Max Planck Institute for Evolutionary Biology

Plon, Germany

Max Planck Institute for Evolutionary Biology

Plon, Germany

The Max Planck Institute for Evolutionary Biology is a German institute for evolutionary biology. It is located in Plön, Schleswig-Holstein, Germany. Wikipedia.

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News Article | May 4, 2017

A common parasite that lives in fish eyeballs seems to be a driver behind the fish’s behaviour, pulling the strings from inside its eyes. When the parasite is young, it helps its host stay safe from predators. But once the parasite matures, it does everything it can to get that fish eaten by a bird and so continue its life cycle. The eye fluke Diplostomum pseudospathaceum has a life cycle that takes place in three different types of animal. First, parasites mate in a bird’s digestive tract, shedding their eggs in its faeces. The eggs hatch in the water into larvae that seek out freshwater snails to infect. They grow and multiply inside the snails before being released into the water, ready to track down their next host, fish. The parasites then penetrate the skin of fish, and travel to the lens of the eye to hide out and grow. The fish then get eaten by a bird – and the cycle starts again. Many parasites can change an animal’s behaviour to fit their own needs. Mice infected with the parasite Toxoplasma gondii, for example, lose their fear of cats – the animal the parasite needs to reproduce inside. In a 2015 study, Mikhail Gopko at the Severtsov Institute of Ecology and Evolution in Moscow and his colleagues showed that fish infected with immature fluke larvae swam less actively than usual – making themselves less visible to predators – and were harder to catch with a net than uninfected controls. Now, the same team has tested rainbow trout harbouring mature eye flukes – parasites ready to reproduce inside their bird hosts. The team found that these trout swam more actively than uninfected controls and stayed closer to the water’s surface. Both traits should make fish more conspicuous to birds. When the researchers simulated a bird attack by making a shadow swoop over the tank, the fish froze – but infected fish resumed swimming sooner than uninfected ones. Gopko says both studies show that how eye flukes manipulate their host’s behaviour depends on their age. Immature parasites “are too young and innocent to infect a next host”, he says, so their goal is to protect the fish they are living in. Mature parasites, however, are ready to reproduce – and to do so they need to get inside a bird’s gut. Some earlier studies suggested fluke-infected fish act differently because of impaired vision. But the authors say vision problems wouldn’t explain changes to unfreezing time, or the opposite effects of mature and immature parasites. The researchers also tested how long it took fish to unfreeze after attack when they were infected with both mature and immature parasites at once. Their behaviour matched that of fish carrying only mature parasites. When the parasites’ goals conflict, Gopko says, “mature guys are clear winners”. This fits a pattern of young parasites decreasing their host’s likelihood of being preyed on, while older parasites increase it, says Nina Hafer, a parasitologist at the Max Planck Institute for Evolutionary Biology in Plön, Germany. Few studies have pitted mature and immature parasites against each other in one host, she says. “It contributes to showing how many traits and species can be affected by host manipulation, which should make it an important factor in how parasites alter the ecological interactions of their hosts,” she says. Read more: The cat made me do it: Is your pet messing with your mind?

Hiltunen T.,University of Helsinki | Becks L.,Max Planck Institute for Evolutionary Biology
Nature Communications | Year: 2014

Rapid evolution in ecologically relevant traits has recently been recognized to significantly alter the interaction between consumers and their resources, a key interaction in all ecological communities. While these eco-evolutionary dynamics have been shown to occur when prey populations are evolving, little is known about the role of predator evolution and co-evolution between predator and prey in this context. Here, we investigate the role of consumer co-evolution for eco-evolutionary feedback in bacteria-ciliate microcosm experiments by manipulating the initial trait variation in the predator populations. With co-evolved predators, prey evolve anti-predatory defences faster, trait values are more variable, and predator and prey population sizes are larger at the end of the experiment compared with the non-co-evolved predators. Most importantly, differences in predator traits results in a shift from evolution driving ecology, to ecology driving evolution. Thus we demonstrate that predator co-evolution has important effects on eco-evolutionary dynamics. © 2014 Macmillan Publishers Limited. All rights reserved.

