Elements, genomes and ecosystems: cascading nitrogen and phosphorus impacts across levels of biological organisation

Andrew Leitch’s research has focused for over 20 years on the evolution of plant genomes, particularly in the context of polyploidy. Recently his interest has expanded to consider the huge range and skewed distribution of plant genome sizes, in particular to consider why some plant genomes have become huge, whilst others, the majority, have remained small, despite many rounds of paleopolyploidy in their ancestry. One potential reason why genomes are typically small is that there has been selection against enlargement imposed by limiting available nitrogen and phosphorus in the environment, a hypothesis which Andrew’s group currently investigates.

Maurine Neiman (bioweb.biology.uiowa.edu/neiman/index.php) is an Associate Professor in the Department of Biology at the University of Iowa. Her main research interest is a central unanswered question in evolutionary biology: why most organisms reproduce sexually even though asexual reproduction is much simpler and less costly. Much of her research program is focused on using genomic approaches to address the sex question in her snail system, the New Zealand freshwater snail Potamopyrgus antipodarum. Dr Neiman has led the effort to produce the first-ever genome assembly for these snails, and she is now using these genomic data to perform powerful tests of hypotheses for sex.

Dag O. Hessen is a professor in biology in the Department of Biosciences, University of Oslo. His main interests are stoichiometry at all scales, genome size evolution in animals, foodwebs and biodiversity as well as the role of dissolved organic matter on aquatic ecosystems. His current field of research is the interaction between P and the balance between RNA and DNA (genome size) at various time scales and models linking climate impacts on catchment export of DOC, N. P, Fe and Si (large scale stoichiometry). The balance of negative (light limitation) and positive (P) impacts on productivity is a major issue. Hessen has also written a large number of popular science books and papers on ecological and evolutionary issues and climate, including topics that encompass societal and philosophical issues.

Dr Jeyasingh and his students investigate the mechanistic links between ecology and evolution by quantifying the dynamics of elements at many levels of organization. Considering the content of the 25 elements represented in biology as quantitative traits expressed by species and genotypes within species, they generate evolutionarily explicit predictions about elemental excretion, and associated responses of key ecosystem services. Mass balance models guide deductive inference in: (i) systems that have been impacted by anthropogenic alterations to biogeochemical cycles, and (ii) taxa that have undergone rapid or replicated evolution. A variety of high-throughput methods (e.g., ionomics, genomics) are then utilized to uncover the biological mechanisms that are involved in mass balance at various levels of organization. Dr Jeyasingh received his PhD in 2007, and established his laboratory at Oklahoma State University in 2009 where he is an Assistant Professor.

Professor Weider received his B.S. degree from St. Bonaventure University (New York, USA) and his PhD from the University of Illinois at Urbana-Champaign. He spent five years in Canada as a postdoctoral researcher, and nearly 10 years at the Max Planck Institute for Limnology (now Evolutionary Biology) in Ploen, Germany as a Senior Research Scientist (tenured).  Since 1999, he has been a faculty member at the University of Oklahoma and served 13 ½ years as Director of the University of Oklahoma Biological Station located on Lake Texoma (OK-TX).  He is an evolutionary biologist/ecological geneticist who studies freshwater systems, with primary focus on the eco-genomic model organism, Daphnia. His research interests span a wide range of disciplines including biological stoichiometry, evolution in arctic freshwater systems, and resurrection ecology of long-dormant propagules.

Ilia Leitch is a plant evolutionary geneticist based at the Jodrell Laboratory, Royal Botanic Gardens, Kew with a focus on the consequences and evolution of genome size diversity across land plants. Her current research includes estimating, collating (e.g. the Plant DNA C-values database (http://data.kew.org/cvalues) and analysing data to provide insights into the evolutionary significance of the huge (nearly 2400-fold) range of genome sizes encountered in extant land plants. Of particular interest are the ecological consequences of the extensive genome size variation and what impact it has in determining where, when and how plants grow. Large scale analysis of the data held within the Plant DNA C-values database has enabled various ecological impacts to be analysed. Of particular relevance to this meeting is the finding that species occupying nutrient limited environments appear to be constrained in their genome sizes suggesting that macronutrients may play a role in determining the ecological habitat of a species.