Every semester, EES organise a seminar series, which takes place on Mondays at 16:00 at Biozentrum, Großhaderner Str. 2, 82152 Planegg-Martinsried, Lecture Hall B 01.019
Speakers are invited from mainly around Europe across all three areas (Evolution, Ecology and Systematics), leading to a wide-range of presented research topics.
Winter Semester 2022/23
Cristina Tuni -Reproductive trait evolution: unravelling the effects of pre- and post-copulatory sexual
selection. (ONLINE ONLY)
University of Torino, Italy
Abstract: Sexual selection operates both before and after mating, with evolutionary theory predicting that traits involved in mate acquisition, namely pre-copulatory traits, covary with those involved in fertilization success, namely post-copulatory traits. Based on the nature of these associations, selection acting on traits, such as male ornaments and/or armaments, can potentially constrain or facilitate the evolution of other traits, such as testes and/or sperm phenotype, and vice-versa. Using the field cricket Gryllus bimaculatus as a model system, my research aims at understanding how pre- and post-copulatory sexual selection shape complex reproductive phenotypes. I will
discuss findings from studies uncovering both, phenotypic and genetic correlations among behaviour, morphology, and ejaculate traits, suggesting that traits are integrated at the genetic level. I will further report on a long-
term experimental evolution study designed to disentangle the effects of pre-and post-copulatory selective pressures on a range of reproductive traits. The study of male courtship singing, aggressiveness and weaponry (mandibles), testes and sperm traits, will allow understanding whether and which traits diverge in response to altered pre- or post-mating selective pressures, potentially shedding light on correlated evolution and/or evolutionary trade-offs between reproductive traits.
R. Brian Langerhans - Predictability and parallelism of multi-trait adaptation and speciation.
North Carolina State University, United States of America
Abstract: Environments shape the traits of organisms and appear to ultimately cause the majority of speciation on Earth. While the deterministic action of selection on organismal phenotypes is widespread, the degree to which evolutionary change might be predicted (from theory) and the magnitude of parallelism (consistent occurrences) during evolution is not yet well understood. Using the post-Pleistocene radiation of Bahamas mosquitofish (Gambusia hubbsi) inhabiting blue holes, I assess the predictability, parallelism, and magnitude of evolutionary divergence in nearly 100 traits and six reproductive isolating barriers. Natural selection clearly drives a non-trivial amount of
predictable and repeatable evolution, directly influencing the evolution of multiple isolating barriers during speciation. But just how predictable and consistent are these patterns, how generalizable are the results, and what explains all of the “unexplained” phenotypic evolution and reproductive isolation?
Carolin Haug -Quantifying convergent evolution: examples from “flying crustaceans”
LMU Munich, Germany
Abstract: Animal life appears almost unlimited in overall form variation,yet we see repetitively the same shapes evolving independently. This phenomenon is generally addressed as convergence. Besides the fact that convergence is widely recognised as “similar morphologies in distantly related lineages”, the question often remains: how similar is similar? I present several cases of convergence within the group Insecta
using quantifiable characteristics of specimens from the modern fauna and the fossil record. Especially apparent are
similar morphologies due to similar selective pressures for grasping and holding prey items. I demonstrate that using
fossil and extant representatives of numerous distantly related lineages in a frame of quantifiable traits offers the detection of cases of convergent evolution and evolutionary processes behind it.
Anja Hörger -Constraint or opportunity? How trade-offs in stress adaptation may facilitate the evolution of heavy metal hyperaccumulation in plants
Paris-Lodron-University Salzburg, Austria
Abstract: Metal hyperaccumulating plants are able to accumulate exceptionally high concentrations of heavy metals in their shoots to levels that would be toxic to most other plant species. This trait has evolved independently multiple times in the plant kingdom. Although our understanding of the molecular mechanisms involved in metal uptake and tolerance has improved, not much is known about the processes that have led to the evolution of metal hyperaccumulation in plants. Recent studies have provided new insight into the ecological
and evolutionary significance of this trait by showing that the metal hyperaccumulatingplant Noccaea caerulescens can use high concentrations of accumulated metals to defend itself against attack by pathogenic microorganisms and/or herbivores. Interestingly, attacked N. caerulescens plants seem compromised in the inducible defence responses that are used by most plants to provide protection against antagonists, which suggests that it
relies on accumulated metal for resistance. The fact that these plants have evolved the ability to uptake and store metals in their shoot tissue, but have in turn lost defences common to most plants suggests a trade-off in expressing both traits. We studied physiological, molecular and ecological processes involved in the gain of metal
hyperaccumulation and loss of other defensive traits in N. caerulescens. Genes involved in the trade-off were identified and analysed using a combined phenotyping and transcriptomics strategy. Our results provide new insights into the evolution and ecology of metal hyperaccumulation and contribute to the understanding of how plant adaptation to biotic and abiotic stress may be connected.
Aurélien Tellier - Inference of ecological and life-history traits from full genome polymorphism data: tales of success and limitations
Technical University of Munich, Germany
Abstract: While most inference methods using full-genome data can be applied to all possible kind of species, the underlying assumptions are often sexual reproduction in each generation and non-overlapping generations. However, in many plants, invertebrates, fungi and other taxa, those assumptions are often violated due to different ecological and life history traits, such as self-fertilization, long term dormant structures (seed or egg-banking) or large
variance in offspring production. Furthermore, the resolution of past inference decreases when there is a lack of SNPs in the data. I will present here three new developments of the Sequentially Markovian Coalescent (SMC) and Deep Learning (DL) methods based on Graph Neural Networks (GNN) allowing us to 1) infer seed banking / dormancy or selfing rates and their change in time, 2) infer the variance in offspring production and regions under positive selection along the genome, and 3) integrate epigenetic (methylation) markers to improve the inference of past events.
