Tracing the spread of exotic species using genetic markers


This project provides an opportunity for a student to learn molecular genetic laboratory techniques that are useful for a multitude of biological fields including evolution, ecology, physiology, conservation, pharmacology, and medicine.

Project Description


1-Tracing the spread of exotic species using genetic markersHumans are transforming natural landscapes by spreading species far from their native range. These exotic species can impact natural biodiversity and ecosystem functioning, and island ecosystems are especially susceptible to exotic species.

Our work focuses primarily on terrestrial Caribbean herpetofaunal species (amphibians and reptiles) that are often transported passively from one island to another in cargo shipping containers (top figure). In the Caribbean, each island has unique, endemic species that are found nowhere else. In many cases, these species are relocated in a stepping-stone pattern from island to island making it impossible to know a priori whether the exotic species on a particular island originated from its native island or another exotic population. For example in the bottom figure, all of the lines leaving Florida (top left) represent species that are exotic to Florida and are being spread further across the Caribbean (stepping-stone pattern). By using genetic markers, it is possible to identify potential sources of exotic populations. Once the sources of exotics are identified, island nations can enact policies for heightened screening of shipments coming from likely source locations.

The student project will involve conducting genetic analyses using a combination of mitochondrial and nuclear markers on DNA samples that have already been collected for species within their native and exotic ranges. Then the student will use R statistical software to analyze the results and link exotic populations to their likely source populations for each species. Finally, these linked exotic and source populations across several species will be combined to build a genetic invasion network.

Project Goals:

• Conduct molecular genetic analyses on DNA samples from exotic and native populations.
• Use statistical software to link exotic populations to likely source populations for each species.
• Combine results for multiple species to build genetic invasion network.

Student Responsibilities:

• Learn appropriate molecular laboratory techniques to analyze DNA samples.
• Use and learn basic methods in R statistical programming to analyze molecular data.
• Maintain organized and consistent lab notebook and data management scheme.

Location and Timeframe


Lab work and statistical analyses will be conducted at the Center for Biodiversity molecular lab at Temple University, Philadelphia, PA, USA (Note: Student is responsible for travel expenses associated with this project).

Supervision and Information


Dr. Jocelyn Behm (stationed abroad)
j.e.behm@vu.nl

Prof. Dr. Jacintha Ellers (Room H141, W&N building, Vrije Universiteit)
j.ellers@vu.nl