Dr Barbara Anderson
Dr Nick Mortimer - Baylis Lecture
GNS, Botanical Society of Otago and Department of Botany
Hybridisation, genetic pollution and speciation in Eucalyptus
Eucalypts dominate Australian forests and woodlands, making them one of the most ecologically important plant groups on the continent.
There are over 900 eucalypt taxa, and interspecific hybridisation is common between closely related species. This propensity for hybridisation has led to concerns about genetic contamination (genetic pollution) of native forests by “locally exotic” plantation eucalypts following a massive expansion of the plantation industry in southern Australia between 1995 and 2010. I’ll discuss work undertaken during my PhD that aimed to understand the risk of gene flow between plantation and native eucalypts.
This involved analysis of reproductive barriers including assaying phylogenetic patterns of cross-compatibility. This phylogenetic approach combined with detailed case studies allowed me to show that while the overall risk of genetic contamination is low, there are at-risk linages and certain situations where gene flow is more likely.
Although this research was applied in focus, it also led to some fundamental insights into the mode and tempo of speciation in Eucalyptus. In particular, we found some of the first empirical evidence that the rate of cross-incompatibility accelerates relative to genetic distance, as has long been predicted by theory. This points to an important role for epistasis (outbreeding depression) in maintaining species integrity, and my help explain the persistence of clear species boundaries between naturally co-occurring eucalypts.
Professor Indrawati Oey
Department of Food Science, University of Otago
Maintaining food supply and integrity from farm to fork
Dr Chris Brown
Department of Biochemistry, University of Otago
Noncoding RNAs and the complexity of genomes.
Noncoding RNAs play many roles in cells from all domains of life. They contribute to the complexity of eukaryotes and the adaptive immune system of prokaryotes. We have been developing and applying bioinformatic approaches to discover and characterise ncRNA, alongside protein coding genes, in genomes and transcriptomes.
In this seminar I will describe exemplars of non-coding RNAs we are studying- several with collaborators. These RNAs have diverse roles in cells. In prokaryotes we are characterising the RNA mediated adaptive immune system (CRISPR-Cas). In the beneficial plant fungal endophyte (Trichoderma virens) we are determining the role of ncRNA riboswitches in thiamine regulated gene expression.
Thursday 19th May
Associate Professor Richard Gill - William Evans Fellow
Department of Biology, Brigham Young University
Physical and Biological Filters to Species Expansion: Niche Opportunity in Subalpine and Desert Ecosystems.
Richard Gill developed an interest in ecology as a child while exploring the forests and seashores of Washington State in the US. His research focuses on global change ecology, studying the impacts of changes in atmospheric CO2, temperature, and drought on community and ecosystem processes. He is currently an Associate Professor at Brigham Young University and is on leave at the University of Otago and Landcare to examine the links between evolutionary history and plant physiological traits in NZ tussock grasses.
In this talk, he will report on the results of two large global change experiments in the subalpine zone of the Rocky Mountains and two US deserts.
Thursday 5th May
Greg Nelson, PhD candidate,
Department of Botany, University of Otago and Landcare Research
Ecology and Evolution of the Genus Chionochloa
Understanding how ecological processes produce new species is a core interest in biology. Whereas, macroevolutionary studies between genera and/or between geographic regions inform large scale patterns, it remains difficult to tease apart specific mechanisms driving these patterns. Therefore, compiling cases studies at the generic level is an important step towards understanding the underlying mechanisms involved in diversification. Focusing on the genus Chionochloa - genetic, functional, and distributional data are combined to provide an in depth picture of the ecology and evolution of the group. Bayesian phylogenetic tree construction, Ornstein-Uhlenbeck evolutionary trait optimum analysis, and species distribution models are used, respectively, to investigate the evolutionary narrative of the genus. Results suggest that the development of the novel trait called dehiscence, or the ability to drop dead leaf material, was an important evolutionary feature that allowed the group to establish in previously inaccessible environments. Moreover, trait similarity was a better predictor of niche overlap than phylogenetic relatedness. This suggests that adaptation to local environments can happen rapidly and divergent selection is an important feature driving diversification.
Thursday April 7th
Esther Dale, PhD candidate, Department of Botany, University of Otago and Landcare Research
Do biome shifts promote lineage diversification?
Eco-evolutionary processes involved in lineage diversification are poorly understood. Strong niche conservatism often limits speciation within single biomes. Despite this, some radiations occur across a range of habitat types and bioclimatic zones. My research focuses on lineage diversification in woody groups to understand how evolutionary processes, traits, niche characteristics and biome occupancy influence patterns of speciation. In New Zealand I am investigating three genera (Myrsine, Melicytus and Pseudopanax) that span forest and more open habitats. I have begun compiling data on physical traits, tolerance traits and species distributions to test the role of key innovations in diversification within and across biomes. Preliminary trait data indicate species niches are closely linked to biome in some lineages, while others have a strong phylogenetic signal. I am also using a species-rich woody genus in Australia to determine the relative importance of within and across biome diversification in lineage evolution. Integration of niche modelling, traits, phylogenies and biomes combines ecology and evolution to understand extant diversification patterns in woody genera.
Thursday, March 3rd
Dr Will Cornwell, Senior lecturer, University of New South Wales, Australia
What we (don’t) know about global plant diversity
Global biological databases have two goals: organizing data in such a way that future research projects can target new angles with access to decades of accumulated data, and providing the best global picture of biodiversity available at a given time. We now know more than we have ever before, but compared to the vastness of global biodiversity we still do not know very much, and it is worthwhile, periodically, to take stock of what information we still lack. How much do we know about global plant diversity, and what and where are the most conspicuous blank pages in our encyclopedia of plant life?
More info at www.willcornwell.org