Abstracts (first author)

Talk 

From Africa and back again: biogeography and differentiation of a specialist west-Mediterranean butterfly in a fragmented glacial refuge

Author(s): Marabuto E, Rebelo M, Paulo OS

Summary:

The Mediterranean area is well known for retaining and generating biodiversity during climate and habitat shifts taking place since the end of the Miocene. This important biodiversity hotspot is both the source and the result of a complex process of differentiation and interaction between evolving lineages and their changing environment. However, regarding stationary Mediterranean specialists, which are expected to benefit and expand northwards with climate amelioration, little is still known. Using the butterfly Euchloe tagis, an Atlanto-Mediterranean ecological specialist with a fragmented and restricted distribution, this study attempts at answering pertinent biogeographic aspects on the species and its interaction with the changing ecosystem. We sequenced a 599bp barcode region fragment of the COI gene from all major populations to better understand current its genetic patterns and evolutionary history. Main results suggest an origin in North Africa, from where the sister species Euchloe pechi is endemic. While one of the Moroccan populations diverged earlier from the remaining stock, all remaining are more closely related despite the existence of differentiated major mitochondrial lineages. It seems that Iberia has played a pivotal role in the generation of diversity in this species: two consistent genetic clusters are partly sympatric whereas French and Italian populations are considerably different. The second Moroccan population from the Rif Mountains shows little segregation from French samples and this issue is discussed on a phylogeographic framework supported by molecular-clock analysis. This pattern suggests this species experienced polycentric refugia during climate cycles, leading to such genetic structure and a putative re-colonization of Africa. Moreover, the neutral genetic pattern reported in this study challenges current taxonomy based on morphological differentiation and suggests a more complex evolution of this species.


Poster 

Comparative phylogeography and genetic population structure of two butterfly species from the Iberian Peninsula

Author(s): Marabuto E, Martins R, Silva DN, Seabra SS, Paulo OS

Summary:

The Iberian Peninsula is recognized as one of the most important refugia for temperate species during the cyclic climatic changes of the Plio-Pleistocene glacial periods. Mountainous regions within these refugia areas are also believed to retain high levels of endemism and genetic diversity due to the easily tracked suitable habitats by upward-downward movements. Here we examine population genetic structure, phylogeographic and demographic patterns of Lycaena bleusei, a butterfly species endemic to the Central Iberian Mountain System and contrast this to the patterns found for a congeneric widespread species, also occurring in the Iberian Peninsula, Lycaena tityrus. We use two molecular markers to understand if there is congruency in their evolutionary histories or, conversely, if different evolutionary drivers may have shaped these species differently. We find that the two species, which exhibit similar dispersal abilities and ecological requirements, show different demographic and genetic patterns. We hypothesize that these differences are due to the evolutionary forces acting on species that contracted to southern refugia during the Pleistocene and that, ultimately, drove to population differentiation and speciation. We also find evidence for hybridization events between these two species, with L. bleusei males coming in contact with L. tityrus females on a secondary contact zone described here for the first time.



Abstracts (coauthor)

Experimental and genomic approaches in the study of the balanced colour-polymorphism of the meadow spittlebug (Philaenus spumarius)

Author(s): Seabra, SG, Rodrigues AS, Silva SE, Silva J, Marabuto E, Pina-Martins F, Gharbi K, Blaxter M, Borges PAV, Jiggins C, Quartau JA, Paulo OS

Summary:

Philaenus spumarius (Insecta, Hemiptera, Aphrophoridae) has for long been a subject of interest of evolutionary biologists due to its heritable colour polymorphism that shows evidence of balancing selection and of clinal variation in the colour mophs frequencies. We are studying the adaptive significance of this polymorphism, particularly to understand if the melanic morphs (e.g. “marginellus” morph) have any advantage/disadvantage in terms of survival and reproductive success, efficiency of egg maturation and resistance to desiccation compared to non-melanic morphs (“typicus” and “trilineatus”). Results so far indicate a higher survival, higher number of eggs clutches and higher number of eggs laid by the “trilineatus” females than “typicus” or “marginellus” females. We are also taking a genomic approach for a) the identification of genetic basis of the colour polymorphism and b) for detecting signatures of balancing and directional selection in the genome of P. spumarius. For this purpose we are applying RAD sequencing in a) a set of samples from the three different morphs referred above, using a high frequency cutter enzyme (PstI) and in b) another set of samples from 8 populations across the distribution range of the species representing the main mitochondrial haplogroups, using a lower frequency cutter enzyme (SbfI). We are also assembling a draft of the genome that will aid in the identification of homologous regions to available references, although the very large genome size of this insect constitutes an extra challenge.

Phylogeographic structure of the spittlebug Philaenus spumarius (Hemiptera, Aphrophoridae) based on mitochondrial DNA and RAD sequencing

Author(s): Rodrigues, AS, Silva SE, Marabuto E, Silva DN, Silva J, Wilson MR, Thompson V, Yurtsever S, Halkka A, Gharbi K, Blaxter M, Borges PAV, Quartau JA, Jiggins C, Paulo OS, Seabra SG

Summary:

We investigated the evolutionary history of the meadow spittlebug Philaenus spumarius, a widespread and polyphagous insect species of the Holarctic region, limited in its range by the presence of enough humidity in the earlier life stages, and that has a remarkable dorsal colour/pattern polymorphism of the adults. The mitochondrial gene cytochrome c oxidase subunit I (COI) revealed three main haplogroups in Europe: the “western”, the “eastern-Mediterranean” and the “north-eastern” haplogroups, which overlapped in some regions. Evidence of recent divergence events at less than one million years ago in southern Mediterranean peninsulas followed by northward population expansions were found. Recent gene-flow events between the main southern peninsulas and between the Iberian Peninsula and North Africa were also detected. A probable British origin for the insular populations of the Azores and New Zealand was revealed, as well as multiple geographic origins for North American populations from western and northern Europe. Restriction site associated DNA (RAD) sequencing was also applied in a set of 8 populations from the different mitochondrial haplogroups and the differentiation patterns obtained from a set of over 15,000 SNPs were concordant with COI results and with a better resolved tree.

Contacts

Chairman: Octávio S. Paulo
Tel: 00 351 217500614 direct
Tel: 00 351 217500000 ext22359
Fax: 00 351 217500028
email: mail@eseb2013.com

Address

XIV Congress of the European Society for Evolutionary Biology

Organization Team
Department of Animal Biology (DBA)
Faculty of Sciences of the University of Lisbon
P-1749-016 Lisbon
Portugal

Website

Computational Biology & Population Genomics Group 
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