What is the problem we deal with?
Virtually all landscapes are vulnerable to invasive pests that come from outside, establish populations and spread uncontrollably. This is especially true for island ecosystems such as the Hawaiian Islands. Before the arrival of humans in Hawaii, native organisms evolved in relative isolation. Isolated evolution means that these species never experienced the influences of high species diversity and different habitats typical of continents, and never evolved the ability to compete under these types of conditions. An example is grazing; the floras of most isolated islands are severely impacted by recently introduced grazers, as the native plants never had the opportunity or evolutionary stimulus to evolve defense mechanisms such as thorns or toxins against grazers.
Invasions by plants and animals often lead to the loss of species biodiversity, decreased agricultural productivity, and changes in ecosystem processes such as water cycling and fire hazards. This all underscores the necessity for effective ways to identify and manage potential invasive species, and to predict which species pose a particular risk of becoming invasive.
Research on Conservation of Hawaiian Species
Who cares about the molecular biology stuff?
Biologists working on invasive species try to unravel the traits that contribute to invasiveness, so they can identify effective management strategies. DNA technology offers many options for understanding biological problems. The recent developments in this technology allow scientists to address questions related to invasive species that were previously troublesome and often impossible to achieve. For example, biological control (the use of living organisms to control other organisms) is often the only economical option to control pest species. Often, biological controls exist where the pest originated, but that location may be unknown. With DNA sequencing it is now possible to compare pest populations to different native populations to identify the region of origin and thus find effective biological control agents.
The dispersal patterns of known pests can be used to predict the likelihood that newly introduced organisms will also become pests. However, tracking the dispersal of organisms is often problematic, especially for plants. DNA technology can help describe such patterns by indirectly tracing the movement of genes across landscapes since genes disperse in similar fashion as the plant parts (seeds and pollen) that carry them. By comparing such patterns of dispersal to environmental conditions we can identify regions that are most likely to be invaded by similar organisms and prioritize conservation efforts. Dispersal patterns can also indicate which management strategy is likely going to be most productive. For example, if organisms disperse in an “advancing front’, like a forward-marching army, containment of that front would be the best option vs. organisms spreading over long distances where eradication of new populations would be the best strategy.