Haubold B.,Max Planck Institute for Evolutionary Biology
Briefings in Bioinformatics | Year: 2014

Phylogenetics and population genetics are central disciplines in evolutionary biology. Both are based on comparative data, today usually DNA sequences. These have become so plentiful that alignment-free sequence comparison is of growing importance in the race between scientists and sequencing machines. In phylogenetics, efficient distance computation is the major contribution of alignment-free methods. A distance measure should reflect the number of substitutions per site, which underlies classical alignment-based phylogeny reconstruction. Alignment-free distance measures are either based on word counts or on match lengths, and I apply examples of both approaches to simulated and real data to assess their accuracy and efficiency. While phylogeny reconstruction is based on the number of substitutions, in population genetics, the distribution of mutations along a sequence is also considered. This distribution can be explored by match lengths, thus opening the prospect of alignment-free population genomics. © The Author 2013. Published by Oxford University Press.

Werner B.,Max Planck Institute for Evolutionary Biology
Journal of the Royal Society, Interface / the Royal Society | Year: 2013

Cancers are rarely caused by single mutations, but often develop as a result of the combined effects of multiple mutations. For most cells, the number of possible cell divisions is limited because of various biological constraints, such as progressive telomere shortening, cell senescence cascades or a hierarchically organized tissue structure. Thus, the risk of accumulating cells carrying multiple mutations is low. Nonetheless, many diseases are based on the accumulation of such multiple mutations. We model a general, hierarchically organized tissue by a multi-compartment approach, allowing any number of mutations within a cell. We derive closed solutions for the deterministic clonal dynamics and the reproductive capacity of single clones. Our results hold for the average dynamics in a hierarchical tissue characterized by an arbitrary combination of proliferation parameters. We show that hierarchically organized tissues strongly suppress cells carrying multiple mutations and derive closed solutions for the expected size and diversity of clonal populations founded by a single mutant within the hierarchy. We discuss the example of childhood acute lymphoblastic leukaemia in detail and find good agreement between our predicted results and recently observed clonal diversities in patients. This result can contribute to the explanation of very diverse mutation profiles observed by whole genome sequencing of many different cancers.

Milinski M.,Max Planck Institute for Evolutionary Biology
Behavioral Ecology | Year: 2014

The design of brains, sense organs, or immune systems is an impressive product of natural selection, far ahead of human engineering capability. But what if behavior is less well adapted? A bird's perfect eye is useless if it fails to avoid a stalking cat. If we fail in choosing a partner with complementary immunogenes, our ability to detect major histocompatibility complex-dependent body odors is worthless. Besides being able to detect all available prey items, the diet that maximizes net energy gain must be chosen. Individuals that are selected naturally will be those best able to avoid predators, choose mates, select food, and so on. Those with less perfect behavior produce fewer offspring, and their genotypes will disappear. Ecology is the stage on which the fittest have behaved most successfully. Thus, their strategies prevail today. Behavioral ecology is about the optimal design of behavior. © 2014 The Author.

Turner L.M.,Max Planck Institute for Evolutionary Biology | Harr B.,Max Planck Institute for Evolutionary Biology
eLife | Year: 2014

Mapping hybrid defects in contact zones between incipient species can identify genomic regions contributing to reproductive isolation and reveal genetic mechanisms of speciation. The house mouse features a rare combination of sophisticated genetic tools and natural hybrid zones between subspecies. Male hybrids often show reduced fertility, a common reproductive barrier between incipient species. Laboratory crosses have identified sterility loci, but each encompasses hundreds of genes. We map genetic determinants of testis weight and testis gene expression using offspring of mice captured in a hybrid zone between M. musculus musculus and M. m. domesticus. Many generations of admixture enables high-resolution mapping of loci contributing to these sterility-related phenotypes. We identify complex interactions among sterility loci, suggesting multiple, non-independent genetic incompatibilities contribute to barriers to gene flow in the hybrid zone.

Milinski M.,Max Planck Institute for Evolutionary Biology
Philosophical Transactions of the Royal Society B: Biological Sciences | Year: 2016

Decision rules of reciprocity include ‘I help those who helped me’ (direct reci- procity) and ‘I help those who have helped others’ (indirect reciprocity), i.e. I help those who have a reputation to care for others. A person’s reputa tion is a score that members of a social group update whenever they see the person interacting or hear at best multiple gossip about the person’s social interactions. Reputation is the current standing the person has gained from previous investments or refusal of investments in helping others. Is he a good guy, can I trust him or should I better avoid him as a social partner? A good reputation pays off by attracting help from others, even from strangers or members from another group, if the recipient’s reputation is known. Any costly investment in others, i.e. direct help, donations to charity, investment in averting climate change, etc. increases a person’s reputation. I shall argue and illustrate with examples that a person’s known reputation functions like money that can be used whenever the person needs help. Whenever possible I will present tests of predictions of evolutionary theory, i.e. fitness maximizing strategies, mostly by economic experiments with humans. © 2016 The Author(s) Published by the Royal Society. All rights reserved.

