Welcome to the final installment of the Joseph Moore Museum’s trip to the University of Michigan. If you didn’t catch the first two posts, scroll below!
March 11th saw us once again up bright and early to attend the 13th Annual University of Michigan Early Career Scientists Symposium (say that ten times fast!). This year’s topic was the Ecology and Evolutionary Biology of Phenotypic Plasticity. Phenotypic plasticity is the ability of an organism to change its phenotype in response to different environmental conditions. A phenotype is the physical expression of a genotype, which is an individual organism’s set of genes. Phenotypic plasticity can include behavioral, physiological, and morphological changes that occur over an individual organism’s lifespan in response to new environmental conditions.
There is a lot of exciting research happening on how phenotypic plasticity evolves and how it affects ecological systems. While we heard a full day of fascinating talks, we’ll just highlight some of our favorites.
Dr. Holly Moeller’s gave a talk entitled Trade, Borrow, or Steal: How acquired metabolism confers phenotypic plasticity. She explored the way different organisms can actually change their metabolism (way of obtaining energy) by taking cellular machinery from other organisms or developing mutualistic metabolic relationships. Marine ciliates, a type of single-celled protozoa, from the genus Mesodinium steal chloroplasts from their prey. They then use these chloroplasts to produce their own energy. Some even take nuclei to genetically transcribe more phototrophic machinery. Imagine if you could go outside and take some leaves form a tree and use that to gather sunlight for your dinner!
Dr. Ben Parker studied pea aphids, which have an incredible adaption to over-population. Pea aphids usually do not have wings, but if their environment becomes too crowded, they can produce offspring that do have wings. This allows the offspring to fly away to find a roomier home. Some aphids will also produce winged offspring in response to diseased plants, to allow dispersal to better resources. Dr. Parker also looked at the genetic variability in phenotypic plasticity in the aphid population. Some aphids will always produce winged offspring if the conditions are right, while others never do.
Finally, Dr. Daniel Schwab added some insightful perspectives to developmental plasticity. He explained that as organisms develop, they change in response to internal environmental conditions (such as nutrients and hormones) as well as external environmental factors. However, organisms are not passive or separate from their environments, but actively change their worlds by building homes or making tunnels. These environments changes that they create can in turn affect their phenotype. For example, dung beetles from the genus Onthophagus have polyphenic horns, meaning the size of their horns change in response to different conditions and relationships with the environment. These include available nutrients, hormones, symbioses with other organisms, and the type of burrows the beetle digs. Thus, the relationship between intrinsic and extrinsic factors is important to fully understand the horn plasticity in the beetles.
After the symposium, we enjoyed a reception back at the Natural History Museum, where we chatted with other scientists and checked out the exhibits. At last, we hit the road back to Earlham. Time for some sleep! And lots of homework…