Christine Vaz, University of Seville. Supervisors: Juan Arroyo Marín, Rocío Santos Gally & Juan Núñez-Farfán. Start in 2016.
Summary:
Datura stramonium is a cosmopolitan invasive
species whose native area is situated in México and surrounding regions.
It is currently present in almost all the regions of the world with
temperate and warm climate.
In this PhD study, we aim to determine whether the invasion by this
species across the world is related with a shift from herkogamy to a
non-herkogamous condition, that is, if separation of sex organs is
reduced for reproductive assurance and if subsequently it means a lower
phenotypic and genetic variation.
Datura stramonium was probably first introduced in Europe in the
16th century, entering through southwestern Spain, where trade with the
Americas has been intense since that period. Since the species has an
annual life cycle, in this region there is enough time (in terms of
number of generations) for a shift towards higher herkogamy, compared to
more recently colonized areas where herkogamy could be reduced, to
ensure reproduction.
We aim to reconstruct the invasion route of Datura stramonium, in
the Old World and within the Americas by analyzing populations of the
species from all over the world and by crossing the phylogeographical
information with historical records from herbaria, references,
citations, etc.
Furthermore, the ecological niche of the species will be characterized
in order to determine if there is a niche shift between the native and
the introduced range, shift that could be involved in this evolutionary
process.
The ultimate goal is to assess if a human-mediated process that started
in the 16th century (across the Old World) or even earlier (across the
New World) has promoted evolutionary change.