Did you know that an amazing biodiversity exists just beneath your feet?

Yes! Hundreds of invertebrate species can be found in 1 m2 of forest soil and one gram of soil contains hundreds of fungi and bacteria species. This is why soil has been termed „the poor man's tropical rainforest“. But why is soil so diverse? This is still not well understood, neither the full extent of the complexity of interactions, nor the functions of species in communities.

My research focuses on oribatid mites (Chelicerata, Acari) and springtails (Hexapoda, Collembola), the most common and abundant organisms of mesofauna in soil. Mesofauna describes all animals in soil with a body-size ranging from 0.1 – 2 mm. Though being very little, oribatid mites and springtails contribute to very important processes in soil, including nutrient cycling by processing organic matter that enters the soil system from above the ground and releasing nutrients which are then consumed again by plants.

Did you know that asexual reproduction is quite common in soil? One type of parthenogenesis, the production of diploid eggs by unfertilized females, is particularly common in oribatid mites. About 10% of all oribatid mite species reproduce without males, for hundreds of millions of years. And similar patterns have been found in Collembola.

In my research, I combine ecological and evolutionary views. For this, I use molecular markers to reconstruct phylogenies and combine these with ecological traits of species. A robust phylogeny is of major importance to understand in which context ecological traits evolved. Ecological traits are important to understand the function of species in the soil community. Understanding the function of species and communities is important to follow the complex processes in soil and eventually grasp the enigma of soil animal diversity.

Further, I investigate genetic diversity of soil organisms at small and large geographic scales. The genetic structure of populations, the genetic connectivity of regions, and the divergence times of lineages provide insight into historical, geological and ecological factors that shaped soil-living communities.

Eventually, the striking frequency of parthenogenesis in soil is an evolutionary mystery. Theoretically, species that reproduce without sex should go extinct after some time, due to mutational meltdown or too little adaptive potential. Using phylogenies, phylogeography and genomic and transcriptomic data, my working group investigates the origin, phylogenetic distribution and genetic consequences of long-term parthenogenesis.

Interested?

Write me an email for more information.



Publication list

Klein A, Eisenhauer N, Schaefer I. Invasive lumbricid earthworms in North America – different life histories but common dispersal? to be submitted

Zhang B, Chen T-W, Mateos E, Schaefer I, Scheu S. DNA-based approaches open up cryptic diversity in the European Lepidocyrtus lanuginosus species group (Collembola: Entomobryidae). submitted

2018
Zhang B, Chen T-W, Mateos E, Scheu S, Schaefer I (2018). Cryptic species in Lepidocyrtus lanuginosus (Collembola: Entomobryidae) are sorted by habitat type. Pedobiologia 68, 12-19

Gong X, Chen T-W, Zieger SL, Bluhm C, Heidemann K, Schaefer I, Maraun M, Liu M, Scheu S (2018). Phylogenetic and trophic determinants of gut microbiota in soil oribatid mites. Soil Biology and Biochemistry 123, 155-164

2017
Chen T-W, Sandmann P, Schaefer I, Scheu S (2017). Neutral lipid fatty acid composition as trait and constraint in Collembola evolution. Ecology and Evolution 7, 9624-9638

Klein A, Cameron E, Heimburger B, Eisenhauer N, Scheu S, Schaefer I (2017). Changes in the genetic structure of an invasive earthworm species (Lumbricus terrestris, Lumbricidae) along an urban-rural gradient in North America. Applied Soil Ecology 12, 265-272

Pachl P, Lindl A, Krause A, Scheu S, Schaefer I, Maraun M (2017). The tropics as an ancient cradle of oribatid mite diversity. Acarologia 57, 309-322

von Saltzwedel H, Scheu S, Schaefer I (2017). Genetic diversity and distribution of Parisotoma notabilis (Collembola) in Europe: cryptic diversity, split of lineages and colonization patterns. PLoS ONE 12: e0170909

2016
Krause A, Pachl P, Schulz G, Lehmitz R, Seniczak A, Schaefer I, Scheu S, Maraun M (2016). Convergent evolution of aquatic life by sexual and oribatid mites. Experimental and Applied Acarology 70: 439-453

von Saltzwedel H, Scheu S, Schaefer I (2016). Founder events and pre-glacial divergences shape the genetic structure of European Collembola species. BMC Evolutionary Biology 16: 148

Bast J, Schaefer I, Schwander T, Maraun M, Scheu S, Kraaijeveld K (2016). No accumulation of transposable elements in asexual arthropods. Molecular Biology and Evolution, doi: 10.1093/molbev/msv261

2015
Kreipe V, Corral-Hernández E, Scheu S, Schaefer I, Maraun M (2015). Phylogeny and species delineation in European species of the genus Steganacarus (Acari, Oribatida) using mitochondrial and nuclear markers. Experimental and Applied Acarology 66, 173-186.

2014 and older
von Saltzwedel H, Maraun M, Scheu S, Schaefer I (2014). Evidence for Frozen-Niche Variation in a cosmopolitan parthenogenetic soil mite species (Acari, Oribatida). PloSOne 9, e113268.

Rosenberger M, Maraun M, Scheu S, Schaefer I (2013). Pre- and post-glacial diversifications shape genetic complexity of a soil-living micro-arthropod. Pedobiologia 56, 79-87
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Henke C, Nickel H, Scheu S, Schaefer I (2013). Evidence for Wolbachia in leafhoppers of the genus Eupteryx with intersexual morphotypes. Bulletin of Insectology 66, 109-118.

Pachl P, Domes K, Schulz G, Norton RA, Scheu S, Schaefer I, Maraun M (2012). Convergent evolution of defense mechanisms in oribatid mites (Acari, Oribatida) shows no ”ghost of predation past”. Molecular Phylogenetics and Evolution 65, 412-420.

Schaefer I, Norton RA, Scheu S, Maraun M 2010. Arthropod colonization of land – linking molecules and fossils in oribatid mites (Acari, Oribatida). Molecular Phylogenetics and Evolution 57, 113-121.

Schaefer I, Domes K, Heethoff M, Schön I, Norton RA, Scheu S, Maraun M 2006. No evidence for the ‚Meselson effect’ in parthenogenetic oribatid mites (Oribatida, Acari). Journal of Evolutionary Biology 19, 184-193.