I am a senior postdoctoral researcher at the University of Bern and Eawag (Group Seehausen), both in Switzerland, studying organismal diversification, especially in the context of cichlid fish adaptive radiation. I'm currently using a paleogenetic approach to investigate Lake Victoria's haplochromine cichlids, funded through an SNSF Sinergia grant.
In previous work, I explored patterns of ecological specialisation and genomic divergence of Timema stick insects together with Patrik Nosil at the University of Sheffield, UK, and speciation and ecomorphological evolution of cichlid fishes in the groups of Axel Meyer (University of Konstanz, Germany) and Walter Salzburger (University of Basel, Switzerland).
NEWS & EVENTS
In this new pre-print (manuscript in review at Molecular Ecology), we show for the first time that fish fossils from tropical lake sediments yield endogenous ancient DNA. Despite generally low endogenous content and high sample drop-out, high-throughput sequencing and in some cases sequence capture allowed for taxonomic assignment to family or tribe level and phylogenetic placement of individuals. Even skeletal remains weighing less than 1 mg and up to 2700 years of age could be phylogenetically placed. Success rates and aDNA preservation differed between the investigated lakes Chala, Kivu and Victoria, possibly caused by differences in water oxygenation at deposition. Our study demonstrates that sediments of tropical lakes preserve genetic information on rapidly diversifying taxa over time scales of millennia.
New paper Through the diligent work of Yunuén and co-workers, we can present the first continuous sedimentary charcoal records from Lake Victoria and a cutting-edge age model to boost. Charcoal data suggest that fire activity varied substantially during the past 17,000 years, and our new pollen records reveal the long-term vegetation dynamics. We infer that before human impact increased during the Iron Age (ca. 2400 yr BP), biomass burning was linked to climate and vegetation reorganizations, such as warming, drying, and the expansion of rainforests and savannas.
New paper In Polar Biology, my co-authors and I report the mitochondrial genome sequence of the antarctic ice fish Channichthys rugosus. We pieced it together from extremely short DNA fragments from an almost 50 year old, formalin-fixed museum specimen. This was made possible through application of ancient DNA methods, such as single-stranded DNA library preparation.
INTECOL 2022 At the INTECOL conference 2022 in Geneva, Nare Ngoepe, Ole Seehausen and I organised a session on "Palaeolimnology placed in an evolutionary context" with great contributions on a variety of systems.
Far4ViBE, SIAL8 and ICDP workshop on Lake Victoria drilling Busy times during field work and three events back-to-back in Tanzania. Was great to catch up with many colleagues and make new connections – and say hi to Lake Tanganyika's fabulous cichlids once again.
ISBA9 conference The International Symposium of Biomolecular Archaeology is on again, and this time I'm participating. Great to see what fantastic findings can be created with paleoproteomics and ancient DNA from tiny amounts of diverse substrates.
Practical in Aquatic Ecology & Evolution During this year's two weeks long intensive practical we will investigate fish adaptive radiations using geometric morphometrics and phylogenetic comparative methods.
New paper: Large-scale mutation in the evolution of a gene complex for cryptic coloration. Published in Science
New paper: Adaptive zones shape the magnitude of premating reproductive isolation in Timema stick insects. Published in Philosophical Transactions of the Royal Society B
Practical in Aquatic Ecology & Evolution During this year's four weeks long intensive practical we will investigate the fish community composition in Lake Constance through time using sediment cores.