Insect phylogeography

We study genetic variation within various insect species, for the purpose of inferring their evolutionary history and/or evaluating their capacity to disperse.

Among others:

- we investigated the influence of past climate changes that occurred during the late Pleistocene on several cold-adapted leaf beetles currently displaying a boreo-montane distribution in Europe and North America,

Mardulyn P., MikhailovY.E., Pasteels J.M. 2009. Testing phylogeographic hypotheses in a Euro-Siberian cold-adapted leaf beetle with coalescent simulations. Evolution , 63:2717-2729. [PDF]

Mardulyn P., Othmezouri N., Mikhailov Y.E., Pasteels J.M. 2011. Conflicting mitochondrial and nuclear phylogeographic signals and evolution of host-plant shifts in the boreo-montane leaf beetle Chrysomela lapponica. Molecular Phylogenetics and Evolution, 61:686-696. [PDF]

Dellicour S., Fearnley S., Lombal A., Heidl S., Dahlohff E., Rank N. E., Mardulyn P. 2014. Inferring the past and present connectivity across the range of a North American leaf beetle: combining ecological-niche modeling and a geographically explicit model of coalescence. Evolution, 68:2371-2385. [PDF]

Quinzin M. C., Normand S., Dellicour S., Svenning J.C., Mardulyn P. 2017. Glacial survival of trophically linked boreal species in northern Europe. Proceedings of the Royal Society B, 284: 20162799.

- we conducted several comparative phylogeographic studies (leaf beetles, bark beetles, bees), comparing variation at multiple loci across several species, to investigate the combined influence of species-specific traits (host plant abundance, dispersal) and environmental disturbances on phylogeographic patterns, or to explore inter-species hybridization through patterns of mitochondrial and nuclear introgression

Quinzin M. C., Mardulyn P. 2014. Multi-locus DNA sequence variation in a complex of four leaf beetle species with parapatric distributions: Mitochondrial and nuclear introgressions reveal recent hybridization. Molecular Phylogenetics and Evolution, 78:14-24. [PDF]

Dellicour S., Michez D., Rasplus J., Mardulyn P. 2015. Impact of past climatic changes and resource availability on the population demography of three food-specialist bees. Molecular Ecology, 24: 1074-1090. [PDF]

Mayer F., Piel F.B., Cassel-Lundhagen A., Kirichenko N., Grumiau L., Økland B., Bertheau C., Grégoire J.-C., Mardulyn P. 2015. Comparative multi-locus phylogeography of two Palaearctic spruce bark beetles: influence of contrasting ecological strategies on genetic variation. Molecular Ecology, 24:1292-1310. [PDF]

Dellicour S., Michez D., Mardulyn P. 2015. Comparative phylogeography of five bumblebees: impact of range fragmentation, range size and diet specialisation. Biological Journal of the Linnean Society, in press. [PDF]

- we evaluated current migration in a leaf beetle species at the landscape level

Mardulyn P., Milinkovitch M. C. 2005. Inferring contemporary levels of gene flow and demographic history in a local population of the leaf beetle Gonioctena olivacea from mitochondrial DNA sequence variation. Molecular Ecology, 14:1641-1653. [PDF]

- we evaluated the mode of colonization of a solitary bee that went through a recent range expansion in Europe

Dellicour S., Mardulyn P., Hardy O. J., Hardy C., Roberts S.P.M., Vereecken N. J. 2014. Inferring the mode of colonisation of the rapid range expansion of a solitary bee from multi-locus DNA sequence variation. Journal of Evolutionary Biology, 27:116-132. [PDF]

- we compared hypotheses over the colonization of Italy by the insect vector of the bluetongue virus, Culicoides imicola

Mardulyn P., Goffredo M., Conte A., Hendrickx G., Meiswinkel R., Balenghien T., Sghaier S., Lohr Y., Gilbert M. 2013. Climate change and the spread of vector-borne diseases: using approximate Bayesian computation to compare invasion scenarios for the bluetongue virus vector Culicoides imicola in Italy. Molecular Ecology, 22:2456-2466. [PDF]

Speciation and hybridization in leaf beetles

We are studying hybridization between two sister species of cold-resistant leaf beetles inside a hybrid zone, and are evaluating its consequences on species divergence and genomic variation.

