Research

1. Speciation and fitness landscapes 

A fundamental question in evolutionary biology is how species arise and how reproductive isolation is generated. A major focus of our group is on the ecological and genetic mechanisms underlying reproductive isolation and speciation in the genus Antirrhinum (snapdragons). We use hybrid zones as 'natural laboratories' to search for genotype-phenotype associations, estimate selection and where barriers operate along the genome. Using a long term pedigreed population, quantitative genetics, molecular genomics and new theoretical approaches we aim to learn how the genes determining yellow and magenta species arose in the past and how they generate barriers to gene flow today. 

1) which genes contribute to reproductive isolation?

2) where are barriers to gene flow situated along the genome?

3) what is the structure of the fitness landscape?

Snapdragon work funded by Austrian Research Fund (FWF) (2019-2023). Collaboration with Nick Barton (IST Austria) and Enrico Coen (John Innes Centre UK). 

Representative publications

• Tavares H, Whibley A, Field DL, Bradley D, Couchman M, et al., (2018). Selection and gene flow shape genomic islands that control floral guides. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.1801832115 

• Ellis TJ and Field DL (2016). Repeated gains in yellow and anthocyanin pigmentation in flower colour transitions in the Antirrhineae. Annals of Botany. 117 (7): 1133-1140 

2. Genetic and biochemical basis of flower colour

In both Snapdragons and Kangaroo paws a major aim is to identify the molecular genetic basis and biochemical pathways responsible for flower colour.  We are also working on the genetic basis of colour differences in Anigozanthos (Kangaroo Paws) and the biochemical basis of these differences across the genus.

1) which genes contribute to reproductive isolation?

2) where are barriers to gene flow situated along the genome?

3) what is the structure of the fitness landscape?

Kangaroo paws funded through Australian Research Council (ARC) (2022-2025).

Representative publications

• Bradley D, Xu P, Mohorianu I, Whibley A, Field DL, et al., (2017). Evolution of flower colour pattern through selection on regulatory small RNAs. Science. 358: 925-928 

3. Genetic and evolutionary rescue of threatened species

One of the most hotly debated topics in population and conservation biology is: what is the best genetic strategy for assisted migration, restoration and supplementing small and endangered populations? Here we are building theoretical models and experiments to understand how genetic architecture impacts restoration and assisted migration strategies. We are developing a range of modelling approaches, experiments in the lab, combined with genomic approaches to elucidate when to 'mix and match' and when to keep populations separate. 

Collaboration with Melinda Pickup and Himani Sachdeva (University of Vienna), Nick Barton (IST).

Representative publications

• Pickup M, Field DL, Rowell, D.M, Young, A.G (2013) The importance of source population for heterosis in fragmented plant populations. Proceedings of the Royal Society B, 280: 20122058 

4. Hybridisation and plant mating systems

Plant exhibit a remarkable diversity of reproductive strategies and mating systems. The ecological and evolutionary conditions favouring transitions between different systems, how they drive life history traits and the consequences for reproductive barriers between populations have long puzzled researchers in the field. We address a range of topics related to this area including; (i) models of the diversification of self-incompatibility, (ii) sexual dimorphism, (iii) barriers to gene flow and mating systems, (iv) hybridisation and invasions. With Katka Bodova, Nick Barton, Melinda Pickup, Christelle Fraisse, Yaniv Brandvain and others.

Representative publications

• Pickup M, Brandvain Y, Fraisse C, Yakimowski S, Barton N, Dixit T, Lexer C, Careghetti E, Field DL (2019). Mating system variation in hybrid zones: facilitation, barriers and asymmetries to gene flow. New Phytologist

• Bodova K, Priklopil T, Field DL, Barton N, Pickup M (2018). Evolutionary pathways for the generation of new self-incompatibility haplotypes in a non-self recognition system. Genetics. 10.1534/genetics.118.300748 

5. Evolutionary and population genetic theory 

A major goal of our group is to quantify crucial evolutionary and demographic parameters (e.g. selection, heritability, dispersal). This knowledge is also of importance more broadly in evolutionary and conservation biology, and to plant breeding and global food security. To that end, we also develop new programs for population genomic analyses including (i) genomic scans of geographic clines, (ii) dispersal in polyploids and (iii) pedigree/sibship inference. 

Representative publications

• Ellis TJ, Field DL, Barton NH (2018). Efficient inference of paternity and sibships given known maternity via hierarchical clustering. Molecular Ecology Resources. https://doi.org/10.1111/1755-0998.12782 

• Field DL, Broadhurst LM, Elliot C, Young AG (2017). Population assignment in autopolyploids. Heredity. 119: 389-401. 

• Ringbauer H, Kolesnikov, A, Field DL, Barton NH (2018). Estimating barriers to gene flow from distorted isolation by distance patterns. Genetics. 10.1534/genetics.117.300638.