My first publication, as second author, is a resurrection study. It is an investigation into the impact of the 2012-2016 drought in California on natural populations of Erythranthe laciniata, the cutleaf monkeyflower. A former student in the Sexton lab, Erin Dickman, who graduated with her Master's degree the year before I started graduate school pioneered the experiment. She grew the first experiment of monkeyflowers and recorded any differences between the generations. To bolster the publication of her results, I grew a second experiment and recorded the same data.
The basic results are these: When grown in a common environment with plenty of water and a mild temperature, data from nine populations reveals that the drought generation plants, grown from seed collected in 2014, germinate and flower earlier than non-drought generation plants, grown from seed collected in 2005. This signals a rapid evolution event, as the population level average day to germination and flowering is different between two generations for the same population. These results held between both the experiment Erin ran and the one I ran, further signaling a genetic change. That is to say-- the change in trait averages held through the two breeding experiments.
Now, what to do with this information? For my dissertation, I need at least three chapters. The first chapter is a meta-analysis of experiments that record quantitative genetic variation patters between populations of any species. Check. What about the other two? My advisor Jay always said that field experiments are a time-honored, classic, and robust method to measure differences in plant populations. So a field experiment I shall do.
This is low-key the nitty-gritty of my field experiment. Also, this is a pilot experiment. The nuts and bolts, if you will. I'll try and make it clear, but it may be tedious and boring. I think it's fun though~
With the seeds from the resurrection experiment in hand, I design my field experiment. I have nine populations, three each from low, medium, and high elevations across the range of the cutleaf monkeyflower. That means I can test local adaptation-- if populations are adapted to their local climate or not. Implementing three gardens, I can test if, for instance, if high elevation populations grow better in high elevations, or if they actually grow better at a lower elevation.
I also want to test if drought generation populations grow better than non-drought generation populations in contemporary conditions-- especially in contemporary drought conditions. I would expect the drought generation to have higher fitness (produce more seeds) than the non-drought generation in contemporary drought conditions, but if the water year is average or above I would expect the drought generation to have similar or reduced fitness than the non-drought generation.
Further, I am interested in quantitative genetic variation (QGV). This is the variation in traits found in a population. For instance, for the height of plants, a population with high QGV in the height trait would have a lot of different plant heights. Conversely, a population with low QGV in height trait would have a lot of plants of a similar height. That's a basic breakdown of QGV. It is of interest to me because it is theorized that populations with high QGV will be more able to adapt to changing conditions. They will be more likely to have plants that have traits that can survive whatever the change is, and those plants will survive and thrive.
To measure QGV in a self-fertilizing plant like the cutleaf monkeyflower, you need family level measurements of traits. So, multiple measurements from the same family, multiple sets of the same seed grown in the experiment. For my field experiment I have five families from each population replicated three times at each garden. This will show me if and how QGV varies between populations, elevations, and generations.
This is the gist of my experiment. I sowed the seeds in the Fall semester 2019 and implemented the high and middle gardens in November and the low garden in January, so they could germinate in the wild over winter with the natural populations.
But what happened in 2020?
Field work during a pandemic is tough. Firstly, it's very nerve-wracking to start going out to visit gardens when it's unclear exactly how the virus is spread. Even going to get gas is potentially hazardous. Nevertheless, I persist. Armed with hand sanitizer and my field assistant girlfriend, I conducted a field experiment all through the pandemic.
And what happened with the experiment?
Well.. it did what pilot experiments do.
I had some success at the low garden. Some trays didn't germinate but overall I was able to collect good data. And only one tray was flipped over. And only one tray was pooped on.
The middle garden was the most successful, but over half the trays got crushed underneath the snow.
The high garden was a disaster, with trays either completely dry or completely overgrown. Or completely crushed.
So what now? Well, the true field experiment will commence in 2021. True as in not a pilot. And not another pilot because, well, I really must graduate at some point.
Til next time~