I’m excited by recent advances in our ability to see clear signatures of selection in natural populations in response to intense selective pressures. Examples we are currently working on include adaptation to whole genome duplication and extreme edaphic conditions, such as lead, zinc, and serpentine soil tolerance.
We are particularly interested in the repeatability of evolution in response to genome duplication. Understanding how the cell adapts to the radical upheaval of doubling chromosome complements in a single generation reveals new biology that traditional mutant screens, for example, do not illuminate. We are therefore performing focused genome scans of many independently derived autopolyploid species to test for within- and between-species repeated evolution. See more about these projects here.
Another major focus of the lab is to understand repeatability and constraint of other adaptations, such as adaptation to phytotoxic metal levels or low nutrient conditions. For this project, we are scanning separate cases of serpentine and heavy metal-tolerant populations in the Brassicaceae. Thus far, we have seen striking cases of repeated evolution in response to serpentine challenge, as well as high levels of inter- and infraspecific gene flow and selection on introgressed alleles. Check out more here.
Results from these projects providing clear parallels across kingdoms, but also rather surprising differences, providing fruitful inroads for detailed functional analyses of the consequences of genome evolution. Our overall goal is to understand how the cell adapts to the sudden upheaval by investigating many independently-evolved natural solutions to these stressors. Initial results have surprised us by indicating that even conserved meiotic processes are capable of nimble evolutionary shifts when required.