Dr. Kremer will give a keynote address on Thursday, August 28, for the IUFRO-CTIA Main Conference.  The abstract of his presentation is provided below.

What source and component of genetic variation is relevant for adaptation in trees ?
Lessons from phylogeography and population genomics in European trees

Research efforts in population and ecological genetics in trees were driven during recent years by conservation and adaptation issues. Central to the debate is the source and component of genetic variation that will actually contribute to the evolution of trees, and allow them to respond to future environmental change. I will review some of the results obtained in fields that have received major attention during the past ten years in population genetics (ranging from phylogeography to population genomics), and address how they changed or reinforced our views on genetic variation regarding conservation and adaptation issues. While traditional approaches allowed to estimate with reasonable accuracy the level of standing genetic variation, findings from phylogeographic studies permitted to elucidate evolutionary mechanisms that contributed to the extant distribution of variation. In contrast to North American species, European trees exhibit strong phylogeographic structures originating from the genetically isolated refugial zones where trees were confined during the glacial periods. Duration of separation in isolated genepools lasted long enough to allow genetic divergence, not only for neutral markers but also for adaptive traits. However past differentiation has not persisted in the extant populations in Central and Northern Europe, being erased by geneflow between admixed populations originating from different refugial zones and local selection. There is not footprint left in the todays’ distribution of genetic variation across temperate Europe. Hence genetic differentiation for adaptive traits is a consequence of evolutionary trends that lasted rather recently, during the Holocene, and phylogeographic patterns of variation will be of little value for conservation issues. Exception to this is the Mediterranean region, where genetic differentiation was preserved even during recolonisation, and local populations may deserve conservation measures.

More recently genomics has allowed to investigate the genetic basis of adaptive variation, by identifying genes of adaptive significance. While the body of results is still scarce, populations surveys in gene frequencies indicate that their level of differentiation is far from reaching the level of differentiation of the adaptive traits measured in provenance tests. Interestingly this discrepancy is expected by theoretical predictions. Indeed the genetic variation of a complex trait is composed of two components: the genetic differences at the gene level (that can be detected by gene sequences and measured as Fst) and the association of alleles at the different genes controlling the trait (that corresponds to disequilibria among genes). Theoretical investigations suggest that for traits depending on many loci and for species with high gene flow as trees, differentiation of genes will remain at levels close to neutral expectations, while association of alleles will represent the major component of differentiation of the adaptive trait. If these results are confirmed by future experimental data, they will lead to important consequences in conservation issues. As Fst is low, the basis for evolutionary potential can be sampled within a very few number of populations, and future adaptation will proceed by associating alleles differently according to selections pressures.

• Senior Research Fellow at INRA “Institut National de la Recherche Agronomique”
  
  
• Director of the Joint Research Unit BIOGECO « Biodiversity, Genes & Communities », INRA and University of Bordeaux 1
  
  
• Coordinator of the European Network of Excellence EVOLTREE “Evolution of Trees as drivers of terrestrial biodiversity”
  
  

RESEARCH INTERESTS

My main research interests address the evolution of genetic diversity and differentiation between natural populations in trees, at various hierarchical levels where diversity is expressed (from genes to phenotypic traits). My research combines theoretical and experimental approaches. An important goal is to gather population data at various spatial and geographic scales to describe and dissect population differentiation, and to depict general distribution patterns. These data are then compared to theoretical predictions obtained by analytical derivations or simulations, where various different evolutionary scenarios are tested.

EDUCATION

• 1976 : Forestry Engineer Degree, Ecole Nationale des Ingénieurs des Travaux des Eaux et Forêts (ENITEF)
  
  
• 1992 : Ph.D. in Quantitative Genetics at University of Paris XI-Orsay
  
  
• 1995 : Habilitation Degree in Population Genetics at University of Paris XI-Orsay
  
  

SCIENTIFIC CAREER

• 1976-1979 : Assistant research fellow at INRA
  
  
• 1980-1981 : Visiting scientist at USDA (Forestry Sciences Laboratory, Rhinelander, WI)
  
  
• 1982- 2000 : Research fellow at INRA – Forest Genetics Laboratory at INRA Cestas
  
  
• 2000- 2001 : Head of the French Institute for Biodiversity (Institut Français de la Biodiversité)
  
  
• 2003 -        : Acting director of the Joint Research Unit “Biodiversity Genes & Communities” INRA-University of Bordeaux 1
  
  

AWARDS

• 1995 : Scientific Achievement Award of IUFRO (International Union of Forest Research Organizations)
  
  
• 2003 : European Forest Research Award by the Foundation for European Forest Research
  
  
• 2006 : Marcus Wallenberg Prize