Milinski M.,Max Planck Institute for Evolutionary Biology
Neuroscience and Biobehavioral Reviews | Year: 2014

Female preference for secondary sexual male ornaments that are handicapping survival has been an evolutionary puzzle since Darwin. The Hamilton-Zuk hypothesis assumes that costly ornaments can be produced only by those males that carry the genes for resistance against the current infectious disease. I review studies in fishes that indeed bright colors can only be displayed by males in good health and females prefer healthy males by choosing the brighter ones. On the other hand, female vertebrates from fish to humans smell out partners that provide the complementary genes of the major histocompatibility complex (MHC) to help them producing offspring with the optimal number of different MHC alleles. In sticklebacks females have a two-step choice. Using smell they approach a male that offers the optimally complementary number of MHC alleles. When they can see the male, they accept it only when it is bright and thus offers in its complementary set of alleles the specific MHC allele providing resistance against the current disease as revealed by the male's sexual ornamentation. © 2014 Elsevier Ltd.

Reeves R.G.,Max Planck Institute for Evolutionary Biology
PloS one | Year: 2014

The idea of introducing genetic modifications into wild populations of insects to stop them from spreading diseases is more than 40 years old. Synthetic disease refractory genes have been successfully generated for mosquito vectors of dengue fever and human malaria. Equally important is the development of population transformation systems to drive and maintain disease refractory genes at high frequency in populations. We demonstrate an underdominant population transformation system in Drosophila melanogaster that has the property of being both spatially self-limiting and reversible to the original genetic state. Both population transformation and its reversal can be largely achieved within as few as 5 generations. The described genetic construct {Ud} is composed of two genes; (1) a UAS-RpL14.dsRNA targeting RNAi to a haploinsufficient gene RpL14 and (2) an RNAi insensitive RpL14 rescue. In this proof-of-principle system the UAS-RpL14.dsRNA knock-down gene is placed under the control of an Actin5c-GAL4 driver located on a different chromosome to the {Ud} insert. This configuration would not be effective in wild populations without incorporating the Actin5c-GAL4 driver as part of the {Ud} construct (or replacing the UAS promoter with an appropriate direct promoter). It is however anticipated that the approach that underlies this underdominant system could potentially be applied to a number of species.

Neme R.,Max Planck Institute for Evolutionary Biology | Tautz D.,Max Planck Institute for Evolutionary Biology
BMC Genomics | Year: 2013

Background: New gene emergence is so far assumed to be mostly driven by duplication and divergence of existing genes. The possibility that entirely new genes could emerge out of the non-coding genomic background was long thought to be almost negligible. With the increasing availability of fully sequenced genomes across broad scales of phylogeny, it has become possible to systematically study the origin of new genes over time and thus revisit this question. Results: We have used phylostratigraphy to assess trends of gene evolution across successive phylogenetic phases, using mostly the well-annotated mouse genome as a reference. We find several significant general trends and confirm them for three other vertebrate genomes (humans, zebrafish and stickleback). Younger genes are shorter, both with respect to gene length, as well as to open reading frame length. They contain also fewer exons and have fewer recognizable domains. Average exon length, on the other hand, does not change much over time. Only the most recently evolved genes have longer exons and they are often associated with active promotor regions, i.e. are part of bidirectional promotors. We have also revisited the possibility that de novo evolution of genes could occur even within existing genes, by making use of an alternative reading frame (overprinting). We find several cases among the annotated Ensembl ORFs, where the new reading frame has emerged at a higher phylostratigraphic level than the original one. We discuss some of these overprinted genes, which include also the Hoxa9 gene where an alternative reading frame covering the homeobox has emerged within the lineage leading to rodents and primates (Euarchontoglires). Conclusions: We suggest that the overall trends of gene emergence are more compatible with a de novo evolution model for orphan genes than a general duplication-divergence model. Hence de novo evolution of genes appears to have occurred continuously throughout evolutionary time and should therefore be considered as a general mechanism for the emergence of new gene functions. © 2013 Neme and Tautz; licensee BioMed Central Ltd.

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