1) Molecular taxonomy and phylogeography of freshwater and land planarians

The main aim of this line of research is to characterize the major events and processes creating and shaping the diversity and distribution of living organisms. Freshwater and land planarians (Platyhelminthes, Tricladida) have characteristics, as low dispersive capacity and high sensibility to environment changes, that make of them good models to be used in biogeographical analyses and as biodiversity indicators. Using molecular data based technologies we are establishing the phylogenetic framework for the whole group (Tricladida), and within selected genus. With this knowledge we have identified specific cases of interest in which we focus our research to analyse different aspects of biodiversity:

The effects of sex/no-sex. Study of asexual (fissiparous) forms of the freshwater genera Dugesia and Schmidtea geographically widespread in the Mediterranean to unveil whether they are ancient or recent; how they accumulate mutations and how do they keep with the load of deleterious mutations. In short, to answer: What does them so successful in this area?

Diversification. Analysis of diverse freshwater and terrestrial planarians species in particular regions to unravel the effects of the historical (geological, climatic, geographic barriers) events in the origin and present distribution of genetic diversity within species, and as mechanisms to produce speciation.

Invasive species. Study of populations of new-coming terrestrial planarians, originary from places as distant as Sudamerica and Australia, found in different places in the Iberian Peninsula. This study can help us evaluate the effects of human trade in present biodiversity distribution, and evaluate the dangers these movements can represent for other soil inhabitants.

Conservation and management. The knowledge acquired in the previous points is necessary to advice conservation policies and to establish protected areas.

To fulfill all this points we are working with different species of planarians in the Mediterranean region and also in the Atlantic Forest of Brazil, both considered hotspots of Biodiversity and with complex geological and climatic histories. Moreover, the Atlantic Forest is at present reduced to a ~16% of its extension 500 years ago. We have been mainly using COI and ITS-1 sequences in our studies, but at present are developing new markers, by sequencing complete mitochondrial genomes and using high-throughput technologies to pinpoint nuclear genome regions adequate for our analysis. Bayesian and maximum likelihood based methodologies and coalescence analysis also allow us to produce well supported trees, date events, analyse demographic processes and contrast evolutionary scenarios with statistical rigorousness.

Constructing robust phylogenies is central to understand the origin and radiation of any animal clade. As today, the origin, radiation and relationships of some phyla within the Bilateria are still not settled, even after using tenth or hundreds of thousands of bp to infer phylogenies. Prominent among them is the unsettled position of the Platyhelminthes (flatworms), Gastrotricha, Gnathostomulida and Xenoturbella. Our approach searches molecular synapomorphies: to check EST and genomic collections in search of shared genomic rare changes among phylums.