Although pinnipeds were hunted by humans since the stone age, commercial seal harvesting during the last three centuries brought many species to the edge of extinction. Some species managed to largely recover their population sizes (such as the northern elephant seal or the antarctic fur seal) and others have never been seen again. The probably most extreme example is the Northern Elephant Seal, where just a handful of individuals survived the big hunt for their blubber.
While population bottlenecks can cause a considerable loss of genetic variation, the question remains whether the fitness of post-bottleneck generations suffers too. In addition, seals are often highly polygynous, whereby males guard and mate with large harems of females, which potentially slows down the recovery of genetic variation. It becomes clear, that avoiding inbreeding and maximising genetic variation is of fundamental importance to many seal species.
Broadly speaking, I am studying both the causes and some of the more surprising consequences of genetic variation in pinnipeds. Recently, my colleagues and I used a comparative genetic approach to infer the recent demographic histories of 30 pinniped species and how these shape variation in contemporary genetic diversity (see here). Previously, I worked at the interface of chemical ecology and population genetics by investigating the genetic basis of chemical communication in fur seals. My current work however focuses mostly on the Northern elephant seal, a species which is extraordinary in many ways. After surviving its near extinction due to overhunting just a century ago, the species still fascinates with its extreme sexual dimorphism and highly polymorphic mating system, with few males guarding harems of many dozens of females every breeding season. At the moment, I am investigating the genomic consequences of the past bottleneck using RAD sequencing and hopefully a new genome assembly, the species genetic resistance towards parasite infections and the development of its gut microbiota during the weaning period.
An important aspect of my work is R programming. Biology is evolving rapidly and changing towards a more open and data-intense science. The increasing complexity of both problems and methods in fields such as ecology and population genetics also requires a change in terms of transparency and reproducibility of analyses.
The R language provides the unique opportunity to easily document and publish code and develop packages for the scientific community, often simply as a byproduct of ongoing projects. At the moment I am one of the main authors of three scientific R packages on CRAN. (1) inbreedR provides a framework for the analysis of inbreeding and HFCs based on genetic marker data, such as SNPs and microsatellites. (2) Together with Holger Schielzeth and Shinichi Nakagawa I revised the rptR package, which provides methods for the estimation of raw variances, repeatabilities and marginal R2 within a mixed model framework. (3) The newest project together with Meinolf Ottensmann is GCalignR, a package to align data from gas-chromatography, which we developed to detect patterns in olfactory profiles of wild animal populations.
Outside of work, I try to keep a harmony between my mind and body. I’m coming from a background in competitive swimming and still try to do all kinds of sports, at the moment mostly running. Usually, I´m reading two or three books at a time (from which I rarely finish one to be honest) to keep an open mind about things apart from what I am doing on a daily basis. Besides that, I recently became a passionate touring cyclist and photographer with a special interest in wildlife and landscapes.
Supervisors and Collaborators
Joe Hoffman, Bielefeld University, Germany
Hazel Nichols, Liverpool John Moores University, UK
Kanchon Dasmahapatra, University of York, UK
Karina Acevedo-Whitehouse, Autonomous University of Queretaro
Holger Schielzeth, Dept. of Evolutionary Biology, Bielefeld University Germany
Mareike Esser, Dept. of Biomathematics and Theoretical Bioinformatics, Bielefeld University Germany
- 2012–2014: M.Sc. Behaviour: From neural mechanisms to evolution – Bielefeld University (focus: ecology and neuroscience)
- 2009–2012: B.Sc. Psychology – University of Koblenz-Landau
- Stoffel MA et al. Genomics reveals the demographic history of the Northern elephant seal. In prep.
- Stoffel MA et al. Early sex-specific differentiation, development and genetic basis of the gut microbiota in a highly polygynous marine mammal, the Northern elephant seal. In prep.
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- Eberhart-Phillips LJ, Küpper C*, Miller TEX, Cruz-López M, Maher KH, dos Remedios N, Stoffel MA, Hoffman JI*, Krüger O*, Székely T*. Adult sex ratio bias in snowy plovers is driven by sex-specific early survival: implications for mating systems and population growth, Proceedings of the National Academy of Sciences of the United States of America, doi:10.1073/pnas.1620043114.
- Stoffel, M.A., Nakagawa, S., Schielzeth, H. (2017). rptR: Repeatability estimation and variance decomposition by generalized linear mixed-effects models. Methods in Ecology and Evolution (2017). DOI: 10.1111/2041-210X.12797. Paper and link to the package
- Ottensmann, M.*, Stoffel, M. A.*, & Hoffman, J. I. (2017). GCalignR: An R package for aligning Gas-Chromatography data. bioRxiv, 110494. * Contributed equally. Here is the link to the package
- Stoffel, M.A., Esser, M., Kardos, M., Humble, E., Nichols, H.J., David, P. & Hoffman, J.I.. inbreedR: An R package for the analysis of inbreeding based on genetic markers. Methods in Ecology and Evolution (2016). Supplementary Information . Here is the link to the package. .
- Stoffel, M., Caspers, B.A., Forcada, J., Giannakara, A., Baier, M.C., Eberhart-Phillips, L.J., Müller, C. & Hoffman, J.I. (2015) Chemical fingerprints encode mother-offspring similarity, colony membership, relatedness and genetic quality in fur seals. Proceedings of the National Academy of Sciences of the United States of America., 112: E5005-E5012. Doi:10.1073/pnas.1506076112 Supplementary Information R code Journal cover Commentary article in PNAS and JEB
- Stoffel M, Reis D, Schwarz D & Schröder A (2013). Dimensions of coping in Fibromyalgia patients: Factor analysis and cross-validation of the Coping Strategies Questionnaire (CSQ-D).Rehabilitation Psychology.
- Stoffel, M., Caspers, B.A., Forcada, J., Giannakara, A., Baier, M.C., Eberhart-Phillips, L.J., Müller, C. & Hoffman, J.I. What a seal´s smell can tell – investigating the chemical basis of seal olfaction. Speed talk at the 22. Marine Mammal Biennial Conference, 2015, San Francisco. Slides: smm2015_talk_final. (Award for the best pre-doctoral speed talk; travel grant)
- Cesare V Parise, Martin Stoffel & Marc O Ernst (2014) Multisensory classification images reveal the role of cross-correlation in audiovisual temporal processing. Poster presented at the VSS conference, Florida.
- Stoffel, M., Reis, D., Schwarz, D. & Schröder, A. (2012). The influence of coping strategies on psychological stress in chronic pain patients. Poster presented at the German Congress of Psychosomatic Medicine and Psychotherapy, Munich.
- Proceedings of the Royal Society B.
Department of Animal Behaviour
School of Natural Sciences and Psychology
Liverpool John Moores University
I am funded by:
Genetics Society, Heredity Fieldwork Grant