Researchers are trying to understand how changes in the environment lead to changes in organisms. For example, how do warmer spring and summer days affect how well the caterpillar of a common Washington butterfly grows? One way to answer this type of question is by repeating an old experiment years later to see how results have changed over time.
Lauren Buckley, University of Washington professor of biology, recently had the opportunity to organize a special issue of The American Naturalist featuring papers that use these types of “functional resurvey” experiments to answer questions about a variety of organisms, from bacteria to plants and animals. For example, one study explores resurrecting flower seeds to reveal evolutionary responses to drought. Another compares the genetics of coral reef fish preserved in rum in 1908 to these same fish now to examine how populations changed over the past century.
UW News spoke with Buckley about these experiments and what they can tell us about how organisms change over time.
What are the benefits of repeating historical experiments?
Lauren Buckley: As environments shift, species are migrating, changing in abundance and interacting with new species in response. But we lack effective strategies to anticipate these changes and plan for impacts to agriculture, disease and biodiversity. Repeating historical experiments reveals the processes underlying biological responses and should allow us to improve our ability to predict what will happen in the future.
Are there any drawbacks involved in these experiments?
LB: Replicating methods based on the descriptions in published papers can be difficult. We also face challenges, such as working with poorly preserved data or specimens, or trying to control for other changes that have happened over time — for example, Seattle is drastically different than it was 25 years ago. Knowing the best time to repeat an experiment is also a challenge, but wait times can be surprisingly short for organisms with short life cycles, such as bacteria.
Our current work is uncovering evolutionary changes in Washington butterflies after 25 years. This research is made easier because we are collaborating with the original researcher, who is 25 years older than me. We joke that the undergraduate researchers, who are 25 years younger than me, are expected to repeat the study again in 25 years.
How common is this technique?
LB: When I was looking for examples of functional resurvey experiments to include in the special issue, I was surprised to find that not many people use the approach. Many of the experimental approaches that we think hold the most promise for repeating are now decades old — perfect timing to be repeated. Also, the accelerating environmental change over recent decades has rapidly expanded opportunities for more of these types of experiments. I hope more scientists will be inspired to use this technique.
Functional resurvey experiments can be great fun! It’s exciting to plot new data against past experimental results and, despite our best efforts at improving predictions, we are often surprised by the biological changes. We get to see evolution happening, but not necessarily in the way we expect.
For more information, contact Buckley at buckley@uw.edu.