IZS-Kolloquium

21.04.23

 Dr. 

Shannon Currie

IZS AG Funktionelle Ökologie

 The costs and limitations of call intensities in echolocating bats

The ability to vocalize is of pivotal importance in the animal kingdom, but vocalization often comes with energetic costs, particularly when produced at high intensity. Among animals that vocalize loudly, the limit to their call intensity has rarely been addressed. In bats, which often call at high intensities, the metabolic costs of echolocation in flight are thought to be negligible enabling the evolution of high intensity echolocation. We examined whether the limitations to call intensity are defined by the trade-off between metabolic costs and maximum range of the sound. To do this, we measured the metabolic and acoustic costs of extremely loud vocalizations in echolocating Pipistrellus nathusii during controlled flight in a wind tunnel. By comparing metabolic rates of flying bats calling at varying intensities, we show that this is only true for low call intensities. Our results demonstrate that above 130 dB SPL (re. 10cm), the costs of sound production become exorbitantly expensive for small bats, placing a limitation on the intensity at which they can call. We propose that this may extend to other animals vocalizing in air, where a balance is struck between maximizing the range of transmission and keeping it energetically affordable to vocalize.

Prof. Dr.

Barbara Taborsky 

Universität Bern

The evolution of plastic social phenotypes

In cooperatively breeding cichlids developmental plasticity gives rise to divergent life history trajectories resulting in distinct social phenotypes characterized by their social competence and helping propensity. Social trajectories are determined by social and ecological early-life experiences. I discuss mechanistic underpinnings of these social phenotypes and their possible role in social evolution.

12.05.23

 Dr. Shab Mohammadi

IZS AG Molekulare Evolutionsbiologie

 Snake time machine: investigating constraints on evolution through ancestral protein resurrection

The repeated evolution of resistance to widespread toxins collectively known as cardiotonic steroids represents one of the clearest examples of natural selection. Numerous plants and animals across the globe are chemically defended by these toxins, which target the vital transmembrane protein Na+K+-ATPase (NKA). In response, many herbivores and predators evolved resistance through target-site insensitivity of NKA. This adaptation has been repeatedly achieved by one or two amino acid substitutions at the same sites in the protein and has demonstrated remarkable patterns of convergence, divergence, and parallelism in evolution. Such patterns are expected to be shaped by the degree of pleiotropy (i.e. the effect of a mutation on multiple traits) and intramolecular epistasis (i.e. nonadditive interactions between mutant sites in the same protein). I will discuss the extent to which these constraining factors have shaped this adaptation in a group of animals that have repeatedly gained it: snakes. 

 Dr. Joanna Malukiewicz 

IZS AG Evolutionäre Immungenetik

 An evolutionary genomics perspective on marmosets, the worlds smallest monkeys, with a focus on Callithrix

Callithrix marmosets are unique among primates, as being among the world's smallest monkeys (approximately 100g-500g) and by "parasitizing" trees to nutritionally exploit tree gums, a relatively low-value nutritional resource. Several marmoset species are highly endangered, but  these monkeys are overlooked genomically. Thus, I will give a general overview of marmosets and discuss the evolution of marmoset biological traits from a newly emerging genomics point of view.

02.06.23

 Prof. Dr. Andreas Schmidt-Rhaesa

LIB

 Love for strange creatures: Notes on priapulids (Priapulida) and other weirdos

My research interests focus on the morphology and phylogeny of animal taxa, which are still much understudied. In my talk I will focus on priapulid worms (Priapulida). These comprise only 21 extant species, but are nevertheless diverse and important in an evolutionary context. While presenting the approaches of my working group I will present several aspects of the morphology and biology of priapulids, from being large predators in mud in temperate regions to being small components of tropical sediments. In very brief form I will give an overview of other aspects and other taxa of my research.

09.06.23

Dr. Anja Günther

MPI Evolutionbiologie, Plön

 Early steps of adapting to environmental change

Environmental conditions change constantly either by anthropogenic perturbation or naturally across space and time. The most immediate adaptive mechanism allowing populations to face these changes occurs at the individual level through phenotypic plasticity. For many animals a change in behaviour is often the first response to changing conditions. Behavioural flexibility can potentially improve an organism’s chances to survive and reproduce. Currently, we lack an understanding on the time-scale such behavioural adjustments need in natural systems, how they actually affect reproduction and survival and what the underlying mechanisms driving such fast adjustment processes are. We use wild-derived house mice (Mus musculus domesticus) living under semi-natural conditions to understand how differences in food quality shape phenotypic differences in life history, morphology, physiology and behavior across several generations. We follow individual life histories (N > 3500) of all animals born in the population and we test a random subset of individuals for various behavioural traits such as risk-taking, stress-coping or cognitive abilities in every generation. We study the underlying physiological and molecular mechanisms driving adjustment of life history and behaviour as well as consequences for reproduction and survival when the environment remains constant or changes unexpectedly. Ultimately, we aim to achieve a comprehensive understanding on how animals adjust to changing environments and specifically want to understand the role of behavioural variation for such adjustments.

 Dr. James Turner

UWS, Glasgow

From hibernation to heatwaves: mammal ecophysiology in challenging environments

Environmental stressors impact the success and survival of wildlife in myriad ways. They range from day-to-day pressures such as food availability or predator presence, to extraordinary events like bushfires or heatwaves. Heatwaves are predicted to increase in intensity, frequency and duration with ongoing global warming. Although relatively brief, they can bear long-lasting ecological consequences by having both sub-lethal (e.g., reduced body condition) and lethal effects. As such, heatwaves will increasingly pose a globally significant problem for animal species. To better understand the direct effects of high ambient temperature on wildlife, we need empirical studies examining species' physiological responses and how these fit in with aspects of their behaviour and ecology. It appears that strategies that can save water, but keep an animal cool, are vital for avoiding hyperthermia and dehydration and surviving heatwaves when there is limited capacity for escaping heat via behavioural means. To aid conservation efforts, improving our understanding of animal responses to environmental heat is crucial.