The Hilgendorf Lecture

09 November 2022 (Wednesday)

Host: Nico Michiels

Prof. Michel C. Milinkovitch (Dept of Genetics & Evolution, University of Geneva, Switzerland)

The Unreasonable Effectiveness of Reaction-Diffusion in Vertebrate Skin Colour Patterning

Alan Turing proposed a reaction-diffusion (RD) process as the chemical basis of morphogenesis. Despite the elegance of this model, its relevance for the precise description of morphogenesis in real organisms is largely disputed. I will discuss how mesoscopic properties of biological dynamical systems (including unsuspected subtle features) are captured by simple RD models without integrating the unmanageable profusion of variables at lower scales.

11 January 2023 (Wednesday)

Hosts: Todd Ehlers & Oliver Bossdorf

Prof. Dr. Thomas Hickler (Senckenberg Biodiversity and Climate Research Centre (BiK-F) and Department of Physical Geography at the Goethe-University of Frankfurt)

Interactions between biodiversity, ecosystem functioning and climate – past, present and future

Biodiversity loss and climate change pose enormous challenges for our society and are strongly interlinked. I will describe the numerous interactions between biodiversity, ecosystems and climate, including state-of-art future scenarios, in particular concerning the potential impacts of climate change on biodiversity, ecosystems and human well-being. These impacts are increasingly apparent already today and include more extreme weather, forest dieback, flooding and increasing risk for wildfires. Potential future changes are beyond our imagination and at the same order of magnitude as Earth System changes over tens of millions of years. This implies that paleo-research is crucial to understand the fundamental system behaviour and for developing reliable future predictions. Furthermore, both the biodiversity and the climate challenge need to be addressed together. Too much focus on climate only in the past has been harmful for biodiversity and often even detrimental to our climate goals.

13 July 2022 (Wednesday)

Host: Claudio Tennie

Prof. April Nowell (Dept. of Anthropology, University of Victoria, Canada)

The Stories We Tell: Children, oral storytelling, and knowledge transmission in the European Upper Paleolithic

Storytelling, whether around a campfire, in a café or a sold out theater, is ubiquitous in human culture. Globally, storytelling through film, television, books, videogames and other media represents a $300 billion industry. The universality of storytelling suggests that this behavior has deep roots. It also begs the questions of why we as humans find stories so compelling and what the evolutionary context for this behavior might be. The ways in which children learn in foraging societies differ from the classroom-based style of learning and teaching typical of industrialized societies in the West. This difference, however, has often been mischaracterized by anthropologists as an absence or rarity of direct teaching in foraging societies. In this talk, following the work of Scalise Sugiyama, I argue that oral storytelling is a form of pedagogy in foraging societies that shares  many of the features of direct teaching. Building on ethnographic data, I explore the evolutionary context, adaptive features and cognitive underpinnings of storytelling. I then present archaeological evidence for storytelling and narrative in the Upper Paleolithic. Finally, arguing that storytelling is a vehicle for cumulative culture, I consider the implications of this form of teaching for skill acquisition and knowledge transmission among Upper Paleolithic children and adolescents and for their role as drivers of human cultural evolution.

27 July 2022 (Wednesday)

Host: Susan Mentzer

Prof. Hazel Barton (Dept. of Biology, Integrated Bioscience, University of Akron, USA)

The Inherent Value of Cave Microbiology

Caves, by their nature, are aphotic and geologically isolated.  As such, it would seem that the microbial ecology of these environments would be of limited interest – populated by a few species adapted to the ultraoligotrophic conditions.  Yet caves contain a remarkable and varied microbial ecosystem that subsists on extremely low available nutrients. The absence of disturbance (such as diurnal, seasonal, or meteorological) allows us to study geochemical transformations that have been in equilibrium for thousands of years, revealing aspects of microbial physiology and energy conservation that are challenging to study elsewhere, including activity on the energetic fringes of the iron, manganese, and nitrogen cycles - and despite conditions considered aphotic, even photosynthesis.  In order to adapt to these unusual conditions, the microorganisms found in caves display unusual phenotypes, particularly regarding calcium chemistry and carbonate formation, which may play an important future role in reducing the carbon footprint of many industrial processes.

22 December 2021 (Wednesday)

Host: Hervé Bocherens

Prof. Dr. Kathryn Fitzsimmons (Department of Geosciences, University of Tübingen)

Note exceptional time: 17:30
Note exceptional location: lecture hall 3M07 of GUZ building (Schnarrenbergstraße 94-96)

The Silk Road and the Dreaming: interactions between climate, landscape and people on desert margins

The Earth’s land surface – its diverse landscapes – have provided our species with everything we need to survive. We, in turn, have adapted to changing landscapes, dispersed across continents, and thrived. The human story is a thrilling adventure played out over the last few million years, spanning the full range of ecosystems our world has to offer.
In this lecture I will take you on a tour of possibilities for integrating earth sciences with archaeological traces of human response to changing landscapes, with a focus on dryland environments. We will visit the desert margins of Australia (the Dreaming), where close cooperation between geologists, archaeologists and local indigenous people has uncovered evidence for preferential exploitation of lacustrine resources while the lakes were drying rather than when they were full, and for incredible human resilience in times of drastically reduced mobility due to lake filling. Moving to Central Asia (the Silk Road) and its substantial wind-blown dust (loess) deposits, we will explore the likely climatic contexts which formed the backdrop for hominin dispersals and interactions between multiple human species.
Each of these dramatic human stories took place against a geological backdrop of changing climates and landscapes which are most effectively reconstructed by integrating the earth science tools of geochronology, geochemistry, remote sensing, GIS and climate modelling, with archaeological enquiry. I will discuss exciting new approaches now available to extract more meaningful data from the terrestrial sediments which preserve past environments and their human stories.

