Origin, maintenance and evolution of colour polymorphism

Sex-limited colour polymorphisms are common in odonates (dragonflies and damselflies). In fact, more than 100 odonate species with a female-limited colour polymorphism have been described, althought the degree of polymorphism varies markedly within families and genus

1) Selective and stochastic processes governing colour polymorphism in damselflies
2) Female morph and morph specific mating frequencies
3) Innate male preferences 
4) Ontogenetic changes in male preference for female morphs suggest that male mating harassment and learning preferences may promote the maintenance of this colour polymorphism in females through density- and frequency-dependent processes

Presentations to test male mating preferences

Female-limited colour polymorphism in the two closely related Ischnura species I. elegans and I. graellsii. Androchrome females exhibit a blue-green thorax coloration, similar to conspecific males. However, gynochrome females, infuscans and infuscans-obsoleta, show less conspicuous mature thorax coloration (green-brown). Additionally, the eight abdominal segment in mature androchrome is blue (as in males), while in gynochrome females this segment is brown

Population and mating frequencies of the androchrome females for the polymorphic Ischnura elegans. The diagonal indicates the expected relation if females mate in direct proportion to their population frequency

Hybridization and speciation

1) Evolution of pre- and post-zygotic reproductive
isolation in damselflies

2) Correlation between reproductive isolation and genetic divergence in sympatric versus allopatric distributions

3) The role of natural versus sexual selection on the speciation processes on odonates

4) Evolutionary consequences of climate-induced range shifts in odonates

Ischnura elegans and I. graellsii: A) Distribution of I. elegans (green) and I. graellsii (red) in Europe. B) Ischnura elegans and I. graellsii males. C) Results from a MaxEnt model of the predicted future (2050) distribution of I. elegans, ranging from highly suitable (red, orange) to less suitable (yellow, green)4.

Relative contributions to total isolation in reciprocal crosses (G × E: I. graellsii females and I. elegans males, E × G: I. elegans females and I. graellsii males following the method described by Ramsey et al. (2003). Graph (A) includes all sympatric barriers, that is, excluding habitat and temporal isolation while graph (B) includes all sympatric and allopatric barriers

• Hybridization and speciation genomics

This project is focused on two closely related damselfly species, Ischnura elegans and I. graellsii, which show extensive and recent population overlap in southern Europe with strong and on-going hybridisation. 
This project has three main objectives that will address key challenges in the field:
1) Detailed quantification of introgression levels across the genome
2) Repeatability of the genetic architecture of speciation 
3) Repeatability of the genetic architecture of adaptation via introgressive hybridization

Schematic diagram of the main procedure. Four parents of both species will be selected to create a pedigree (parental species; F1 hybrids; and F2 backcross). Parents, F1 hybrids and F2 backcrosses will be sequenced using NGS technologies. Diagnostic SNPs between parental species will be identified. Blocks of haplotypes and recombination maps will be created and will be use as markers for conservation genetics