The Dlugosch Lab @ The University of Arizona

Dlugosch Lab Research

We study the genetics of colonization and its evolutionary and ecological outcomes. Our work draws largely on the natural experiments provided by human-mediated species introductions and we are working to understand how the genetic variation in these populations translates into phenotypic diversity, adaptation, and changes in ecology.  Major themes in the lab include:
In addition, students in the lab are encouraged to explore their own directions. See more about what they are doing on our People page!

Distribution of genetic variation during colonization: bottlenecks & admixture 

It is a simple truism that evolution requires genetic variation. For colonizing populations, the source(s) of individuals and genes that contribute to a new population will determine its raw material for future evolution. Among introduced species in particular, genetic bottlenecks are expected, but mixing of material from different source locations and hybridization with related species are hypothesized to enhance adaptation and establishment success. Nevertheless, we still know little about how often or how much these processes actually contribute to adaptive variation in founding populations, and whether intra- or inter-specific hybridization results in novel traits that are not already found in the initial source of an introduction. Using genomic scans and phenotypic surveys, we are exploring bottlenecks, admixture, and inter- and intra-specific hybridization in invasive species.

Genetic basis of adaptation & sources of adaptive variation for colonizers

We have observed evidence of adaptation in recently introduced populations that have experienced strong genetic bottlenecks, highlighting the need to understand how genetic architecture makes such rapid evolution possible. 'Next-generation' sequencing technologies are providing the opportunity to begin making the connection between rapid phenotypic evolution and its molecular genetic basis in non-model organisms. We are using cutting-edge genomic and bioinformatic approaches to map the genetic basis of evolving traits, to track the sources of adaptive alleles, and to infer the ecological functions and genetic trade-offs that might be under selection during colonization. Much of this work revolves around studies of the highly invasive plant yellow starthistle (Centaurea solstitialis). We have shown that invading genotypes have evolved a novel increase in growth that has a positive effect on fitness, and we are using classical genetic mapping approaches to understand the genetic changes underlying evolution in this invasion (USDA grant #2015-67013-23000).

Impact of adaptation on demography & the evolution of 'invasiveness'

There is a growing appreciation that adaptive evolution might contribute directly to invasive behavior in introduced species, allowing them to overcome environmental obstacles and exploit ecological opportunities. Nevertheless, adaptation is a process of relative changes in the fitness of different lineages, and this may have little impact on vital rates in the population overall. We are working to make links between genetic variation, adaptation, and ecology by following the demographic performance of different genotypes in several contexts:
  • Together with David Baltrus and Sarah Swope, we are investigating the fitness effects of microbial interactions between the highly invasive plant Centaurea solstitialis, and we will be scaling these effects up to population impacts using demographic models (USDA grant #2015-67013-23000).
  • Together with collaborators Bill Morris, Dan Doak, and Cynthia Hays, we are studying the contribution of local adaptation to population persistence during climate change in a native species, the alpine plant Silene acaulis.
  • We are currently planning experience that will use the experimental landscapes inside of Biosphere2 (via the Landscape Evolution Observatory project) to study experimental evolution and its demographic effects.
  • Together with Mike Barker, we have recently been funded to explore the connections between gene expression and demographic success (NSF EAGER-NEON #1550838). We will use comparative work among diploid, polyploid, and invasive species to test for the genomic and population level effects of variation in both genome structure/content and in the origins of species in a community in the NEON long-term research network. Check out our progress HERE!

All contents \A9 copyright 2011-2017 Katrina M Dlugosch