2. Behavioral Biology TALKS - Deutsche Zoologische Gesellschaft

In an interdisciplinary approach, bringing together evolutionary ecologists and
sedimentologists, we are reconstructing population patterns and dynamics in the D.
longispina - galeata - cucullata complex south of the Alps as well as in D. pulicaria in
Lower Lake Constance. We also aim to identify patterns of pollution and
eutrophication across the Alps on the basis of lake sediments, in order to identify
factors that drive evolutionary change and invasion patterns in these groups.
S�13 Nicole Henning R513 / 16:45
The evolutionary adaptation potential of Daphnia galeata in time and space
Authors: Nicole Henning 1 , Mathilde Cordellier 1 , Bruno Streit 1 , Klaus Schwenk 1
Affiliation: 1 Biodiversity and Climate Research Centre, Frankfurt/Main
In the framework of global change research we aimed at estimating the impact of
elevated water temperatures on an aquatic keystone species, the freshwater
zooplankter Daphnia galeata. We performed two main experiments to measure
variation in life-history traits under different temperatures and to assess the
evolutionary adaptive potential of daphnids. For both experimental approaches we
sampled dormant egg banks of Daphnia galeata populations to obtain a
representative sample of natural genetic diversity. In addition to superficial sediment
layers, sampled along a latitudinal gradient across Europe, we used layers from
different depths in a ‚resurrection ecology‘ approach to study responses to variation
in water temperatures. We performed common-garden experiments after hatching
and establishment of clonal lineages in the laboratory. In flow-through-systems D.
galeata individuals from different time periods and latitudes were exposed to various
temperature regimes. To quantify the evolutionary potential of the resident natural
populations we compared their response to changes in temperature by measuring
several life history traits. In all experiments elevated water temperatures were shown
to result in a reduced body size, a higher reproduction rate, an increased somatic
growth rate and accordingly an earlier age at maturity. In addition to observed
phenotypic plasticity, significant temperature-age-interactions and temperatureorigin-interactions
indicate thermal micro-evolution within last decades. We discuss
these genetic adjustments regarding the consequences of global warming on the fate
of Daphnia populations and the freshwater ecosystems they inhabit.
S�14 Johanna Griebel R513 / 17:00
Can a hybrid outcompete its parental species? - a competition experiment with a
“super clone” (Daphnia galeata × longispina hybrid)
Authors: Johanna Griebel 1 , Monika Poxleitner 1 , Sabine Gießler 1 , Justyna Wolinska 1
Affiliation: 1 Ludwig-Maximilians-Universität München
Interspecific hybridization is an important force in evolutionary processes, leading to
new genotypes and adaptations to new environments. In general, hybrids show
lower fitness than their parental species. However, during the last years it has been
found that the Daphnia longispina community inhabiting a small quarry lake in
Munich (Feldmochinger See) has become dominated by a single hybrid clone. This
‘super clone’ outcompeted the entire population of hybrids and against all
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