After having established the occurence of mitochondrial genome introgression from Gonioctena quinquepunctata to G. intermedia, inside their hybrid zone in the Alps (Quinzin and Mardulyn 2014), We first attempted to evaluate introgression at the level of the nuclear genome using RAD-seq markers. Analyzing these RAD-seq data provided very little evidence that introgression was taking place inside the nuclear genome.

Kastally C., Trasoletti M., Mardulyn P. 2019. Limited gene exchange between two sister species of leaf beetles within a hybrid zone in the Alps. Journal of Evolutionary Biology, 32: 1406-1417. [PDF: see Publication request page]

We then proceeded to evaluate this using whole genome sequencing of multiple individuals from their hybrid zone in the Alps. Analyzing whole genome sequence variation with a machine learning approach, we were able to detect asymetric introgression: about 2% of the nuclear genome was transferred from G. quinquepunctata to G. intermedia, thus in the same direction than was observed for the mitochondrial genome. We suggested that this asymetric introgression was caused by the recent invasion of the range of G. quinqupeunctata by G. intermedia, and that some of the introgressed regions may have been favored by natural selection. Could the introgressed alleles have facilitated the colonization of the Alpine habitat by G. intermedia?

Lukicheva S., Mardulyn P. 2021. Whole genome sequencing reveals asymetric introgression between two sister species of cold-resistant leaf beetles. Molecular Ecology, 30: 4077-4089. [open access]

For the purpose of analyzing genomic variation within the two species, we also generated a reference assembly and annotation for the genome of G. quinquepunctata.

Lukicheva S., Flot J.-F., Mardulyn P. 2021. Genome assembly of the cold-tolerant leaf beetle Gonioctena quinquepunctata, an important resource for studying its evolution and reproductive barriers between species. Genome Biology and Evolution, 13: evab134. [open access]

Evaluation and development of methods to analyze DNA sequence variation in an evolutionary context

We have evaluated several methods we rely upon to analyse DNA sequence variation

Cassens I., Mardulyn P., Milinkovitch M. C. 2005. Evaluating intraspecific "Network" construction methods using simulated sequence data: do existing algorithms outperform the global maximum parsimony approach? Systematic Biology, 54:363-372. [PDF]

Mardulyn P., Vaesen A., Milinkovitch M.C. 2008. Controlling population evolution in the laboratory to evaluate methods of historical inference. PLoS ONE , 3(8): e2960. [PDF]

Mardulyn P., Cassens I., Milinkovitch M.C. 2009. A comparison of methods constructing evolutionary networks from intraspecific DNA sequences. Pages 104-120 in Population Genetics for Animal Conservation (eds G Bertorelle, MW Bruford, HC Hauffe, A Rizzoli, C Vernesi). Cambridge University Press, Cambridge, UK.

Mardulyn P. 2012. Trees and/or networks to display intraspecific DNA sequence variation? Molecular Ecology, 21:3385-3390. [PDF]

Quinzin M. C., Mayer F., Elvinger N., Mardulyn P. 2015. Theoretical expectations of the Isolation-Migration model of population evolution for inferring demographic parameters. Methods in Ecology and Evolution, 6: 610-620. [PDF]

A large variety of analytical tools are already available to explore genetic variation data. We have also developped a few programs. 

Dellicour S., Kastally C., Hardy O. J., Mardulyn P. 2014. Comparing phylogeographic hypotheses by simulating DNA sequences under a spatially explicit model of coalescence. Molecular Biology and Evolution, 31:3359-3372. [PDF] [software download]

Dellicour S., Mardulyn P. 2014. SPADS 1.0: a toolbox to perform spatial analyses on DNA sequence datasets. Molecular Ecology Resources, 14:647-651. [PDF] [software download]

Branders V., Mardulyn P. 2016. Improving intraspecific allele networks inferred by maximum parsimony. Methods in Ecology and Evolution, 7:90-95. [PDF] [software download