We are transitioning to the University of Nottingham to join the School of Life Sciences and Future Foods Beacon of Excellence!
This will include two open PDRA positions for 2019.
We aim to understand how evolution finds solutions to tough circumstances, both environmental and intracellular. We do this by applying population genomics to wild populations that have overcome clearly definable, quantifiable hazards. That recent advances allow us to unambiguously identify candidate natural alleles underlying particular adaptations is revolutionary, making this a great time to apply population genomics to wild species.
By understanding natural solutions to important stressors — from tolerance of extreme levels of metal contamination, to the ability to thrive in high salt soils, to adaptation to the trauma of genome duplication — we will 1) inform an understanding of basic evolutionary processes and 2) help inform rational crop development to cope with a changing world.
Current research in the lab focusses on two adaptive challenges:
Genome Duplication. The most dramatic mutation is the duplication of an entire genome. Sudden genome doubling presents novel dynamics to the confined environment of the nucleus. How is this endured? Here’s what we’re learning.
Edaphic Extremophiles. We are focusing on adaptation to extreme soil conditions, from high salt soils to metal-contaminated barrens. The persistence of diverse species that can thrive in the face of these insults allows us to test for repeated evolution, flexibility of biochemical pathways, and constraint. Learn more here!
Recent talks, meetings:
Congrats to Silvia Busoms and our top collaborator Sian Bray – BOTH gave killer talks at SMBE in Yokohama in July!
Congrats to Christian Sailer, who spoke expertly at Evolution in Montpellier this August on our work on parallel evolution in Arabidopsis arenosa and Arabidopsis halleri.
Other than that Levi recently gave seminar in Oxford (May 24), CAS Beijing, China (July 4), The Kihara Instute, Japan (July 9), and University of Bern (Sept 17)
Several of us will be at PAG in Jan 2019 and of course popgroup!
Just accepted at PNAS: Busoms S, Paajanen P, Marburger S, Bray S, Huang X, Poschenrieder C, Yant L, and Salt D (accepted, PNAS) Ecological and population genomics reveals fluctuating selection on migrant adaptive sodium transporter alleles in coastal Arabidopsis thaliana
More on this soon; it will be freely available, open access as the final version following proofs.
Recently in Frontiers in Ecology and Evolution: The polyploid hop! The duplication of an entire genome is no small affair. Whole genome duplication (WGD) is a dramatic mutation with long-lasting effects, yet it occurs repeatedly in all eukaryotic kingdoms. Plants are particularly rich in documented WGDs, with recent and ancient polyploidization events in all major extant lineages. However, challenges immediately following WGD, such as the maintenance of stable chromosome segregation or detrimental ecological interactions with diploid progenitors, commonly do not permit establishment of nascent polyploids. Despite these immediate issues some lineages nevertheless persist and thrive. In fact, ecological modeling commonly supports patterns of adaptive niche differentiation in polyploids, with young polyploids often invading new niches and leaving their diploid progenitors behind. In line with these observations of polyploid evolutionary success, recent work documents instant physiological consequences of WGD associated with increased dehydration stress tolerance in first-generation autotetraploids. Furthermore, population genetic theory predicts both short- and long-term benefits of polyploidy and new empirical data suggests that established polyploids may act as “sponges” accumulating adaptive allelic diversity. In addition to their increased genetic variability, introgression with other tetraploid lineages, diploid progenitors, or even other species, further increases the available pool of genetic variants to polyploids. Despite this, the evolutionary advantages of polyploidy are still questioned, and the debate over the idea of polyploidy as an evolutionary dead-end carries on. Here we broadly synthesize the newest empirical data moving this debate forward. (open access link)
Recently in bioXriv: Pervasive population genomic consequences of genome duplication in Arabidopsis arenosa. This is the first population- and genome-wide empirical assessment of a body of theory stretching back to Haldane in 1930. We focus on the population genomic impact of autopolyploidy across a very recent (~20,000 generation) radiation. This is of fundamental, unique impact: there is a much empirical work on allopolyploids, which result from both hybridization and whole genome duplication (WGD), but no genome-scale empirical data investigating the population genomic consequences of autopolyploidy. Thus, we cleanly isolate the effects of chromosome copy number without the confounding effect of hybridization (open access link)
Recently in JEB: The more we look around in our data the more we see signs of adaptive introgression. Check out our recent review on genetic transfers between populations, closely related species, and even kingdoms. Here we discuss two major classes of these scenarios, adaptive introgression and horizontal gene flow, illustrating discoveries made across kingdoms. We are currently writing up some exciting cases of adaptive gene flow in addition to examples of repeated evolution. (open access link)
In PNAS: We used the wild Arabidopsis arenosa system to identify candidate genes underlying serpentine adaptation and found evidence that some selected alleles were borrowed from a related species while others were repeatedly involved in separate adaptation events in different species. This suggests that migrant alleles may have facilitated adaptation of a specific A. arenosa population to this multi-hazard environment and provides a set of strong candidates for interspecies adaptive gene flow. (open access link)