Krushnamegh Kunte - The Evolution and Genetics of Butterfly Wing Colour Patterns
National Center for Biological Sciences, Bangalore, India
Abstract: Butterflies use colours in many aspects of their lives: from keeping warm in cold climates to evading predators and impressing potential mates. In this talk, Dr. Kunte will narrate scientific discoveries on how butterfly colour patterns have diversified under natural and sexual selection, how genetic variation and genomic architecture facilitate colour pattern diversification, and how the patterns are regulated during development through co-option and other means. Thus, this talk will bring to the audience a unique appreciation of the evolutionary patterns and genetic mechanisms by which butterflies get their brilliant colours.
Summer Semester 2020
Björn Benning - Bryozoa in a nutshell: evolution, ecology, systematics
Oberösterreichisches Landmuseum Linz, Austria
Virginie Courtier-Orgogozo - Evolution of Drosophila Bristles
CNRS, Paris, France
Douglas Sheil - Forests and Water: Advances and Controversies
Norwegian University of Life Sciences
University of Cambridge, UK
Winter Semester 2019/20
Alistair McGregor - Investigating the Evolution of Developmental Regulation in Spiders and Flies
Oxford Brookes University, UK
Abstract: Research in my lab focuses on questions that are key to understanding animal evolution: How does the genetic regulation of development evolve and what is the genetic and developmental bases for morphological variation within and between species. To address these questions we study the genomics and genetics of the development of the spider Parasteatoda tepidariorum, and gene regulation and morphological evolution among flies of the Drosophila melanogaster species subgroup. In this talk I will present our recent work on the regulation of segmentation in Parasteatoda, and on investigating cis-regulatory logic and morphology evolution among Drosophila species. Research in my lab focuses on questions that are key to understanding animal evolution: How does the genetic regulation of development evolve and what is the genetic and developmental bases for morphological variation within and between species. To address these questions we study the genomics and genetics of the development of the spider Parasteatoda tepidariorum, and gene regulation and morphological evolution among flies of the Drosophila melanogaster species subgroup. In this talk I will present our recent work on the regulation of segmentation in Parasteatoda, and on investigating cis-regulatory logic and morphology evolution among Drosophila species.
Marie Herbestein - Unlocking the paradox of imperfect mimicry using ant mimicking spiders
Macquarie University, Australia
Abstract: Batesian mimics are deliciously palatable species that gain protection from a predator by resembling a defended or unpalatable model. Theory predicts that mimics that closely resemble their model should have the greatest advantage, while inaccurate mimics should be recognised and attacked by predators. This is all fine and good, but in reality, we find that mimics are highly variable, some are excellent in mimicking their model and others are rubbish at it. There are many different hypotheses that try to explain the persistence of inaccurate mimics, and we have a research project at Macquarie University that tests these ideas using ant mimicking spiders. In this seminar, I will illustrate the range of mimic fidelity in ant mimicking spiders and present the evaluation of some of the common hypotheses. If time and technology permits we will even play an online game.
Julien Gagneur - Modelling the regulatory code: From basic biology to clinical research
Technical University of Munich, Germany
My lab is interested in understanding how gene expression is encoded in genomes, and how to leverage this knowledge for medical application. To this end, we employ statistical modeling of ‘omics data and work in close collaboration with experimentalists. I will provide an overview of recent studies on RNA metabolism and protein expression control and on deep learning based models of cis-regulatory elements. I will also report on methodologies for using RNA-sequencing as a powerful companion tool to genome sequencing for pinpointing causes of rare genetic disorders.
Aurelien Tellier -Inference of past demography and life history traits from whole genome genetic and epigenetic data
Technical University of Munich, Germany
Several methods based on the Sequential Markovian coalescence (SMC) have been developed to use full genome sequence data to uncover population demographic history, which is of interest in its own right and is a key requirement to generate a null model for selection tests. While these methods can be applied in principle to all possible species, they have two main limitations: 1) the underlying assumptions are sexual reproduction at each generation and no overlap of generations, and 2) the inference accuracy depends on the ratio of recombination to mutation. However, in many plants, invertebrates, fungi and other taxa, these assumptions are often violated due to different ecological and life history traits, such as self-fertilization, long term dormant structures (seed or egg-banking) or large variance in offspring production. In this presentation I will first describe a novel SMC-based method which we developed to infer 1) the rates of seed/egg-bank and of self-fertilization, and 2) the populations' past demographic history. Using simulated data sets, we demonstrate the accuracy of our method for a wide range of demographic scenarios and for sequence lengths from one to 30 Mb using four sampled genomes. As a test, we apply our method to a Swedish and a German population of Arabidopsis thaliana demonstrating a selfing rate of ca. 0:87 and the absence of any detectable seed-bank. In contrast, we show that the water flea Daphnia pulex exhibits a long lived egg-bank of three to 18 generations. Second, I will provide recommendations for the use of SMC-based methods for non-model organisms, highlighting the importance of the per site and the effective ratios of recombination over mutation. Third, I will show some preliminary results on the effect and estimation of a violation of the Wright-Fisher model assumption, namely the large variance in offspring production which is common to fish, invertebrates and fungal species. Finally, if time permits, I will show some preliminary results on the use of methylation patterns to enhance the power of inference under an SMC model using both genetic and epigenetic markers.