Genomic zoo

Model species

Crows (Corvus)

Speciation. We use the replicated hybrid zone between all-black carrion crows and grey-coated hooded crows to investigate the genetic basis of reproductive isolation at an early stage of population divergence. Beyond this species complex we address general questions of molecular evolution (e.g. distribution of fitness effects, dosage compensation, TE evolution) using comparative analyses across the genus Corvus - consisting of crows, ravens and jackdaws. The hybrid zone setup is further suitable to more generally address gentic control of phenotypic variation including epigenetic variation.

Cuckoos (Cuculus)

Host-parasite interactions. Common cuckoos are brood parasites that lay mimetic eggs in a variety of host nests, leaving parental care entirely to the hosts. Since raising cuckoo chicks is costly, hosts strive to become experts at detecting eggs that differ from their own, while selective pressures are simultaneously on cuckoos to lay eggs that match their hosts. We study the genetic basis of this coevolutionary arms race from the cuckoo perspective.

Estrilid finches (Taeniopygia, Lonchura)

Inversions. Inversions alter the recombination landscape and can lock co-adapted gene complexes together. We use zebra finch pedigrees and single sperm sequencing to understand the impact of inversions on recombination. We further analyse data from estrilid populations in the wild to assess how naturally occurring inversions maybe affected by selection.

Fireflies (Lamphrohiza, Lampyris)

Evolutionary genomics. Fireflies are fascinating insects not only because of their production of bioluminescence, but also because of their ability to adapt to different environments and their strong sexual dimorphism. We use genomic tools to understand their demographic past, adaptability to colonize new habitats and the genetics underlying their extreme sexual dimorphism.

Frogs (Pelophylax)

Hybridogenesis. European water frogs display the interesting phenomenon of hybridogenesis. Upon the mating of two divergent sister species, the genome of one of the parental species is discarded during meiosis. Which of parents depends is in part population specific. In contrast to other hemiclonal systems hemiclonal transmission is not limited to one sex. This curious system of reproduction allows insights into mechanisms of hybridization, reproductive isolation and sex chromosome evolution.

Killer whales (Orcinus)

Population genetics. Killer whales resemble humans in many respects. They are large cosmopolitan mammals that diversified about ~250,000 years ago into several lineages with evidence for transmission of cultural hunting practices. Using genomic data we try to shed light on their complex demographic history, ecological adaptation and other aspects of an interesting marine biology.

Pinnipeds (Pinnipedia, Zalophus, Arctocephalus)

Speciation and conservation. In order to study the process and outcomes of speciation we can learn a lot from “natural experiments”. The Galápagos archipelago is often described as a natural laboratory of evolution with species evolving in situ. We focus on the Galápagos sea lion and use genetic sequences to try and understand their colonization history and endemic ecotype divergence. Beyond the Galápagos we use this animal group (sea lions, seals, walruses) to study the impact of life history variation on genetic diversity.

Swallows (Hirundo)

Migratory divide. Migratory divides are special hybrid zones with divergence in a behavioral phenotype. European barn swallows overwinter in different locations in Afrika entailing differences in migration route and distance. Within a migratory divide in northern Germany migratory behavior is highly variable. Using a combination of stable isotope data, light loggers and genomic tools we strive to investigate the genetic basis of this migratory polymorphism and its relevance for population divergence.

Epigenetic variation.

Tits (Parus major, Cyanistes caerulus, Poecile montanus)

Epigenetic variation. The relevance of epigenetic variation for animal evolution remains largely unclear. We draw from large pedigree datasets in great tits and blue tits to quantify the heritability of epigenetic variation (5mC methylation) and assess the relative impact of cis-genetic variation and environmental trans-effects.

Speciation. Prezygotic isolation has long been discussed as a rapid driver of reproductive isolation. The willow tit has evolved local song types that intermingle in hybrid zone (one is close to the Institue in Munich). We retrace the evolutioanry history of these song types, investigate whether this trait is inherited or learned and assess the consequences for reproductive isolation.

Yeast (Schizosaccharomyces)

Adaptive divergence. Adaptive divergence is the key evolutionary process generating biodiversity by means of natural selection. Yet, the conditions under which it can arise in the presence of gene flow remain contentious. We use experimental evolution in fission yeast to study the processes underlying adaptive divergence under conditions of gene flow. In a long-term replicated experiment, we apply disruptive viability selection and manipulated the level of migration between environments.

Miscellanea

including involvement in studies of Drosophila, mouse, newts