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Scientific Programme

Full programme with abstracts available here.

CHA = Connecting habitats

CSB = Communication, symbiosis and behaviour

CSG = Chemosynthetic symbioses in the genomic and post-genomic era

EBC = Endophytism and biological control

EFM = Ecology and functionality of microbiomes (plants, vertebrates, invertebrates)

EMM= Establishment and maintenance of mutualism

FPM= Functional plant microbiomes: effects of endophytes and epiphytes on plants

HOL= Holobionts as players in ecological stress gradients

IAM=Interdisciplinary approach to mycorrhizal symbiosis 

LIS=Lichen symbionts: marriage, divorce, and domestic partnership 

MWH= Molecular and cell biology of Wolbachia-host interaction

NBS=Nematode-bacteria symbioses

REB=Reticulate evolution before and after the modern synthesis: historical and epistemological perspectives and wider applications beyond traditional fields

SBI= Symbiont-based improvement of plant nutraceutical value

SLS=Symbiotic lifestyle switching

SMI= Symbionts in multipartite interactions: ecology, evolution and regulatory mechanisms

STR=Strigolactones role in plant symbiosis in the rhizosphere

SYM= Symbiotic microbes - new frontiers in applied biotechnology 

TSY=Teaching symbiosis: look at successful strategies

PLEASE NOTE: This schedule may be subject to change

Plenary lectures

Dorion Sagan

“The evolutionary persistence of sex and aging - Why NeoDarwinists are wrong about group selection on a symbiotic planet”

Four billion years of evolution on a crowded planet have made life on Earth richer than accounted for in neo-Darwinism. In this talk I take a look at the new biology, focusing on aging and the need to re-introduce group selection to explain aging as an internal process. Looking at older views, including the very popular but factually flawed Free Radical Theory, as well as the more sophisticated and evolutionary theories begun by Sir Peter Medawar, I argue for a rapprochement between mainstream Darwinism and newer biological approaches with their focus on symbiosis, microbiome, and interspecies relationships. A new theory, better in accord with the facts—The Black Queen hypothesis, also the subject of a new coauthored book—better explains senescence. Like the Red Queen theories that have been accepted by neo-Darwinism to explain the persistence of meiotic reproduction, the Black Queen theory invokes selection at the population level. In this talk I will discuss the work of Lynn Margulis, my mother and writing partner for thirty years, as well as the neo-Darwinist William D. Hamilton and the lepidopterist (and novelist) Vladimir Nabokov. Sexual reproduction seems to have evolved from protist cannibalism, and perhaps been maintained in part because of the protection it afforded against epidemics. Likewise, senescence, evolving from apoptosis and replicative senescence in protists, seems to have been selected for its ability to mitigate dangerously fast population growth.

Rusty Rodriguez

“Wine, witches and wilderness: the sculpting of civilization by microbial symbionts”

The development of microbial photosynthesis 3.4BYA is theorized to be responsible for the accumulation of atmospheric oxygenic sufficient for aerobic respiration which began approx. 1-2 BYA.  That led to an explosion of biological diversity eventually resulting in the emergence of land plants and animals. Fossil records indicate that when plants moved onto land approx. 450 MYA, they were intimately associated with filamentous fungi.  Although Symbiosis was not defined until 1865 by Anton DeBary, there are many examples throughout history of how symbiosis sculpted civilization.  The symbiotic continuum spanning from mutualism to parasitism has collectively been responsible for some of the most beautiful and horrific events in history, each of which altered the future.  In recent times, it has become clear that symbiosis has also sculpted plant and animal life on earth.  Since DeBary’s remarkable description, it has become clear that all plants and animals are symbiotic with communities of microorganisms and that the vast majority of these interactions are non-pathogenic.  In fact, it appears that plants and animals can not survive without their microbial communities which play important roles in their ecology, adaptation, and fitness.  I will discuss how symbiosis has sculpted civilization through agricultural development, human behavior and ecosystem health, and the potential of symbiosis for future sustainability.

Catherine Masson

“Replaying the evolution of rhizobia: adaptation to the symbiotic lifestyle

The nitrogen-fixing legume-rhizobium symbiosis is an evolutionary novelty of extreme biological and ecological importance, as a major contributor to the global nitrogen cycle. Nowadays it is serving as a model for transferring nitrogen fixing capacities to non legume crops.

Rhizobia are remarkable examples of phylogenetically dispersed bacteria that, although achieving a complex biological function, arose via horizontal gene transfer of only a few key symbiotic genes in different genetic backgrounds. Rhizobia are currently distributed in hundreds species belonging to 13 saprophyte- and pathogen-containing genera of alpha- and beta-proteobacteria. Rhizobial mutualistic symbiosis with legumes is a complex process involving three main steps, nodule organogenesis, intracellular infection and nitrogen fixation. This endosymbiosis is controlled by a large number of genes in both partners including a set of essential nodulation and nitrogen fixation bacterial genes clustered in mobile genetic elements such as symbiotic plasmids or genomic islands. Successful transfer over large phylogenetic distances has been rare, likely because recruitment of bacterial functions and adaptation to the plant host need extensive genome reprogramming.

To get insights into the molecular and evolutionary mechanisms that facilitated the long distance spread of symbiotic genes, we experimentally replayed the evolution of rhizobia. Following introduction of the symbiotic plasmid of Cupriavidus taiwanensis, the Mimosa symbiont, into pathogenic Ralstonia solanacearum we challenged transconjugants to become Mimosa symbionts through serial and parallel ex planta-in planta (Mimosa) passages. This alternation recapitulated the shifts between free-living and symbiotic lives that have shaped the natural evolution of rhizobia. Evolution was surprisingly fast since the first two major symbiotic steps, nodulation and intracellular infection, were not only activated but also dramatically improved over 17 cycles (~400 generations) in all lineages. Evolution relied on many genomic changes and involved a mechanism of transient hypermutability that accelerates the symbiotic adaptation process under selection pressure from the host plant.

Jan Sapp

"The symbiotic self in a Darwinian world"


The classical one genome-one organism conception is giving way today to a symbiotic conception of the organism. Research on the importance of symbiosis as a source of evolutionary innovation has been carried out for over 100 years close to the margins of biology and in virtual conflict with biology’s central doctrines. In this presentation I shall explore why hereditary symbiosis and the microbial world were not included in the neo-Darwinian evolutionary synthesis of the last century. I will explore why recognition for the importance of symbiosis in evolution has emerged in recent years, how molecular phylogenetic methods applied to the microbial world have led to a conception of a universal web of life, based on horizontal gene transfer and symbiosis, which transcends Darwinian conceptions and contradicts its central tenets, and how the study of microbiomes have further reinforced the organismal conception of the symbiome.

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