determined food preference between <em>Escherichia coli</em> strain OP50 and <em>Bacillus megaterium</em> of nematodes that had been allowed to adapt to <em>B. megaterium</em> for 16 weeks. To see whether the food preference can also evolve without adaptation to that food source first, I looked at what happens when applying a selection pressure on the nematodes for food preference alone. Nematodes that had time to adapt to <em>B. megaterium</em> showed a weaker preference for <em>E. coli</em> OP50 than the control. This means that the preference is possibly genetic and therefore can evolve and be selected for. After 5 weeks of selecting for a preference for B. megaterium, there seemed to have changed something in the preference of the nematodes. However, further research needs to be conducted to make sure. In conclusion, the food preference of <em>C. elegans</em> can evolve after being adapted to the food source. Selection on the food preference itself seems to be possible but needs further study.