Guschanski lab: Research

Ecological, climatic, and anthropogenic effects on animal population dynamics

Studying the dynamics of wild animal populations provides insights into many aspects of their ecology and behavior, informs conservation efforts, and, in case of primates, sheds light on the evolutionary processes that have likely shaped our own species. Using field research data on species ecology and behavior in combination with in-depth molecular analyses of field-collected samples we study spatial genetic structure, sex-biased dispersal, individual variation in dispersal abilities, and individual habitat preferences.

Fig. 1 Genetic structure in mountain gorillas is driven by habitat similarity. Circles represent gorilla groups or solitary males, with colors corresponding to the proportion of the group’s genome attributed to one of the three genetic clusters. The background represents the plant community composition, with similar shading of grey showing areas of similar vegetation composition. Note how genetically similar groups cluster within similarly grey zones. From Guschanski et al. 2008, Curr Biol.

Currently, we are collaborating with the Dian Fossey Gorilla Fund International and the Max Planck Institute for Evolutionary Anthropology in our work on eastern lowland gorillas (Gorilla beringei graueri).

Studies that combine contemporary and historical samples markedly refine our understanding of population-level processes. Historical samples are tremendously important when changes in genetic diversity, species distribution, and population relationships need to be investigated over time, as they provide a window into the past. They further allow us to analyze demographic changes and to study factors responsible for these changes, including climatic, environmental and anthropogenic effects. We benefit from collaborations with a number of European museums including Museum für Naturkunde in Berlin, Germany; Royal Museum for Central Africa in Tervuren, Belgium; Royal Belgian Institute of Natural Sciences in Brussels, Belgium; Natural History Museum in London, United Kingdom and Naturhistoriska Riksmuseet in Stockholm (http://www.nrm.se/english.16_en.html), Sweden.


Species diversity and speciation processes

The availability of genomic tools allows us to study the role of hybridization and introgression in generating species diversity. Because hybridization status is frequently used to inform conservation decisions, it is crucial to provide a clear view on the importance of hybridization in shaping species diversity. Many primate taxa are known to hybridize in the wild and there is evidence that ancient hybridization might have been important in some lineages.
 

Fig. 2 Dated guenon phylogeny based on mitochondrial DNA sequences. Circles at the nodes represent the geographical ranges of the ancestral taxa. Grey bars indicate the timings of four important speciation events, each of which coincides with major climatic events in western and eastern Africa. Taxa in red are terrestrial and the phylogenetic tree indicates three independent transitions to terrestirality. From Guschanski et al. 2013, Syst Biol

We are studying these processes in guenons and use both field-collected and museum samples to elucidate the importance of ancient and present-day hybridization in these and other taxa.


Genomic innovation, morphological and behavioral trait evolution

Elucidating the effect of genetic variants and genomic innovations on character trait evolution is an extremely exciting, but challenging task. Studies in domestic animals, such as dogs, horses and cattle identified genes underlying many interesting morphological traits, e.g. muscle growth, body size and coat color variation. However, performing these studies in wild animal populations is hampered by the difficulties in accessing samples from relevant cohorts, generally low sample sizes, and scarcity of available information (e. g. deep genealogies, long-term observations and records). Nevertheless, first attempts to study trait variation in nature have been made and we are interested in contributing to this research field by focusing on characteristics affecting adaptations to sparse and unpredictable resources in primates.


Developing methods for low-quality samples


Working with field-collected noninvasive samples, such as dung, hair, food remains, and with museum-preserved specimens requires a special set of techniques and approaches. This is because the DNA is present in very low quantities, is of low quality, and the samples are extremely precious. Making a large number of such “difficult” samples accessible for genetic and genomic analyses requires development of novel approaches. We engage in development and establishment of techniques suitable for genome-level analyses from such low-quality samples.
 

Collaborators

Damien Caillaud
Department of Anthropology

UC Davis, CA
USA
Webpage

Love Dalén
Department of Bioinformatics and Genetics
Swedish Museum of Natural History
Box 50007, SE-104 05 Stockholm
SWEDEN
Webpage
 

Tomas Marques-Bonet
Institut Biologia Evolutiva
Universitat Pompeu Fabra/CSIC
Aiguader 88, 08003, Barcelona
SPAIN
Webpage