30 June 2021 (Wednesday)

Host: Oliver Bossdorf
 

Prof. Camille Parmesan (Theoretical and Experimental Ecology Station in Moulis, Sète).

Note that this lecture (formerly scheduled on 23 June) has been postponed for one week.

This talk will be given online via Zoom.
 

Potentials and limitations of evolution in shaping the impacts of climate change on wild species

As climate change continues to accelerate, there is an emerging literature on population-level ecological and evolutionary responses that complement the large numbers of studies documenting species' range shifts. Localized responses can take the form of changes in dispersal behavior, voltinism, dietary specialization, camouflage, phenology or microhabitat choice. While studies of underlying processes often reveal variation based on plasticity, rapid changes can also be the results of rapid local evolution. These local changes are expected to differ qualitatively between expanding range limits and range interiors. Better understanding of the interplay between events at range limits and in range centers, and the extent to which plastic vs evolutionary processes prevail are important for conservation planning in the face of continued climate change. We highlight the highly climate-sensitive group of butterflies in the Euphydryas (North America) and Mellitae (Europe) groups to illustrate the complexity of possible population-level responses to climate change.

28 July 2021 (Wednesday)

Host: Korinna Allhoff
 

Prof. Fernanda Valdovinos (Environmental Science and Policy, University of California, Davis).

This talk will be given online via Zoom.
 

How ecological networks respond to environmental changes?

Plant-animal mutualistic networks sustain terrestrial biodiversity and human food-security. Environmental changes threaten these networks underscoring the urgency for developing predictive theories on the networks ’responses to perturbations.
This talk will present research conducted by my group and collaborators that seeks to understand the dynamics of ecological networks to inform predictions on their responses to environmental changes. In particular, I will present theoretical work predicting: i) foraging preferences of pollinators measured in the field, ii) invasion success and impacts on natives, and iii) interaction rewiring as response to a severe drought.
I will end my talk by briefly presenting examples of our work using ecological networks to study the response of food webs to fisheries.

09 Dec 2020 (Wednesday)

Host: Oliver Bossdorf
 

Prof. Marc T. J. Johnson, Ph.D. (University of Toronto, Centre for Urban Environments).

This talk will be given online via Zoom.
 

The Evolution of Life in the Urban Jungle

Urban areas represent the fastest growing ecosystem on earth, in which the development of cities dramatically changes the biotic and abiotic environment to create novel ecosystems. Despite the importance of urbanization, we have little understanding of how urbanization affects the evolution of species that live in cities. In this talk, I will discuss the most current science about how cities are affecting evolution in plants and animals, from elevating mutation rates to driving novel adaptions, to giving rise to new species through the process of urban driven speciation. I will then describe our research on a single model organisms, white clover, in which we have investigated whether urbanization affects natural selection, genetic drift, and gene flow. We are currently extending this work to understand if urbanization throughout the world is leading to convergent evolution at a global scale. I will conclude with a discussion of the applied importance of understanding evolution in cities.

08 Jan 2020
Host: Katerina Harvati

Prof. Dr. Ruth Ley (Department of Microbiome Science, Max Planck Inst. for Developmental Biology, Tübingen)

The role of the microbiome in human genetic adaptation

Human populations have adapted genetically to a variety of local environments across the globe. They have not done so alone, as humans harbour microbiomes acquired from other individuals and from the environment. A subset of host-associated microbes can affect host traits, and these microbes can also be under the genetic influence of the host. Microbiomes can thereby enable or otherwise affect the host’s adaptation to local environments. Our work has highlighted three examples where the microbiome has likely contributed to adaptive trait variation in humans. (1) The strongest association between gut microbiome composition and human genotype is between the human lactate gene (LCT) and the abundance of gut Bifidobacteria. This is true for multiple populations of European descent and is dependent on milk consumption. (2) We have also recently linked the variation in copy number of the salivary amylase gene (AMY1) with the composition and function of the gut microbiome. (3) The gut microbes for which humans have the strongest genetic predisposition belong to the family Christesenellaceae. Intriguingly, these bacteria are also associated with a lean human body type and can induce leanness in mice. Other known examples of local adaptations in humans exist, where future studies may investigate how microbes interact with host adaptive alleles in the process of host adaptive evolution. Despite the potential role of microbiomes in moderating host genetic adaptation, evolutionary models that integrate the interactions between beneficial microbes and beneficial host alleles during the process of host adaptation remain to be developed.

29 Jan 2020

Host: Oliver Bossdorf

Prof. Dr. Carol Lee (Centre of Rapid Evolution, Univ. of Wisconsin)

Note exceptional location (Hörsaal N10, Auf der Morgenstelle 3)

Rapid genomic evolution during habitat invasions

The ability of populations to expand their geographic ranges, whether as invaders, agricultural strains, or climate migrants, presents among the most serious global problems today. However, fundamental mechanisms remain poorly understood regarding factors that enable certain populations, such as biological invaders, to rapidly transition to novel habitats. According to one hypothesis, environmental fluctuations in the
native range could promote successful invasions in novel habitats by imposing balancing selection on key traits and maintaining the genetic variation that enables rapid adaptation. Here, we test the genomic
predictions of this hypothesis by performing whole genome sequencing of multiple independent invasive freshwater and native saline populations of the copepod Eurytemora affinis complex. We found that invasive populations have repeatedly responded to selection through the parallel use of the same SNPs and genomic loci, and remarkably, these same loci are enriched for signatures of long-term balancing selection in the native ranges. Our results support the hypothesis that fluctuating habitats can promote invasive success and that balancing selection could serve as a widespread and important mechanism enabling rapid adaptation in nature.